org.apache.hadoop.examples
Class MultiFileWordCount.CombineFileLineRecordReader

java.lang.Object
  extended by org.apache.hadoop.mapreduce.RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>
      extended by org.apache.hadoop.examples.MultiFileWordCount.CombineFileLineRecordReader
All Implemented Interfaces:
Closeable
Enclosing class:
MultiFileWordCount

public static class MultiFileWordCount.CombineFileLineRecordReader
extends RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>

RecordReader is responsible from extracting records from a chunk of the CombineFileSplit.


Constructor Summary
MultiFileWordCount.CombineFileLineRecordReader(CombineFileSplit split, TaskAttemptContext context, Integer index)
           
 
Method Summary
 void close()
          Close the record reader.
 MultiFileWordCount.WordOffset getCurrentKey()
          Get the current key
 org.apache.hadoop.io.Text getCurrentValue()
          Get the current value.
 float getProgress()
          The current progress of the record reader through its data.
 void initialize(InputSplit split, TaskAttemptContext context)
          Called once at initialization.
 boolean nextKeyValue()
          Read the next key, value pair.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

MultiFileWordCount.CombineFileLineRecordReader

public MultiFileWordCount.CombineFileLineRecordReader(CombineFileSplit split,
                                                      TaskAttemptContext context,
                                                      Integer index)
                                               throws IOException
Throws:
IOException
Method Detail

initialize

public void initialize(InputSplit split,
                       TaskAttemptContext context)
                throws IOException,
                       InterruptedException
Description copied from class: RecordReader
Called once at initialization.

Specified by:
initialize in class RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>
Parameters:
split - the split that defines the range of records to read
context - the information about the task
Throws:
IOException
InterruptedException

close

public void close()
           throws IOException
Description copied from class: RecordReader
Close the record reader.

Specified by:
close in interface Closeable
Specified by:
close in class RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>
Throws:
IOException

getProgress

public float getProgress()
                  throws IOException
Description copied from class: RecordReader
The current progress of the record reader through its data.

Specified by:
getProgress in class RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>
Returns:
a number between 0.0 and 1.0 that is the fraction of the data read
Throws:
IOException

nextKeyValue

public boolean nextKeyValue()
                     throws IOException
Description copied from class: RecordReader
Read the next key, value pair.

Specified by:
nextKeyValue in class RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>
Returns:
true if a key/value pair was read
Throws:
IOException

getCurrentKey

public MultiFileWordCount.WordOffset getCurrentKey()
                                            throws IOException,
                                                   InterruptedException
Description copied from class: RecordReader
Get the current key

Specified by:
getCurrentKey in class RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>
Returns:
the current key or null if there is no current key
Throws:
IOException
InterruptedException

getCurrentValue

public org.apache.hadoop.io.Text getCurrentValue()
                                          throws IOException,
                                                 InterruptedException
Description copied from class: RecordReader
Get the current value.

Specified by:
getCurrentValue in class RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>
Returns:
the object that was read
Throws:
IOException
InterruptedException


Copyright © 2009 The Apache Software Foundation