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;
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.io.Text;
027import org.apache.hadoop.io.Writable;
028import org.apache.hadoop.io.WritableComparable;
029
030/**
031 * This class converts the input keys and values to their String forms by calling toString()
032 * method. This class to SequenceFileAsTextInputFormat class is as LineRecordReader
033 * class to TextInputFormat class.
034 */
035@InterfaceAudience.Public
036@InterfaceStability.Stable
037public class SequenceFileAsTextRecordReader
038  implements RecordReader<Text, Text> {
039  
040  private final SequenceFileRecordReader<WritableComparable, Writable>
041  sequenceFileRecordReader;
042
043  private WritableComparable innerKey;
044  private Writable innerValue;
045
046  public SequenceFileAsTextRecordReader(Configuration conf, FileSplit split)
047    throws IOException {
048    sequenceFileRecordReader =
049      new SequenceFileRecordReader<WritableComparable, Writable>(conf, split);
050    innerKey = sequenceFileRecordReader.createKey();
051    innerValue = sequenceFileRecordReader.createValue();
052  }
053
054  public Text createKey() {
055    return new Text();
056  }
057  
058  public Text createValue() {
059    return new Text();
060  }
061
062  /** Read key/value pair in a line. */
063  public synchronized boolean next(Text key, Text value) throws IOException {
064    Text tKey = key;
065    Text tValue = value;
066    if (!sequenceFileRecordReader.next(innerKey, innerValue)) {
067      return false;
068    }
069    tKey.set(innerKey.toString());
070    tValue.set(innerValue.toString());
071    return true;
072  }
073  
074  public float getProgress() throws IOException {
075    return sequenceFileRecordReader.getProgress();
076  }
077  
078  public synchronized long getPos() throws IOException {
079    return sequenceFileRecordReader.getPos();
080  }
081  
082  public synchronized void close() throws IOException {
083    sequenceFileRecordReader.close();
084  }
085  
086}