Ticket #331: Cache_Xcache.php

<?php defined('SYSPATH') or die('No direct script access.');
/**
 * xcache-based Cache driver.
 *
 * @package    Cache
 * @author     Kohana Team
 * @copyright  (c) 2007-2008 Kohana Team
 * @license    http://kohanaphp.com/license.html
 */
class Cache_Xcache_Driver implements Cache_Driver {

    public function __construct()
    {
        if ( ! extension_loaded('xcache'))
            throw new Kohana_Exception('cache.extension_not_loaded', 'xcache');
    }

    public function get($id)
    {
        if (xcache_isset($id)) 
            return xcache_get($id);
            
        return false;
    }

    public function set($id, $data, $tags, $expiration)
    {
        count($tags) and Log::add('error', 'Cache: tags are unsupported by the Xcache driver');

        return xcache_set($id, $data, $expiration);
    }

    public function find($tag)
    {
        return false;
    }

    public function delete($id, $tag = false)
    {
        if ($id === true)
        {
            return apc_clear_cache('user');
        }
        elseif ($tag == FALSE)
        {
            $result = true;
            $this->auth();
            for($i = 0, $max = xcache_count(XC_TYPE_VAR); $i < $max; $i++) 
            {
                if ( ! xcache_clear_cache(XC_TYPE_VAR, $i)) 
                {
                    $result = false;
                    break;
                }
            }
            
            $this->auth(true);
            return $result;
        }
        else
        {
            return true;
        }
    }

    public function delete_expired()
    {
        return true;
    }

    private function auth($reverse = false) 
    {
        static $backup = array();
    
        $keys = array('PHP_AUTH_USER', 'PHP_AUTH_PW');
        
        foreach ($keys as $key) 
        {
            if ($reverse) 
            {
                if (isset($backup[$key])) 
                {
                    $_SERVER[$key] = $backup[$key];
                    unset($backup[$key]);
                } 
                else 
                {
                    unset($_SERVER[$key]);
                }
            } 
            else 
            {
                $value = env($key);
                
                if ( ! empty($value)) 
                {
                    $backup[$key] = $value;
                }
                $varName = '__' . $key;
                $_SERVER[$key] = Config::item('cache_xcache.'.$varName);
            }
        }
    }

} // End Cache Xcache Driver