edu.rice.hj.runtime.mapreduce

Class MapReduce<K,V>

java.lang.Object

edu.rice.hj.runtime.mapreduce.MapReduce<K,V>

public abstract class MapReduce<K,V>
extends Object

Abstract MapReduce class.

Author:

Shams Imam (shams@rice.edu)

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<K,V>[]	_final
protected Map<K,List<V>>[][]	_intermediate
protected int	_numMapTasks
protected int	_numReduceTasks
protected Map<K,V>	_result

Constructor Summary

Constructors

Constructor and Description
MapReduce(int numMapTasks, int numReduceTasks) Constructor for MapReduce.

Method Summary

Modifier and Type	Method and Description
void	emitFinal(int reduceTaskId, K key, V val) emitFinal.
void	emitIntermediate(int mapTaskId, K key, V val) emitIntermediate.
Set<K>	getKeys() getKeys.
Map<K,V>	getResult() getResult.
void	merge() merge.
V	query(K key) query.
void	reduce(int reduceTaskId) reduce.
V	reduce(List<V> vals) reduce.
abstract V	reduce(V v1, V v2) reduce.
void	run() run.
abstract MapTask<K,V>	splitter(int taskId) splitter.

Methods inherited from class java.lang.Object

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

Field Detail

_numMapTasks

protected int _numMapTasks

_numReduceTasks

protected int _numReduceTasks

_intermediate

protected Map<K,List<V>>[][] _intermediate

_final

protected Map<K,V>[] _final

_result

protected Map<K,V> _result

Constructor Detail

MapReduce

public MapReduce(int numMapTasks,
                 int numReduceTasks)

Constructor for MapReduce.

Parameters:

numMapTasks - a int.

numReduceTasks - a int.

Method Detail

emitIntermediate

public void emitIntermediate(int mapTaskId,
                             K key,
                             V val)

emitIntermediate.

Parameters:

mapTaskId - a int.

key - a K object.

val - a V object.

getResult

public Map<K,V> getResult()

getResult.

Returns:

a Map object.

getKeys

public Set<K> getKeys()

getKeys.

Returns:

a Set object.

query

public V query(K key)

query.

Parameters:

key - a K object.

Returns:

a V object.

run

public void run()
         throws SuspendableException

run.

Throws:

SuspendableException

splitter

public abstract MapTask<K,V> splitter(int taskId)

splitter.

Parameters:

taskId - a int.

Returns:

a MapTask object.

reduce

public void reduce(int reduceTaskId)

reduce.

Parameters:

reduceTaskId - a int.

merge

public void merge()

merge.

reduce

public V reduce(List<V> vals)

reduce.

Parameters:

vals - a List object.

Returns:

a V object.

emitFinal

public void emitFinal(int reduceTaskId,
                      K key,
                      V val)

emitFinal.

Parameters:

reduceTaskId - a int.

key - a K object.

val - a V object.

reduce

public abstract V reduce(V v1,
                         V v2)

reduce.

Parameters:

v1 - a V object.

v2 - a V object.

Returns:

a V object.