<?php
  /**
   * Copyright (c) 2013 Robin Appelman <icewind@owncloud.com>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */
  
  namespace OC\Memcache;

  use \OCP\ICacheFactory;
  
  class Factory implements ICacheFactory {
  	/**
  	 * @var string $globalPrefix
  	 */
  	private $globalPrefix;
  
  	/**
  	 * @param string $globalPrefix
  	 */
  	public function __construct($globalPrefix) {
  		$this->globalPrefix = $globalPrefix;
  	}

  	/**
  	 * get a cache instance, will return null if no backend is available
  	 *
  	 * @param string $prefix
  	 * @return \OC\Memcache\Cache
  	 */
  	function create($prefix = '') {

  		$prefix = $this->globalPrefix . '/' . $prefix;

  		if (XCache::isAvailable()) {
  			return new XCache($prefix);
  		} elseif (APCu::isAvailable()) {
  			return new APCu($prefix);
  		} elseif (APC::isAvailable()) {
  			return new APC($prefix);
  		} elseif (Memcached::isAvailable()) {
  			return new Memcached($prefix);
  		} else {
  			return null;
  		}
  	}
  
  	/**
  	 * check if there is a memcache backend available
  	 *
  	 * @return bool
  	 */
  	public function isAvailable() {
  		return XCache::isAvailable() || APCu::isAvailable() || APC::isAvailable() || Memcached::isAvailable();
  	}
  
  	/**
  	 * get a in-server cache instance, will return null if no backend is available
  	 *
  	 * @param string $prefix

  	 * @return null|Cache

  	 */

  	public function createLowLatency($prefix = '') {
  		$prefix = $this->globalPrefix . '/' . $prefix;

  		if (XCache::isAvailable()) {
  			return new XCache($prefix);
  		} elseif (APCu::isAvailable()) {
  			return new APCu($prefix);
  		} elseif (APC::isAvailable()) {
  			return new APC($prefix);
  		} else {
  			return null;
  		}
  	}
  
  	/**
  	 * check if there is a in-server backend available
  	 *
  	 * @return bool
  	 */

  	public function isAvailableLowLatency() {

  		return XCache::isAvailable() || APCu::isAvailable() || APC::isAvailable();
  	}
  
  
  }