AbstractOutputTuple.java

/*
 * #!
 * %
 * Copyright (C) 2014 - 2016 Humboldt-Universität zu Berlin
 * %
 * 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 de.hub.cs.dbis.lrb.types;

/**
 * The base class for all LRB output tuples (including intermediate result tuples).<br />
 * <br />
 * All output tuples do have the following attributes: TYPE, TIME, EMIT
 * <ul>
 * <li>TYPE: the tuple type ID</li>
 * <li>TIME: 'the timestamp of the input tuple that triggered the tuple to be generated' (in LRB seconds)</li>
 * <li>EMIT: 'the timestamp immediately prior to emitting the tuple' (in LRB seconds)</li>
 * </ul>
 * 
 * @author mjsax
 */
public abstract class AbstractOutputTuple extends AbstractLRBTuple {
	private static final long serialVersionUID = 6525749728643815820L;
	
	// attribute indexes
	/** The index of the EMIT attribute. */
	public final static int EMIT_IDX = 2;
	
	
	
	protected AbstractOutputTuple() {
		super();
	}
	
	protected AbstractOutputTuple(Short type, Short time, Short emit) {
		super(type, time);
		
		assert (emit != null);
		assert (emit.longValue() >= time.longValue());
		super.add(EMIT_IDX, emit);
		
		assert (super.size() == 3);
	}
	
	
	
	/**
	 * Returns the emit timestamp (in LRB seconds) of this {@link AbstractOutputTuple}.
	 * 
	 * @return the emit timestamp of this tuple
	 */
	public final Short getEmit() {
		return (Short)super.get(EMIT_IDX);
	}
	
}