<?php
  /**
   * Copyright (c) 2012 Bart Visscher <bartv@thisnet.nl>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */

  namespace OC\Memcache;

  /**
   * See http://xcache.lighttpd.net/wiki/XcacheApi for provided constants and
   * functions etc.
   */

  class XCache extends Cache {

  	/**

  	 * entries in XCache gets namespaced to prevent collisions between ownCloud instances and users

  	 */
  	protected function getNameSpace() {
  		return $this->prefix;
  	}
  
  	public function get($key) {
  		return xcache_get($this->getNamespace().$key);
  	}
  
  	public function set($key, $value, $ttl=0) {
  		if($ttl>0) {
  			return xcache_set($this->getNamespace().$key, $value, $ttl);
  		}else{
  			return xcache_set($this->getNamespace().$key, $value);
  		}
  	}
  
  	public function hasKey($key) {
  		return xcache_isset($this->getNamespace().$key);
  	}
  
  	public function remove($key) {
  		return xcache_unset($this->getNamespace().$key);
  	}
  
  	public function clear($prefix='') {

  		if (function_exists('xcache_unset_by_prefix')) {
  			return xcache_unset_by_prefix($this->getNamespace().$prefix);
  		} else {
  			// Since we can not clear by prefix, we just clear the whole cache.
  			xcache_clear_cache(\XC_TYPE_VAR, 0);
  		}

  		return true;
  	}

  
  	static public function isAvailable(){
  		if (!extension_loaded('xcache')) {
  			return false;

  		}
  		if (\OC::$CLI) {

  			return false;

  		}

  		if (!function_exists('xcache_unset_by_prefix') && ini_get('xcache.admin.enable_auth')) {
  			// We do not want to use XCache if we can not clear it without
  			// using the administration function xcache_clear_cache()
  			// AND administration functions are password-protected.
  			return false;
  		}
  		$var_size = (int) ini_get('xcache.var_size');
  		if (!$var_size) {
  			return false;
  		}
  		return true;

  	}

  }