<?php
/**
 * Caches ACL checks to reduce load on database
 *
 * core.php:
 * Configure::write ('Acl.classname', 'CacheDbAcl');
 * Configure::write ('CacheDbAcl.cache', 'apc_acl');
 *
 * Cache::config ('apc_acl', array (...));
 *
 */

App::uses('AclInterface', 'Controller/Component/Acl');
App::uses('DbAcl', 'Controller/Component/Acl');

class CacheDbAcl extends DbAcl
{
    private $cacheEngine;
    public function __construct ()
    {
        parent::__construct();

        $this->cacheEngine = Configure::read ('CacheDbAcl.cache');

        if ( ! $this->cacheEngine )
            $this->cacheEngine = 'default';
    }

    public function check($aro, $aco, $action = "*")
    {
        $cacheKey = 'acl.' . md5(igbinary_serialize ($aro) . igbinary_serialize($aco) . $action);

        if ( ! Configure::read('Cache.disable') )
        {
            if ( ($cache = Cache::read ($cacheKey, $this->cacheEngine)) !== FALSE)
                return $cache;
        }

        $result = parent::check ($aro, $aco, $action);
        Cache::write ($cacheKey, $result, $this->cacheEngine);

        return $result;
    }
}