org.apache.flink.graph.gsa

Class ApplyFunction<K,VV,M>

java.lang.Object

org.apache.flink.graph.gsa.ApplyFunction<K,VV,M>

Type Parameters:

K - the vertex ID type

VV - the vertex value type

M - the input type (produced by the Sum phase)

All Implemented Interfaces:

Serializable

public abstract class ApplyFunction<K,VV,M>
extends Object
implements Serializable

The base class for the third and last step of a GatherSumApplyIteration.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ApplyFunction()

Method Summary

Modifier and Type	Method and Description
abstract void	apply(M newValue, VV currentValue) This method is invoked once per superstep, after the SumFunction in a GatherSumApplyIteration.
<T> Collection<T>	getBroadcastSet(String name) Gets the broadcast data set registered under the given name.
<T extends Aggregator<?>> T	getIterationAggregator(String name) Gets the iteration aggregator registered under the given name.
long	getNumberOfVertices() Retrieves the number of vertices in the graph.
<T extends Value> T	getPreviousIterationAggregate(String name) Get the aggregated value that an aggregator computed in the previous iteration.
int	getSuperstepNumber() Gets the number of the superstep, starting at 1.
void	init(IterationRuntimeContext iterationRuntimeContext)
void	postSuperstep() This method is executed once per superstep after the vertex update function has been invoked for each vertex.
void	preSuperstep() This method is executed once per superstep before the vertex update function is invoked for each vertex.
void	setOutput(Vertex<K,VV> vertex, Collector<Vertex<K,VV>> out)
void	setResult(VV result) Sets the result for the apply function.

Methods inherited from class java.lang.Object

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

Constructor Detail

ApplyFunction

public ApplyFunction()

Method Detail

getNumberOfVertices

public long getNumberOfVertices()

Retrieves the number of vertices in the graph.

Returns:

the number of vertices if the IterationConfiguration.setOptNumVertices(boolean) option has been set; -1 otherwise.

apply

public abstract void apply(M newValue,
                           VV currentValue)

This method is invoked once per superstep, after the SumFunction in a GatherSumApplyIteration. It updates the Vertex values.

Parameters:

newValue - the value computed during the current superstep.

currentValue - the current Vertex value.

setResult

public void setResult(VV result)

Sets the result for the apply function.

Parameters:

result - the result of the apply phase

preSuperstep

public void preSuperstep()

This method is executed once per superstep before the vertex update function is invoked for each vertex.

postSuperstep

public void postSuperstep()

This method is executed once per superstep after the vertex update function has been invoked for each vertex.

getSuperstepNumber

public int getSuperstepNumber()

Gets the number of the superstep, starting at 1.

Returns:

The number of the current superstep.

getIterationAggregator

public <T extends Aggregator<?>> T getIterationAggregator(String name)

Gets the iteration aggregator registered under the given name. The iteration aggregator combines all aggregates globally once per superstep and makes them available in the next superstep.

Parameters:

name - The name of the aggregator.

Returns:

The aggregator registered under this name, or null, if no aggregator was registered.

getPreviousIterationAggregate

public <T extends Value> T getPreviousIterationAggregate(String name)

Get the aggregated value that an aggregator computed in the previous iteration.

Parameters:

name - The name of the aggregator.

Returns:

The aggregated value of the previous iteration.

getBroadcastSet

public <T> Collection<T> getBroadcastSet(String name)

Gets the broadcast data set registered under the given name. Broadcast data sets are available on all parallel instances of a function.

Parameters:

name - The name under which the broadcast set is registered.

Returns:

The broadcast data set.

init

public void init(IterationRuntimeContext iterationRuntimeContext)

setOutput

public void setOutput(Vertex<K,VV> vertex,
                      Collector<Vertex<K,VV>> out)