org.apache.tinkerpop.gremlin.process.traversal.step.util

Class ReducingBarrierStep<S,E>

java.lang.Object

org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep<S,E>

org.apache.tinkerpop.gremlin.process.traversal.step.util.ReducingBarrierStep<S,E>

All Implemented Interfaces:

Serializable, Cloneable, Iterator<Traverser<E>>, Step<S,E>, EngineDependent, MapReducer

Direct Known Subclasses:

CountGlobalStep, FoldStep, GroupCountStep, GroupStep, MaxGlobalStep, MeanGlobalStep, MinGlobalStep, SumGlobalStep, TreeStep

public abstract class ReducingBarrierStep<S,E>
extends AbstractStep<S,E>
implements MapReducer, EngineDependent

Author:

Marko A. Rodriguez (http://markorodriguez.com)

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ReducingBarrierStep.DefaultMapReduce
static interface	ReducingBarrierStep.FinalGet<A>

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	byPass
static String	REDUCING
protected BiFunction<E,Traverser<S>,E>	reducingBiFunction
protected Supplier<E>	seedSupplier

Fields inherited from class org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep

id, labels, nextEnd, nextStep, previousStep, starts, traversal, traverserStepIdSetByChild

Constructor Summary

Constructors

Constructor and Description
ReducingBarrierStep(Traversal.Admin traversal)

Method Summary

Modifier and Type	Method and Description
ReducingBarrierStep<S,E>	clone() Cloning is used to duplicate steps for the purpose of traversal optimization and OLTP replication.
MapReduce	getMapReduce()
void	onEngine(TraversalEngine traversalEngine)
Traverser<E>	processNextStart()
void	reset() Reset the state of the step such that it has no incoming starts.
void	setBiFunction(BiFunction<E,Traverser<S>,E> reducingBiFunction)
void	setSeedSupplier(Supplier<E> seedSupplier)

Methods inherited from class org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep

addLabel, addStart, addStarts, equals, getId, getLabels, getNextStep, getPreviousStep, getTraversal, hashCode, hasNext, next, removeLabel, setId, setNextStep, setPreviousStep, setTraversal, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.Step

equals, getRequirements

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Field Detail

REDUCING

public static final String REDUCING

seedSupplier

protected Supplier<E> seedSupplier

reducingBiFunction

protected BiFunction<E,Traverser<S>,E> reducingBiFunction

byPass

protected boolean byPass

Constructor Detail

ReducingBarrierStep

public ReducingBarrierStep(Traversal.Admin traversal)

Method Detail

setSeedSupplier

public void setSeedSupplier(Supplier<E> seedSupplier)

setBiFunction

public void setBiFunction(BiFunction<E,Traverser<S>,E> reducingBiFunction)

onEngine

public void onEngine(TraversalEngine traversalEngine)

Specified by:

onEngine in interface EngineDependent

reset

public void reset()

Description copied from interface: Step

Reset the state of the step such that it has no incoming starts. Internal states are to be reset, but any sideEffect data structures are not to be recreated.

Specified by:

reset in interface Step<S,E>

Overrides:

reset in class AbstractStep<S,E>

processNextStart

public Traverser<E> processNextStart()

Specified by:

processNextStart in class AbstractStep<S,E>

clone

public ReducingBarrierStep<S,E> clone()

Description copied from interface: Step

Cloning is used to duplicate steps for the purpose of traversal optimization and OLTP replication. When cloning a step, it is important that the steps, the cloned step is equivalent to the state of the step when reset() is called. Moreover, the previous and next steps should be set to EmptyStep.

Specified by:

clone in interface Step<S,E>

Overrides:

clone in class AbstractStep<S,E>

Returns:

The cloned step

getMapReduce

public MapReduce getMapReduce()

Specified by:

getMapReduce in interface MapReducer