File size: 8.72Kb
<?php
/**
* SocialEngine
*
* @category Engine
* @package Engine_Cache
* @copyright Copyright 2006-2017 Webligo Developments
* @license http://www.socialengine.com/license/
*/
class Engine_Cache_Backend_Apc extends Zend_Cache_Backend implements Zend_Cache_Backend_ExtendedInterface
{
/**
* Log message
*/
const TAGS_UNSUPPORTED_BY_CLEAN_OF_APC_BACKEND = 'Zend_Cache_Backend_Apc::clean() : tags are unsupported by the Apc backend';
const TAGS_UNSUPPORTED_BY_SAVE_OF_APC_BACKEND = 'Zend_Cache_Backend_Apc::save() : tags are unsupported by the Apc backend';
/**
* Constructor
*
* @param array $options associative array of options
* @throws Zend_Cache_Exception
*/
public function __construct(array $options = array())
{
if( !extension_loaded('apcu') ) {
Zend_Cache::throwException('The apcu extension must be loaded for using this backend !');
}
parent::__construct($options);
}
/**
* Test if a cache is available for the given id and (if yes) return it (false else)
*
* WARNING $doNotTestCacheValidity=true is unsupported by the Apc backend
*
* @param string $id cache id
* @param boolean $doNotTestCacheValidity if set to true, the cache validity won't be tested
* @return string cached datas (or false)
*/
public function load($id, $doNotTestCacheValidity = false)
{
$tmp = apcu_fetch($id);
if( is_array($tmp) ) {
return $tmp[0];
}
return false;
}
/**
* Test if a cache is available or not (for the given id)
*
* @param string $id cache id
* @return mixed false (a cache is not available) or "last modified" timestamp (int) of the available cache record
*/
public function test($id)
{
$tmp = apcu_fetch($id);
if( is_array($tmp) ) {
return $tmp[1];
}
return false;
}
/**
* Save some string datas into a cache record
*
* Note : $data is always "string" (serialization is done by the
* core not by the backend)
*
* @param string $data datas to cache
* @param string $id cache id
* @param array $tags array of strings, the cache record will be tagged by each string entry
* @param int $specificLifetime if != false, set a specific lifetime for this cache record (null => infinite lifetime)
* @return boolean true if no problem
*/
public function save($data, $id, $tags = array(), $specificLifetime = false)
{
$lifetime = $this->getLifetime($specificLifetime);
$result = apcu_store($id, array($data, time(), $lifetime), $lifetime);
if( count($tags) > 0 ) {
$this->_log(self::TAGS_UNSUPPORTED_BY_SAVE_OF_APC_BACKEND);
}
return $result;
}
/**
* Remove a cache record
*
* @param string $id cache id
* @return boolean true if no problem
*/
public function remove($id)
{
return apcu_delete($id);
}
/**
* Clean some cache records
*
* Available modes are :
* 'all' (default) => remove all cache entries ($tags is not used)
* 'old' => unsupported
* 'matchingTag' => unsupported
* 'notMatchingTag' => unsupported
* 'matchingAnyTag' => unsupported
*
* @param string $mode clean mode
* @param array $tags array of tags
* @throws Zend_Cache_Exception
* @return boolean true if no problem
*/
public function clean($mode = Zend_Cache::CLEANING_MODE_ALL, $tags = array())
{
switch( $mode ) {
case Zend_Cache::CLEANING_MODE_ALL:
return apcu_clear_cache();
break;
case Zend_Cache::CLEANING_MODE_OLD:
$this->_log("Zend_Cache_Backend_Apc::clean() : CLEANING_MODE_OLD is unsupported by the Apc backend");
break;
case Zend_Cache::CLEANING_MODE_MATCHING_TAG:
case Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG:
case Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG:
$this->_log(self::TAGS_UNSUPPORTED_BY_CLEAN_OF_APC_BACKEND);
break;
default:
Zend_Cache::throwException('Invalid mode for clean() method');
break;
}
}
/**
* Return true if the automatic cleaning is available for the backend
*
* DEPRECATED : use getCapabilities() instead
*
* @deprecated
* @return boolean
*/
public function isAutomaticCleaningAvailable()
{
return false;
}
/**
* Return the filling percentage of the backend storage
*
