001    /*
002     * Copyright (c) 2007-2014 Concurrent, Inc. All Rights Reserved.
003     *
004     * Project and contact information: http://www.cascading.org/
005     *
006     * This file is part of the Cascading project.
007     *
008     * Licensed under the Apache License, Version 2.0 (the "License");
009     * you may not use this file except in compliance with the License.
010     * You may obtain a copy of the License at
011     *
012     *     http://www.apache.org/licenses/LICENSE-2.0
013     *
014     * Unless required by applicable law or agreed to in writing, software
015     * distributed under the License is distributed on an "AS IS" BASIS,
016     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017     * See the License for the specific language governing permissions and
018     * limitations under the License.
019     */
020    
021    package cascading.pipe;
022    
023    import java.beans.ConstructorProperties;
024    
025    /**
026     * The Merge Pipe allows for multiple branches, with the same fields to be spliced back into a single stream.
027     * <p/>
028     * The behavior is similar to the {@link GroupBy} merging features, but Merge does not perform any grouping or
029     * sorting on keys. Thus, when using a MapReduce platform, no Reducer is required.
030     * <p/>
031     * Merge is non-blocking and performs no processing. Any number of branches and merges may be performed in a
032     * {@link cascading.flow.Flow} without triggering any additional MapReduce jobs on the Hadoop platform.
033     * <p/>
034     * Unlike {@link HashJoin}, no preference need be made for left-hand or right-hand sided-ness of streams in relation
035     * to their sizes.
036     *
037     * @see GroupBy
038     */
039    public class Merge extends Splice
040      {
041      /**
042       * Constructor Merge creates a new Merge instance.
043       *
044       * @param pipes
045       */
046      @ConstructorProperties({"pipes"})
047      public Merge( Pipe... pipes )
048        {
049        super( null, pipes );
050        }
051    
052      /**
053       * Constructor Merge creates a new Merge instance.
054       *
055       * @param name
056       * @param pipes
057       */
058      @ConstructorProperties({"name", "pipes"})
059      public Merge( String name, Pipe... pipes )
060        {
061        super( name, pipes );
062        }
063      }