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.fs.FileSystem;
026import org.apache.hadoop.fs.Path;
027import org.apache.hadoop.io.Text;
028import org.apache.hadoop.io.compress.CompressionCodec;
029import org.apache.hadoop.io.compress.CompressionCodecFactory;
030import org.apache.hadoop.io.compress.SplittableCompressionCodec;
031
032/**
033 * An {@link InputFormat} for plain text files. Files are broken into lines.
034 * Either linefeed or carriage-return are used to signal end of line. Each line
035 * is divided into key and value parts by a separator byte. If no such a byte
036 * exists, the key will be the entire line and value will be empty.
037 */
038@InterfaceAudience.Public
039@InterfaceStability.Stable
040public class KeyValueTextInputFormat extends FileInputFormat<Text, Text>
041  implements JobConfigurable {
042
043  private CompressionCodecFactory compressionCodecs = null;
044  
045  public void configure(JobConf conf) {
046    compressionCodecs = new CompressionCodecFactory(conf);
047  }
048  
049  protected boolean isSplitable(FileSystem fs, Path file) {
050    final CompressionCodec codec = compressionCodecs.getCodec(file);
051    if (null == codec) {
052      return true;
053    }
054    return codec instanceof SplittableCompressionCodec;
055  }
056  
057  public RecordReader<Text, Text> getRecordReader(InputSplit genericSplit,
058                                                  JobConf job,
059                                                  Reporter reporter)
060    throws IOException {
061    
062    reporter.setStatus(genericSplit.toString());
063    return new KeyValueLineRecordReader(job, (FileSplit) genericSplit);
064  }
065
066}