com.asakusafw.runtime.flow

Class SegmentedCombiner<KEY extends SegmentedWritable,VALUE extends SegmentedWritable>

java.lang.Object

org.apache.hadoop.mapreduce.Reducer<KEY,VALUE,KEY,VALUE>

com.asakusafw.runtime.flow.SegmentedCombiner<KEY,VALUE>

Type Parameters:

KEY - the key type

VALUE - the value type

public abstract class SegmentedCombiner<KEY extends SegmentedWritable,VALUE extends SegmentedWritable>
extends org.apache.hadoop.mapreduce.Reducer<KEY,VALUE,KEY,VALUE>

A skeletal implementation of Hadoop Combiner class which uses SegmentedWritable as it key/value.

Since:

0.1.0

Version:

0.5.1

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Reducer

org.apache.hadoop.mapreduce.Reducer.Context

Field Summary

Fields

Modifier and Type	Field and Description
static String	GET_RENDEZVOUS The method name of getRendezvous(SegmentedWritable).

Constructor Summary

Constructors

Constructor and Description
SegmentedCombiner()

Method Summary

Modifier and Type	Method and Description
protected abstract Rendezvous<VALUE>	getRendezvous(KEY key) Returns the Rendezvous object for processing the target segment.
protected void	reduce(KEY key, Iterable<VALUE> values, org.apache.hadoop.mapreduce.Reducer.Context context)

Methods inherited from class org.apache.hadoop.mapreduce.Reducer

cleanup, run, setup

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

GET_RENDEZVOUS

public static final String GET_RENDEZVOUS

The method name of getRendezvous(SegmentedWritable).

See Also:

Constant Field Values

Constructor Detail

SegmentedCombiner

public SegmentedCombiner()

Method Detail

getRendezvous

protected abstract Rendezvous<VALUE> getRendezvous(KEY key)

Returns the Rendezvous object for processing the target segment.

Parameters:

key - the segment information

Returns:

the corresponded Rendezvous object

reduce

protected void reduce(KEY key,
                      Iterable<VALUE> values,
                      org.apache.hadoop.mapreduce.Reducer.Context context)
               throws IOException,
                      InterruptedException

Overrides:

reduce in class org.apache.hadoop.mapreduce.Reducer<KEY extends SegmentedWritable,VALUE extends SegmentedWritable,KEY extends SegmentedWritable,VALUE extends SegmentedWritable>

Throws:

IOException

InterruptedException