Package org.apache.tinkerpop.gremlin.process.computer

Class GraphComputerTest.VertexProgramJ

java.lang.Object

org.apache.tinkerpop.gremlin.process.computer.util.StaticVertexProgram

org.apache.tinkerpop.gremlin.process.computer.GraphComputerTest.VertexProgramJ

All Implemented Interfaces:

Cloneable, VertexProgram

Enclosing class:

GraphComputerTest

public static class GraphComputerTest.VertexProgramJ
extends StaticVertexProgram

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.tinkerpop.gremlin.process.computer.VertexProgram

VertexProgram.Builder, VertexProgram.Features

Field Summary

Fields inherited from interface org.apache.tinkerpop.gremlin.process.computer.VertexProgram

VERTEX_PROGRAM

Constructor Summary

Constructors

Constructor	Description
VertexProgramJ()

Method Summary

Modifier and Type	Method	Description
void	execute(Vertex vertex, Messenger messenger, Memory memory)	This method denotes the main body of the computation and is executed on each vertex in the graph.
Set<MemoryComputeKey>	getMemoryComputeKeys()	The Memory keys that will be used during the computation.
Set<MessageScope>	getMessageScopes(Memory memory)	This method returns all the MessageScope possibilities for a particular iteration of the vertex program.
GraphComputer.Persist	getPreferredPersist()
GraphComputer.ResultGraph	getPreferredResultGraph()
void	setup(Memory memory)	The method is called at the beginning of the computation.
boolean	terminate(Memory memory)	The method is called at the end of each iteration to determine if the computation is complete.
void	workerIterationEnd(Memory memory)	This method is called at the end of each iteration of each "computational chunk." The set of vertices in the graph are typically not processed with full parallelism.
void	workerIterationStart(Memory memory)	This method is called at the start of each iteration of each "computational chunk." The set of vertices in the graph are typically not processed with full parallelism.

Methods inherited from class org.apache.tinkerpop.gremlin.process.computer.util.StaticVertexProgram

clone, storeState

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.tinkerpop.gremlin.process.computer.VertexProgram

getFeatures, getMapReducers, getMessageCombiner, getTraverserRequirements, getVertexComputeKeys, loadState

Constructor Detail

VertexProgramJ

public VertexProgramJ()

Method Detail

setup

public void setup(Memory memory)

Description copied from interface: VertexProgram

The method is called at the beginning of the computation. The method is global to the GraphComputer and as such, is not called for each vertex. During this stage, the Memory should be initialized to to its "start state."

Parameters:

memory - The global memory of the GraphComputer

workerIterationStart

public void workerIterationStart(Memory memory)

Description copied from interface: VertexProgram

This method is called at the start of each iteration of each "computational chunk." The set of vertices in the graph are typically not processed with full parallelism. The vertex set is split into subsets and a worker is assigned to call the VertexProgram.execute(org.apache.tinkerpop.gremlin.structure.Vertex, org.apache.tinkerpop.gremlin.process.computer.Messenger<M>, org.apache.tinkerpop.gremlin.process.computer.Memory) method. The default implementation is a no-op.

Parameters:

memory - The memory at the start of the iteration.

execute

public void execute(Vertex vertex,
                    Messenger messenger,
                    Memory memory)

Description copied from interface: VertexProgram

This method denotes the main body of the computation and is executed on each vertex in the graph. This method is logically executed in parallel on all vertices in the graph. When the Memory is read, it is according to the aggregated state yielded in the previous iteration. When the Memory is written, the data will be aggregated at the end of the iteration for reading in the next iteration.

Parameters:

vertex - the Vertex to execute the VertexProgram on

messenger - the messenger that moves data between vertices

memory - the shared state between all vertices in the computation

terminate

public boolean terminate(Memory memory)

Description copied from interface: VertexProgram

The method is called at the end of each iteration to determine if the computation is complete. The method is global to the GraphComputer and as such, is not called for each Vertex. The Memory maintains the aggregated data from the last execute() iteration.

Parameters:

memory - The global memory of the GraphComputer

Returns:

whether or not to halt the computation

workerIterationEnd

public void workerIterationEnd(Memory memory)

Description copied from interface: VertexProgram

This method is called at the end of each iteration of each "computational chunk." The set of vertices in the graph are typically not processed with full parallelism. The vertex set is split into subsets and a worker is assigned to call the VertexProgram.execute(org.apache.tinkerpop.gremlin.structure.Vertex, org.apache.tinkerpop.gremlin.process.computer.Messenger<M>, org.apache.tinkerpop.gremlin.process.computer.Memory) method. The default implementation is a no-op.

Parameters:

memory - The memory at the end of the iteration.

getMemoryComputeKeys

public Set<MemoryComputeKey> getMemoryComputeKeys()

Description copied from interface: VertexProgram

The Memory keys that will be used during the computation. These are the only keys that can be read or written throughout the life of the GraphComputer. The default is an empty set.

Returns:

the set of memory keys that will be read/written

getMessageScopes

public Set<MessageScope> getMessageScopes(Memory memory)

Description copied from interface: VertexProgram

This method returns all the MessageScope possibilities for a particular iteration of the vertex program. The returned messages scopes are the scopes that will be used to send messages during the stated iteration. It is not a requirement that all stated messages scopes be used, just that it is possible that they be used during the iteration.

Parameters:

memory - an immutable form of the Memory

Returns:

all possible message scopes during said vertex program iteration

getPreferredResultGraph

public GraphComputer.ResultGraph getPreferredResultGraph()

getPreferredPersist

public GraphComputer.Persist getPreferredPersist()