class Config
{
    private static $config = null;
    private $host = 'localhost';
    private $userName = 'root';
    private $password = '';
    private $database = 'keep_lab';
    private $lcTimeNames = 'ru_RU';
    private $encoding = 'utf8';
    public static function getConfig()
    {
        if (self::$config === null) {
            self::$config = new self;
        }
        return self::$config;
    }
}

public static function getDB()
{
    if (self::$db === null) {
        self::$db = new self(Config::getConfig());
    }
    return self::$db;
}