/***********************************************************************************************************************
 *
 * Copyright (C) 2010 by the Stratosphere project (http://stratosphere.eu)
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 *
 **********************************************************************************************************************/

package eu.stratosphere.pact.runtime.sort;

/**
 * @author Erik Nijkamp
 */
public interface IndexedSortable {

	/**
	 * Compare items at the given addresses consistent with the semantics of
	 * {@link java.util.Comparator#compare(Object, Object)}.
	 */
	int compare(int i, int j);

	/**
	 * Swap items at the given addresses.
	 */
	void swap(int i, int j);

	/**
	 * Gets the number of elements in the sortable.
	 * 
	 * @return The number of elements.
	 */
	int size();

}
