001/*
002 * Copyright (c) 2007-2016 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
021package cascading.pipe;
022
023import 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 */
039public 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  }