PHP关键字过滤的函数

    /**
     * 关键字过滤
     */
    function keyfilter($content){
        $config = Config::get('memcache.1700');    
        $this->memcache = new \Memcache;
        $this->memcache->connect($config['host'], $config['port']);
        
        $data = $this->memcache->get('keyfilter');
        if ($data)
            $data = json_decode($data, true);
        
        if (empty($data)) {
            $result = Db::table('web_badkeys')->where("status = 1")->select();
            foreach ($result AS $key => $val) {
                $data[] = '/'.$val['title'].'/';        
            }
            $this->memcache->set('keyfilter', json_encode($data));
        }
        $content = preg_replace($data, '**', $content);
        return $content;
    }