/* XXL: The eXtensible and fleXible Library for data processing

Copyright (C) 2000-2011 Prof. Dr. Bernhard Seeger
                        Head of the Database Research Group
                        Department of Mathematics and Computer Science
                        University of Marburg
                        Germany

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library;  If not, see <http://www.gnu.org/licenses/>. 

    http://code.google.com/p/xxl/

*/

package xxl.core.io.converters;

import java.io.DataOutputStream;
import java.io.IOException;

import xxl.core.io.CounterOutputStream;
import xxl.core.io.NullOutputStream;
import xxl.core.util.WrappingRuntimeException;

/**
 * This abstract class represents a special kind of converter which provides a
 * method which returns the size of an object in bytes before doing the
 * serialization.
 *
 * @param <T> the type of the object that can be converted by using this
 *        converter.
 * @see Converter
 */
public abstract class SizeConverter<T> extends Converter<T> {

	/**
	 * Returns the number of bytes used for serialization/deserialization of a
	 * special object. This method should be overwritten to become performant.
	 * 
	 * @param object the object of which the size is returned.
	 * @return the number of bytes.
	 */
	public int getSerializedSize(T object) {
		try {
			CounterOutputStream dOut = new CounterOutputStream(NullOutputStream.NULL);
			write(new DataOutputStream(dOut), object);
			return (int)dOut.getCounter();
		}
		catch (IOException e) {
			throw new WrappingRuntimeException(e);
		}
	}
}