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