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 */
018
019package org.apache.hadoop.mapred.lib;
020
021import java.io.IOException;
022
023import org.apache.hadoop.classification.InterfaceAudience;
024import org.apache.hadoop.classification.InterfaceStability;
025import org.apache.hadoop.conf.Configuration;
026import org.apache.hadoop.mapred.InputSplit;
027import org.apache.hadoop.mapred.JobConf;
028import org.apache.hadoop.mapred.RecordReader;
029import org.apache.hadoop.mapred.Reporter;
030import org.apache.hadoop.mapred.SequenceFileInputFormat;
031
032/**
033 * Input format that is a <code>CombineFileInputFormat</code>-equivalent for
034 * <code>SequenceFileInputFormat</code>.
035 *
036 * @see CombineFileInputFormat
037 */
038@InterfaceAudience.Public
039@InterfaceStability.Stable
040public class CombineSequenceFileInputFormat<K,V>
041  extends CombineFileInputFormat<K,V> {
042  @SuppressWarnings({ "rawtypes", "unchecked" })
043  public RecordReader<K,V> getRecordReader(InputSplit split, JobConf conf,
044    Reporter reporter) throws IOException {
045    return new CombineFileRecordReader(conf, (CombineFileSplit)split, reporter,
046      SequenceFileRecordReaderWrapper.class);
047  }
048
049  /**
050   * A record reader that may be passed to <code>CombineFileRecordReader</code>
051   * so that it can be used in a <code>CombineFileInputFormat</code>-equivalent
052   * for <code>SequenceFileInputFormat</code>.
053   *
054   * @see CombineFileRecordReader
055   * @see CombineFileInputFormat
056   * @see SequenceFileInputFormat
057   */
058  private static class SequenceFileRecordReaderWrapper<K,V>
059    extends CombineFileRecordReaderWrapper<K,V> {
060    // this constructor signature is required by CombineFileRecordReader
061    public SequenceFileRecordReaderWrapper(CombineFileSplit split,
062      Configuration conf, Reporter reporter, Integer idx) throws IOException {
063      super(new SequenceFileInputFormat<K,V>(), split, conf, reporter, idx);
064    }
065  }
066}