org.apache.tinkerpop.gremlin.process.computer

Class GraphComputerTest.MapReduceC

java.lang.Object

org.apache.tinkerpop.gremlin.process.computer.util.StaticMapReduce<MapReduce.NullObject,MapReduce.NullObject,MapReduce.NullObject,MapReduce.NullObject,MapReduce.NullObject>

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

All Implemented Interfaces:

Cloneable, MapReduce<MapReduce.NullObject,MapReduce.NullObject,MapReduce.NullObject,MapReduce.NullObject,MapReduce.NullObject>

Enclosing class:

GraphComputerTest

public static class GraphComputerTest.MapReduceC
extends StaticMapReduce<MapReduce.NullObject,MapReduce.NullObject,MapReduce.NullObject,MapReduce.NullObject,MapReduce.NullObject>

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
MapReduceC()

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.
MapReduce.NullObject	generateFinalResult(Iterator<KeyValue<MapReduce.NullObject,MapReduce.NullObject>> 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<MapReduce.NullObject,MapReduce.NullObject> 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

MapReduceC

public MapReduceC()

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<MapReduce.NullObject,MapReduce.NullObject> 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 MapReduce.NullObject generateFinalResult(Iterator<KeyValue<MapReduce.NullObject,MapReduce.NullObject>> 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.