* @throws Zend_Cache_Exception
* @return int integer between 0 and 100
*/
public function getFillingPercentage()
{
$mem = apcu_sma_info(true);
$memSize = $mem['num_seg'] * $mem['seg_size'];
$memAvailable= $mem['avail_mem'];
$memUsed = $memSize - $memAvailable;
if( $memSize == 0 ) {
Zend_Cache::throwException('can\'t get apc memory size');
}
if( $memUsed > $memSize ) {
return 100;
}
return ((int) (100. * ($memUsed / $memSize)));
}
/**
* Return an array of stored tags
*
* @return array array of stored tags (string)
*/
public function getTags()
{
$this->_log(self::TAGS_UNSUPPORTED_BY_SAVE_OF_APC_BACKEND);
return array();
}
/**
* Return an array of stored cache ids which match given tags
*
* In case of multiple tags, a logical AND is made between tags
*
* @param array $tags array of tags
* @return array array of matching cache ids (string)
*/
public function getIdsMatchingTags($tags = array())
{
$this->_log(self::TAGS_UNSUPPORTED_BY_SAVE_OF_APC_BACKEND);
return array();
}
/**
* Return an array of stored cache ids which don't match given tags
*
* In case of multiple tags, a logical OR is made between tags
*
* @param array $tags array of tags
* @return array array of not matching cache ids (string)
*/
public function getIdsNotMatchingTags($tags = array())
{
$this->_log(self::TAGS_UNSUPPORTED_BY_SAVE_OF_APC_BACKEND);
return array();
}
/**
* Return an array of stored cache ids which match any given tags
*
* In case of multiple tags, a logical AND is made between tags
*
* @param array $tags array of tags
* @return array array of any matching cache ids (string)
*/
public function getIdsMatchingAnyTags($tags = array())
{
$this->_log(self::TAGS_UNSUPPORTED_BY_SAVE_OF_APC_BACKEND);
return array();
}
/**
* Return an array of stored cache ids
*
* @return array array of stored cache ids (string)
*/
public function getIds()
{
$ids = array();
$iterator = new APCUIterator('user', null, APC_ITER_KEY);
foreach( $iterator as $item ) {
$ids[] = $item['key'];
}
return $ids;
}
/**
* Return an array of metadatas for the given cache id
*
* The array must include these keys :
* - expire : the expire timestamp
* - tags : a string array of tags
* - mtime : timestamp of last modification time
*
* @param string $id cache id
* @return array|bool array of metadatas (false if the cache id is not found)
*/
public function getMetadatas($id)
{
$tmp = apcu_fetch($id);
if( is_array($tmp) ) {
$data = $tmp[0];
$mtime = $tmp[1];
if( !isset($tmp[2]) ) {
return false;
}
$lifetime = $tmp[2];
return array(
'expire' => $mtime + $lifetime,
'tags' => array(),
'mtime' => $mtime
);
}
return false;
}
/**
* Give (if possible) an extra lifetime to the given cache id
*
* @param string $id cache id
* @param int $extraLifetime
* @return boolean true if ok
*/
public function touch($id, $extraLifetime)
{
$tmp = apcu_fetch($id);
if( is_array($tmp) ) {
$data = $tmp[0];
$mtime = $tmp[1];
if( !isset($tmp[2]) ) {
return false;
}
$lifetime = $tmp[2];
$newLifetime = $lifetime - (time() - $mtime) + $extraLifetime;
if( $newLifetime <=0 ) {
return false;
}
apcu_store($id, array($data, time(), $newLifetime), $newLifetime);
return true;
}
return false;
}
/**
* Return an associative array of capabilities (booleans) of the backend
*
* The array must include these keys :
* - automatic_cleaning (is automating cleaning necessary)
* - tags (are tags supported)
* - expired_read (is it possible to read expired cache records
* (for doNotTestCacheValidity option for example))
* - priority does the backend deal with priority when saving
* - infinite_lifetime (is infinite lifetime can work with this backend)
* - get_list (is it possible to get the list of cache ids and the complete list of tags)
*
* @return array associative of with capabilities
*/
public function getCapabilities()
{
return array(
'automatic_cleaning' => false,
'tags' => false,
'expired_read' => false,
'priority' => false,
'infinite_lifetime' => false,
'get_list' => true
);
}
}