org.apache.giraph.combiner

Class MinMessageCombiner<I extends org.apache.hadoop.io.WritableComparable,M extends org.apache.hadoop.io.Writable>

java.lang.Object

org.apache.giraph.combiner.MinMessageCombiner<I,M>

Type Parameters:

I - Vertex id

M - Message

All Implemented Interfaces:

MessageCombiner<I,M>

public class MinMessageCombiner<I extends org.apache.hadoop.io.WritableComparable,M extends org.apache.hadoop.io.Writable>
extends Object
implements MessageCombiner<I,M>

Keeps only the message with minimum value.

Constructor Summary

Constructors

Constructor and Description
MinMessageCombiner(NumericTypeOps<M> numTypeOps) Combiner

Method Summary

Modifier and Type	Method and Description
void	combine(I vertexId, M originalMessage, M messageToCombine) Combine messageToCombine with originalMessage, by modifying originalMessage.
M	createInitialMessage() Get the initial message.

Methods inherited from class java.lang.Object

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

Constructor Detail

MinMessageCombiner

public MinMessageCombiner(NumericTypeOps<M> numTypeOps)

Combiner

Parameters:

numTypeOps - Type ops to use

Method Detail

combine

public void combine(I vertexId,
                    M originalMessage,
                    M messageToCombine)

Description copied from interface: MessageCombiner

Combine messageToCombine with originalMessage, by modifying originalMessage. Note that the messageToCombine object may be reused by the infrastructure, therefore, you cannot directly use it or any objects from it in original message

Specified by:

combine in interface MessageCombiner<I extends org.apache.hadoop.io.WritableComparable,M extends org.apache.hadoop.io.Writable>

Parameters:

vertexId - Index of the vertex getting these messages

originalMessage - The first message which we want to combine; put the result of combining in this message

messageToCombine - The second message which we want to combine (object may be reused - do not reference it or its member objects)

createInitialMessage

public M createInitialMessage()

Description copied from interface: MessageCombiner

Get the initial message. When combined with any other message M, the result should be M.

Specified by:

createInitialMessage in interface MessageCombiner<I extends org.apache.hadoop.io.WritableComparable,M extends org.apache.hadoop.io.Writable>

Returns:

Initial message