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

Class DedupGlobalStep<S>

java.lang.Object

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

org.apache.tinkerpop.gremlin.process.traversal.step.filter.FilterStep<S>

org.apache.tinkerpop.gremlin.process.traversal.step.filter.DedupGlobalStep<S>

All Implemented Interfaces:

Serializable, AutoCloseable, Cloneable, Iterator<Traverser.Admin<S>>, Step<S,S>, Barrier<Map<Object,Traverser.Admin<S>>>, ByModulating, GraphComputing, MemoryComputing<Map<Object,Traverser.Admin<S>>>, PathProcessor, Scoping, TraversalParent

public final class DedupGlobalStep<S>
extends FilterStep<S>
implements TraversalParent, Scoping, GraphComputing, Barrier<Map<Object,Traverser.Admin<S>>>, ByModulating, PathProcessor

Author:

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

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.Scoping

Scoping.Variable

Nested classes/interfaces inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.PathProcessor

PathProcessor.ElementRequirement

Field Summary

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

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

Fields inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.Scoping

TYPICAL_GLOBAL_REQUIREMENTS, TYPICAL_GLOBAL_REQUIREMENTS_ARRAY, TYPICAL_LOCAL_REQUIREMENTS, TYPICAL_LOCAL_REQUIREMENTS_ARRAY

Constructor Summary

Constructors

Constructor and Description
DedupGlobalStep(Traversal.Admin traversal, String... dedupLabels)

Method Summary

Modifier and Type	Method and Description
void	addBarrier(Map<Object,Traverser.Admin<S>> barrier) Add a barrier to the step.
void	atMaster(boolean atMaster) Some steps should behave different whether they are executing at the master traversal or distributed across the worker traversals.
DedupGlobalStep<S>	clone() Cloning is used to duplicate steps for the purpose of traversal optimization and OLTP replication.
protected boolean	filter(Traverser.Admin<S> traverser)
Set<String>	getKeepLabels()
List<Traversal<S,Object>>	getLocalChildren()
PathProcessor.ElementRequirement	getMaxRequirement()
MemoryComputeKey<Map<Object,Traverser.Admin<S>>>	getMemoryComputeKey() The MemoryComputeKey that will be used by this step.
Set<TraverserRequirement>	getRequirements() Provide the necessary TraverserRequirement that must be met by the traverser in order for the step to function properly.
Set<String>	getScopeKeys()
int	hashCode()
boolean	hasNextBarrier() Whether or not the step has an accessible barrier.
void	modulateBy(Traversal.Admin<?,?> dedupTraversal)
Map<Object,Traverser.Admin<S>>	nextBarrier() Get the next barrier within this step.
void	onGraphComputer() The step will be executing on a GraphComputer.
void	processAllStarts() Process all left traversers by do not yield the resultant output.
protected Traverser.Admin<S>	processNextStart()
void	reset() Reset the state of the step such that it has no incoming starts.
void	setKeepLabels(Set<String> labels)
void	setTraversal(Traversal.Admin<?,?> parentTraversal) Set the Traversal that this step is contained within.
String	toString()

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

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

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.TraversalParent

addGlobalChild, addLocalChild, asStep, close, getGlobalChildren, getSelfAndChildRequirements, integrateChild, removeGlobalChild, removeLocalChild

Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.Scoping

getNullableScopeValue, getScopeValue

Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.GraphComputing

atMaster

Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.Barrier

done

Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.ByModulating

modulateBy, modulateBy, modulateBy, modulateBy, modulateBy, modulateBy, modulateBy, modulateBy, modulateBy, modulateBy, modulateBy

Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.PathProcessor

processTraverserPathLabels

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

equals

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Constructor Detail

DedupGlobalStep

public DedupGlobalStep(Traversal.Admin traversal,
                       String... dedupLabels)

Method Detail

filter

protected boolean filter(Traverser.Admin<S> traverser)

Specified by:

filter in class FilterStep<S>

atMaster

public void atMaster(boolean atMaster)

Description copied from interface: GraphComputing

Some steps should behave different whether they are executing at the master traversal or distributed across the worker traversals. The default implementation does nothing.

