org.apache.flink.runtime.operators.shipping

Class OutputEmitter<T>

java.lang.Object

org.apache.flink.runtime.operators.shipping.OutputEmitter<T>

Type Parameters:

T - The type of the element handled by the emitter.

All Implemented Interfaces:

ChannelSelector<SerializationDelegate<T>>

public class OutputEmitter<T>
extends Object
implements ChannelSelector<SerializationDelegate<T>>

The output emitter decides to which of the possibly multiple output channels a record is sent. It implement routing based on hash-partitioning, broadcasting, round-robin, custom partition functions, etc.

Constructor Summary

Constructors

Constructor and Description
OutputEmitter(ShipStrategyType strategy, int indexInSubtaskGroup) Creates a new channel selector that uses the given strategy (broadcasting, partitioning, ...) and uses the supplied task index perform a round robin distribution.
OutputEmitter(ShipStrategyType strategy, int indexInSubtaskGroup, TypeComparator<T> comparator, Partitioner<?> partitioner, DataDistribution distribution)
OutputEmitter(ShipStrategyType strategy, TypeComparator<T> comparator) Creates a new channel selector that uses the given strategy (broadcasting, partitioning, ...) and uses the supplied comparator to hash / compare records for partitioning them deterministically.

Method Summary

Modifier and Type	Method and Description
int[]	selectChannels(SerializationDelegate<T> record, int numberOfChannels) Returns the logical channel indexes, to which the given record should be written.

Methods inherited from class java.lang.Object

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

Constructor Detail

OutputEmitter

public OutputEmitter(ShipStrategyType strategy,
                     int indexInSubtaskGroup)

Creates a new channel selector that uses the given strategy (broadcasting, partitioning, ...) and uses the supplied task index perform a round robin distribution.

Parameters:

strategy - The distribution strategy to be used.

OutputEmitter

public OutputEmitter(ShipStrategyType strategy,
                     TypeComparator<T> comparator)

Creates a new channel selector that uses the given strategy (broadcasting, partitioning, ...) and uses the supplied comparator to hash / compare records for partitioning them deterministically.

Parameters:

strategy - The distribution strategy to be used.

comparator - The comparator used to hash / compare the records.

OutputEmitter

public OutputEmitter(ShipStrategyType strategy,
                     int indexInSubtaskGroup,
                     TypeComparator<T> comparator,
                     Partitioner<?> partitioner,
                     DataDistribution distribution)

Method Detail

selectChannels

public final int[] selectChannels(SerializationDelegate<T> record,
                                  int numberOfChannels)

Description copied from interface: ChannelSelector

Returns the logical channel indexes, to which the given record should be written.

Specified by:

selectChannels in interface ChannelSelector<SerializationDelegate<T>>

Parameters:

record - the record to the determine the output channels for

numberOfChannels - the total number of output channels which are attached to respective output gate

Returns:

a (possibly empty) array of integer numbers which indicate the indices of the output channels through which the record shall be forwarded