org.apache.flink.graph.gsa

Class SumFunction<VV,EV,M>

java.lang.Object

org.apache.flink.graph.gsa.SumFunction<VV,EV,M>

Type Parameters:

VV - the vertex value type

EV - the edge value type

M - the output type

All Implemented Interfaces:

Serializable

public abstract class SumFunction<VV,EV,M>
extends Object
implements Serializable

The base class for the second step of a GatherSumApplyIteration.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SumFunction()

Method Summary

Modifier and Type	Method and Description
<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.
abstract M	sum(M arg0, M arg1) This method is invoked once per superstep, after the GatherFunction in a GatherSumApplyIteration.

Methods inherited from class java.lang.Object

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

Constructor Detail

SumFunction

public SumFunction()

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.

sum

public abstract M sum(M arg0,
                      M arg1)

This method is invoked once per superstep, after the GatherFunction in a GatherSumApplyIteration. It combines the partial values produced by GatherFunction.gather(Neighbor) in pairs, until a single value has been computed.

Parameters:

arg0 - the first partial value.

arg1 - the second partial value.

Returns:

the combined value.

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)