Specified by:

atMaster in interface GraphComputing

Parameters:

atMaster - whether the step is currently executing at master

getMaxRequirement

public PathProcessor.ElementRequirement getMaxRequirement()

Specified by:

getMaxRequirement in interface PathProcessor

processNextStart

protected Traverser.Admin<S> processNextStart()

Overrides:

processNextStart in class FilterStep<S>

getLocalChildren

public List<Traversal<S,Object>> getLocalChildren()

Specified by:

getLocalChildren in interface TraversalParent

modulateBy

public void modulateBy(Traversal.Admin<?,?> dedupTraversal)

Specified by:

modulateBy in interface ByModulating

clone

public DedupGlobalStep<S> 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,S>

Overrides:

clone in class AbstractStep<S,S>

Returns:

The cloned step

setTraversal

public void setTraversal(Traversal.Admin<?,?> parentTraversal)

Description copied from interface: Step

Set the Traversal that this step is contained within.

Specified by:

setTraversal in interface Step<S,S>

Overrides:

setTraversal in class AbstractStep<S,S>

Parameters:

parentTraversal - the new traversal for this step

hashCode

public int hashCode()

Overrides:

hashCode in class AbstractStep<S,S>

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,S>

Overrides:

reset in class AbstractStep<S,S>

toString

public String toString()

Overrides:

toString in class AbstractStep<S,S>

getRequirements

public Set<TraverserRequirement> getRequirements()

Description copied from interface: Step

Provide the necessary TraverserRequirement that must be met by the traverser in order for the step to function properly. The provided default implements returns an empty set.

Specified by:

getRequirements in interface Step<S,S>

Returns:

the set of requirements

onGraphComputer

public void onGraphComputer()

Description copied from interface: GraphComputing

The step will be executing on a GraphComputer.

Specified by:

onGraphComputer in interface GraphComputing

getScopeKeys

public Set<String> getScopeKeys()

Specified by:

getScopeKeys in interface Scoping

processAllStarts

public void processAllStarts()

Description copied from interface: Barrier

Process all left traversers by do not yield the resultant output. This method is useful for steps like ReducingBarrierStep, where traversers can be processed "on the fly" and thus, reduce memory consumption.

Specified by:

processAllStarts in interface Barrier<Map<Object,Traverser.Admin<S>>>

hasNextBarrier

public boolean hasNextBarrier()

Description copied from interface: Barrier

Whether or not the step has an accessible barrier.

Specified by:

hasNextBarrier in interface Barrier<Map<Object,Traverser.Admin<S>>>

Returns:

whether a barrier exists or not

nextBarrier

public Map<Object,Traverser.Admin<S>> nextBarrier()
                                           throws NoSuchElementException

Description copied from interface: Barrier

Get the next barrier within this step. Barriers from parallel steps can be the be merged to create a single step with merge barriers.

Specified by:

nextBarrier in interface Barrier<Map<Object,Traverser.Admin<S>>>

Returns:

the next barrier of the step

Throws:

NoSuchElementException

addBarrier

public void addBarrier(Map<Object,Traverser.Admin<S>> barrier)

Description copied from interface: Barrier

Add a barrier to the step. This typically happens when multiple parallel barriers need to become one barrier at a single step.

Specified by:

addBarrier in interface Barrier<Map<Object,Traverser.Admin<S>>>

Parameters:

barrier - the barrier to merge in

getMemoryComputeKey

public MemoryComputeKey<Map<Object,Traverser.Admin<S>>> getMemoryComputeKey()

Description copied from interface: MemoryComputing

The MemoryComputeKey that will be used by this step.

Specified by:

getMemoryComputeKey in interface MemoryComputing<Map<Object,Traverser.Admin<S>>>

Returns:

the MemoryComputeKey to use

setKeepLabels

public void setKeepLabels(Set<String> labels)

Specified by:

setKeepLabels in interface PathProcessor

getKeepLabels

public Set<String> getKeepLabels()

Specified by:

getKeepLabels in interface PathProcessor