all-in-one-event-calendar/lib/cache/strategy/apc.php
2017-11-09 17:36:04 +01:00

118 lines
3.1 KiB
PHP

<?php
/**
* Concrete class for APC caching strategy.
*
* @instantiator new
* @author Time.ly Network, Inc.
* @since 2.0
* @package Ai1EC
* @subpackage Ai1EC.Cache.Strategy
*/
class Ai1ec_Cache_Strategy_Apc extends Ai1ec_Cache_Strategy {
/**
* is_available method
*
* Checks if APC is available for use.
* Following pre-requisites are checked: APC functions availability,
* APC is enabled via configuration and PHP is not running in CGI.
*
* @return bool Availability
*/
static public function is_available() {
return function_exists( 'apc_store' ) &&
function_exists( 'apc_fetch' ) &&
ini_get( 'apc.enabled' ) &&
( false === strpos( php_sapi_name(), 'cgi' ) );
}
/**
*
* @see Ai1ec_Get_Data_From_Cache::get_data()
*
*/
public function get_data( $dist_key ) {
$key = $this->_key( $dist_key );
$data = apc_fetch( $key );
if ( false === $data ) {
throw new Ai1ec_Cache_Not_Set_Exception( "$dist_key not set" );
}
return $data;
}
/**
*
* @see Ai1ec_Write_Data_To_Cache::write_data()
*
*/
public function write_data( $dist_key, $value ) {
$key = $this->_key( $dist_key );
$store_method = 'apc_add';
if ( false !== ( $existing = apc_fetch( $key ) ) ) {
if ( $value === $existing ) {
return true;
}
$store_method = 'apc_store';
} elseif ( false === function_exists( $store_method ) ) {
$store_method = 'apc_store';
}
if ( false === $store_method( $key, $value ) ) {
try {
if ( $value !== $this->get_data( $key ) ) {
throw new Ai1ec_Cache_Not_Set_Exception( 'Data mis-match' );
}
} catch ( Ai1ec_Cache_Not_Set_Exception $excpt ) {
throw new Ai1ec_Cache_Not_Set_Exception(
'Failed to write ' . $dist_key . ' to APC cache'
);
}
}
return true;
}
/**
* (non-PHPdoc)
* @see Ai1ec_Write_Data_To_Cache::delete_data()
*/
public function delete_data( $key ) {
if ( false === apc_delete( $this->_key( $key ) ) ) {
return false;
}
return true;
}
/**
*
* @see Ai1ec_Write_Data_To_Cache::delete_matching()
*/
public function delete_matching( $pattern ) {
// not implemented - concider flushing APC cache
return 0;
}
/**
* _key method
*
* Make sure we are on the safe side - in case of multi-instances
* environment some prefix is required.
*
* @param string $key Key to be used against APC cache
*
* @return string Key with prefix prepended
*/
protected function _key( $key ) {
static $prefix = null;
if ( NULL === $prefix ) {
$prefix = substr( md5( ai1ec_get_site_url() ), 0, 8 );
}
if ( 0 !== strncmp( $key, $prefix, 8 ) ) {
$key = $prefix . $key;
}
return $key;
}
}