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.mapred.lib;
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.conf.Configuration;
026    import org.apache.hadoop.mapred.InputSplit;
027    import org.apache.hadoop.mapred.JobConf;
028    import org.apache.hadoop.mapred.RecordReader;
029    import org.apache.hadoop.mapred.Reporter;
030    import 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
040    public 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    }