[task/acm-refactor] Refactor the ACM classes to have a common interface.

They are now refered to as cache drivers rather than ACM classes. The
additional utility functions from the original cache class have been
moved to the cache_service. The class loader is now instantiated without
a cache instance and passed one as soon as it is constructed to allow
autoloading the cache classes.

PHPBB3-9983

phpBB/includes/cache/driver/apc.php

@@ -0,0 +1,76 @@
+<?php
+/**
+*
+* @package acm
+* @version $Id$
+* @copyright (c) 2005, 2009 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+*
+*/
+
+/**
+* @ignore
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+/**
+* ACM for APC
+* @package acm
+*/
+class phpbb_cache_driver_apc extends phpbb_cache_driver_memory
+{
+	var $extension = 'apc';
+
+	/**
+	* Purge cache data
+	*
+	* @return void
+	*/
+	function purge()
+	{
+		apc_clear_cache('user');
+
+		parent::purge();
+	}
+
+	/**
+	* Fetch an item from the cache
+	*
+	* @access protected
+	* @param string $var Cache key
+	* @return mixed Cached data
+	*/
+	function _read($var)
+	{
+		return apc_fetch($this->key_prefix . $var);
+	}
+
+	/**
+	* Store data in the cache
+	*
+	* @access protected
+	* @param string $var Cache key
+	* @param mixed $data Data to store
+	* @param int $ttl Time-to-live of cached data
+	* @return bool True if the operation succeeded
+	*/
+	function _write($var, $data, $ttl = 2592000)
+	{
+		return apc_store($this->key_prefix . $var, $data, $ttl);
+	}
+
+	/**
+	* Remove an item from the cache
+	*
+	* @access protected
+	* @param string $var Cache key
+	* @return bool True if the operation succeeded
+	*/
+	function _delete($var)
+	{
+		return apc_delete($this->key_prefix . $var);
+	}
+}