Something

<?php

class DBEngine 
{
	static $subengine;

	public function connect( $dsn )
	{
		list( $dsn_type, $dsn_string ) = explode( ':', $dsn, 2 );
	
		include(Site::get_dir('habari') . '/system/schema/' . $dsn_type . '/dbengine.php');

		self::$subengine = new DBSubEngine( $dsn );
	}

	public function check_dsn( $dsn )
	{
		return self::$subengine->check_dsn( $dsn );
	}

}

?>