001/* An actor for the Reduce DDP pattern.
002 * 
003 * Copyright (c) 2011-2012 The Regents of the University of California.
004 * All rights reserved.
005 *
006 * '$Author: jianwu $'
007 * '$Date: 2013-02-15 21:11:35 +0000 (Fri, 15 Feb 2013) $' 
008 * '$Revision: 31450 $'
009 * 
010 * Permission is hereby granted, without written agreement and without
011 * license or royalty fees, to use, copy, modify, and distribute this
012 * software and its documentation for any purpose, provided that the above
013 * copyright notice and the following two paragraphs appear in all copies
014 * of this software.
015 *
016 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
017 * FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
018 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
019 * THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
020 * SUCH DAMAGE.
021 *
022 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
023 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
024 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
025 * PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
026 * CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
027 * ENHANCEMENTS, OR MODIFICATIONS.
028 *
029 */
030package org.kepler.ddp.actor.pattern;
031
032import ptolemy.data.BooleanToken;
033import ptolemy.data.expr.Parameter;
034import ptolemy.data.expr.StringParameter;
035import ptolemy.data.type.BaseType;
036import ptolemy.kernel.CompositeEntity;
037import ptolemy.kernel.util.IllegalActionException;
038import ptolemy.kernel.util.NameDuplicationException;
039import ptolemy.kernel.util.Workspace;
040
041/** An actor for the Reduce DDP pattern. This actor reads one
042 *  input data set of key-value pairs. The sub-workflow in 
043 *  this actor needs to be completed by reading data 
044 *  from the output ports of the ReduceInput actor and sending
045 *  key-value pairs (an array of <key, value> records) to the 
046 *  ReduceOutput actor. For each unique key, the sub-workflow
047 *  is executed once with the key and all the values associated
048 *  with that key.
049 * 
050 *  @author Daniel Crawl
051 *  @version $Id: Reduce.java 31450 2013-02-15 21:11:35Z jianwu $
052 */
053public class Reduce extends SingleInputPatternActor {
054
055    /** Construct a new Reduce in a container with a given name. */
056    public Reduce(CompositeEntity container, String name)
057            throws IllegalActionException, NameDuplicationException {
058        super(container, name);
059        
060        useAsCombiner = new Parameter(this, "useAsCombiner");
061        useAsCombiner.setTypeEquals(BaseType.BOOLEAN);
062        useAsCombiner.setToken(BooleanToken.FALSE);
063        
064        combineExecutionClass = new StringParameter(this, "combineExecutionClass");
065        
066        groupingComparatorClass = new StringParameter(this, "groupingComparatorClass");
067
068    }
069
070    /** Construct a new Reduce in a workspace. */
071    public Reduce(Workspace workspace) {
072        super(workspace);
073    }
074
075    /** If true, use the sub-workflow or execution class to pre-reduce the
076     *  data.
077     */
078    public Parameter useAsCombiner;
079    
080    /** The name of the combiner class. */
081    public StringParameter combineExecutionClass;
082    
083    /** The name of the GroupingComparatorClass, used only in hadoop for group input data of reducers. */
084    public StringParameter groupingComparatorClass;
085}