org.apache.tinkerpop.gremlin.process.computer.clone

Class CloneVertexProgram

java.lang.Object

org.apache.tinkerpop.gremlin.process.computer.clone.CloneVertexProgram

All Implemented Interfaces:

Cloneable, VertexProgram<org.javatuples.Tuple>

public class CloneVertexProgram
extends Object
implements VertexProgram<org.javatuples.Tuple>

Author:

Daniel Kuppitz (http://gremlin.guru)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CloneVertexProgram.Builder

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

VertexProgram.Features

Field Summary

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

VERTEX_PROGRAM

Method Summary

Modifier and Type	Method and Description
static CloneVertexProgram.Builder	build()
VertexProgram<org.javatuples.Tuple>	clone() When multiple workers on a single machine need VertexProgram instances, it is possible to use clone.
void	execute(Vertex sourceVertex, Messenger<org.javatuples.Tuple> messenger, Memory memory) This method denotes the main body of the computation and is executed on each vertex in the graph.
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.
String	toString()

Methods inherited from class java.lang.Object

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

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

createVertexProgram, getFeatures, getMapReducers, getMemoryComputeKeys, getMessageCombiner, getTraverserRequirements, getVertexComputeKeys, loadState, storeState, workerIterationEnd, workerIterationStart

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."

Specified by:

setup in interface VertexProgram<org.javatuples.Tuple>

Parameters:

memory - The global memory of the GraphComputer

execute

public void execute(Vertex sourceVertex,
                    Messenger<org.javatuples.Tuple> 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.

Specified by:

execute in interface VertexProgram<org.javatuples.Tuple>

Parameters:

sourceVertex - 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.

Specified by:

terminate in interface VertexProgram<org.javatuples.Tuple>

Parameters:

memory - The global memory of the GraphComputer

Returns:

whether or not to halt the computation

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.

Specified by:

getMessageScopes in interface VertexProgram<org.javatuples.Tuple>

Parameters:

memory - an immutable form of the Memory

Returns:

all possible message scopes during said vertex program iteration

clone

public VertexProgram<org.javatuples.Tuple> clone()

Description copied from interface: VertexProgram

When multiple workers on a single machine need VertexProgram instances, it is possible to use clone. This will provide a speedier way of generating instances, over the VertexProgram.storeState(org.apache.commons.configuration2.Configuration) and VertexProgram.loadState(org.apache.tinkerpop.gremlin.structure.Graph, org.apache.commons.configuration2.Configuration) model. The default implementation simply returns the object as it assumes that the VertexProgram instance is a stateless singleton.

Specified by:

clone in interface VertexProgram<org.javatuples.Tuple>

Overrides:

clone in class Object

Returns:

A clone of the VertexProgram object

getPreferredResultGraph

public GraphComputer.ResultGraph getPreferredResultGraph()

Specified by:

getPreferredResultGraph in interface VertexProgram<org.javatuples.Tuple>

getPreferredPersist

public GraphComputer.Persist getPreferredPersist()

Specified by:

getPreferredPersist in interface VertexProgram<org.javatuples.Tuple>

toString

public String toString()

Overrides:

toString in class Object

build

public static CloneVertexProgram.Builder build()