/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Middleware LLC.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program 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 distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 *
 */
package org.hibernate.transform;
import java.util.List;

Much like RootEntityResultTransformer, but we also distinct the entity in the final result. 
 Since this transformer is stateless, all instances would be considered equal. So for optimization purposes we limit it to a single, singleton instance. 
Author:
Gavin King, Steve Ebersole/**
 * Much like {@link RootEntityResultTransformer}, but we also distinct
 * the entity in the final result.
 * <p/>
 * Since this transformer is stateless, all instances would be considered equal.
 * So for optimization purposes we limit it to a single, singleton {@link #INSTANCE instance}.
 *
 * @author Gavin King
 * @author Steve Ebersole
 */
public class DistinctRootEntityResultTransformer implements TupleSubsetResultTransformer {

	public static final DistinctRootEntityResultTransformer INSTANCE = new DistinctRootEntityResultTransformer();

	
Disallow instantiation of DistinctRootEntityResultTransformer.
/**
	 * Disallow instantiation of DistinctRootEntityResultTransformer.
	 */
	private DistinctRootEntityResultTransformer() {
	}

	
Simply delegates to RootEntityResultTransformer.transformTuple. 
Params:
tuple – The tuple to transform
aliases – The tuple aliases
Returns:
The transformed tuple row./**
	 * Simply delegates to {@link RootEntityResultTransformer#transformTuple}.
	 *
	 * @param tuple The tuple to transform
	 * @param aliases The tuple aliases
	 * @return The transformed tuple row.
	 */
	@Override
	public Object transformTuple(Object[] tuple, String[] aliases) {
		return RootEntityResultTransformer.INSTANCE.transformTuple( tuple, aliases );
	}

	
Simply delegates to DistinctResultTransformer.transformList. 
Params:
list – The list to transform.
Returns:
The transformed List./**
	 * Simply delegates to {@link DistinctResultTransformer#transformList}.
	 *
	 * @param list The list to transform.
	 * @return The transformed List.
	 */
	@Override
	public List transformList(List list) {
		return DistinctResultTransformer.INSTANCE.transformList( list );
	}

	@Override
	public boolean[] includeInTransform(String[] aliases, int tupleLength) {
		return RootEntityResultTransformer.INSTANCE.includeInTransform( aliases, tupleLength );
	}

	@Override
	public boolean isTransformedValueATupleElement(String[] aliases, int tupleLength) {
		return RootEntityResultTransformer.INSTANCE.isTransformedValueATupleElement( null, tupleLength );
	}

	
Serialization hook for ensuring singleton uniqueing.
Returns:
The singleton instance : INSTANCE/**
	 * Serialization hook for ensuring singleton uniqueing.
	 *
	 * @return The singleton instance : {@link #INSTANCE}
	 */
	private Object readResolve() {
		return INSTANCE;
	}

}