/***********************************************************************************************************************
 *
 * Copyright (C) 2012 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.task;

/**
 * Enumeration for the different dam behaviors of an algorithm or a driver
 * strategy. The dam behavior describes whether records pass through the
 * algorithm (no dam), whether all records are collected before the first
 * is returned (full dam) or whether a certain large amount is collected before
 * the algorithm returns records. 
 */
public enum DamBehavior {
	
	/**
	 * Constant indicating that the algorithm does not come with any form of dam
	 * and records pass through in a pipelined fashion.
	 */
	PIPELINED,
	
	/**
	 * Constant indicating that the algorithm materialized (some) records, but may
	 * return records before all records are read.
	 */
	MATERIALIZING,
	
	/**
	 * Constant indicating that the algorithm collects all records before returning any.
	 */
	FULL_DAM;
	
	/**
	 * Checks whether this enumeration represents some form of materialization,
	 * either with a full dam or without.
	 * 
	 * @return True, if this enumeration constant represents a materializing behavior,
	 *         false otherwise.
	 */
	public boolean isMaterializing() {
		return this != PIPELINED;
	}
}
