001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.mapred;
019
020import java.io.IOException;
021import java.util.Iterator;
022import org.apache.hadoop.hbase.client.Put;
023import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
024import org.apache.hadoop.mapred.MapReduceBase;
025import org.apache.hadoop.mapred.OutputCollector;
026import org.apache.hadoop.mapred.Reporter;
027import org.apache.yetus.audience.InterfaceAudience;
028import org.slf4j.Logger;
029import org.slf4j.LoggerFactory;
030
031/**
032 * Write to table each key, record pair
033 */
034@InterfaceAudience.Public
035public class IdentityTableReduce extends MapReduceBase
036  implements TableReduce<ImmutableBytesWritable, Put> {
037  @SuppressWarnings("unused")
038  private static final Logger LOG = LoggerFactory.getLogger(IdentityTableReduce.class.getName());
039
040  /**
041   * No aggregation, output pairs of (key, record) nnnnn
042   */
043  public void reduce(ImmutableBytesWritable key, Iterator<Put> values,
044    OutputCollector<ImmutableBytesWritable, Put> output, Reporter reporter) throws IOException {
045
046    while (values.hasNext()) {
047      output.collect(key, values.next());
048    }
049  }
050}