org.apache.tinkerpop.gremlin.process.computer

Class GraphComputerTest.MapReduceK

java.lang.Object

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

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

All Implemented Interfaces:

Cloneable, MapReduce

Enclosing class:

GraphComputerTest

public static class GraphComputerTest.MapReduceK
extends StaticMapReduce

Nested Class Summary

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

MapReduce.MapEmitter<K,V>, MapReduce.NullObject, MapReduce.ReduceEmitter<OK,OV>, MapReduce.Stage

Field Summary

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

MAP_REDUCE

Constructor Summary

Constructors

Constructor and Description
MapReduceK()

Method Summary

Modifier and Type	Method and Description
boolean	doStage(MapReduce.Stage stage) A MapReduce job can be map-only, map-reduce-only, or map-combine-reduce.
Object	generateFinalResult(Iterator keyValues) The key/value pairs emitted by reduce() (or map() in a map-only job) can be iterated to generate a local JVM Java object.
String	getMemoryKey() The results of the MapReduce job are associated with a memory-key to ultimately be stored in Memory.
void	map(Vertex vertex, MapReduce.MapEmitter emitter) The map() method is logically executed at all vertices in the graph in parallel.

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

clone, equals, hashCode, storeState, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

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

addResultToMemory, combine, createMapReduce, getMapKeySort, getReduceKeySort, loadState, reduce, workerEnd, workerStart

Constructor Detail

MapReduceK

public MapReduceK()

Method Detail

doStage

public boolean doStage(MapReduce.Stage stage)

Description copied from interface: MapReduce

A MapReduce job can be map-only, map-reduce-only, or map-combine-reduce. Before executing the particular stage, this method is called to determine if the respective stage is defined. This method should return true if the respective stage as a non-default method implementation.

Parameters:

stage - the stage to check for definition.

Returns:

whether that stage should be executed.

map

public void map(Vertex vertex,
                MapReduce.MapEmitter emitter)

Description copied from interface: MapReduce

The map() method is logically executed at all vertices in the graph in parallel. The map() method emits key/value pairs given some analysis of the data in the vertices (and/or its incident edges). All MapReduce classes must at least provide an implementation of MapReduce#map(Vertex, MapEmitter).

Parameters:

vertex - the current vertex being map() processed.

emitter - the component that allows for key/value pairs to be emitted to the next stage.

getMemoryKey

public String getMemoryKey()

Description copied from interface: MapReduce

The results of the MapReduce job are associated with a memory-key to ultimately be stored in Memory.

Returns:

the memory key of the generated result object.

generateFinalResult

public Object generateFinalResult(Iterator keyValues)

Description copied from interface: MapReduce

The key/value pairs emitted by reduce() (or map() in a map-only job) can be iterated to generate a local JVM Java object.

Parameters:

keyValues - the key/value pairs that were emitted from reduce() (or map() in a map-only job)

Returns:

the resultant object formed from the emitted key/values.