Package org.apache.tinkerpop.gremlin.process.traversal.step.branch

Class BranchStep<S,E,M>

java.lang.Object

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

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

org.apache.tinkerpop.gremlin.process.traversal.step.branch.BranchStep<S,E,M>

All Implemented Interfaces:

Serializable, AutoCloseable, Cloneable, Iterator<Traverser.Admin<E>>, Step<S,E>, GraphComputing, PopContaining, TraversalOptionParent<M,S,E>, TraversalParent

Direct Known Subclasses:

ChooseStep, UnionStep

public class BranchStep<S,E,M>
extends ComputerAwareStep<S,E>
implements TraversalOptionParent<M,S,E>

Author:

Marko A. Rodriguez (http://markorodriguez.com), Daniel Kuppitz (http://gremlin.guru)

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.tinkerpop.gremlin.process.traversal.step.util.ComputerAwareStep

ComputerAwareStep.EndStep<S>

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

PopContaining.PopInstruction

Field Summary

Fields

Modifier and Type	Field	Description
protected Traversal.Admin<S,M>	branchTraversal
protected boolean	hasBarrier
protected List<org.javatuples.Pair<Traversal.Admin<M,?>,Traversal.Admin<S,E>>>	traversalOptions
protected Map<Pick,List<Traversal.Admin<S,E>>>	traversalPickOptions

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

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

Constructor Summary

Constructors

Constructor	Description
BranchStep(Traversal.Admin traversal)

Method Summary

Modifier and Type	Method	Description
void	addChildOption(M pickToken, Traversal.Admin<S,E> traversalOption)	The child as defined by the token it takes, like Pick or Merge.
protected void	applyCurrentTraverser(Traverser.Admin<S> start)	Choose the right traversal option to apply and seed those options with this traverser.
BranchStep<S,E,M>	clone()	Cloning is used to duplicate steps for the purpose of traversal optimization and OLTP replication.
protected Iterator<Traverser.Admin<E>>	computerAlgorithm()
Traversal.Admin<S,M>	getBranchTraversal()
List<Traversal.Admin<S,E>>	getGlobalChildren()	Gets a list of all "global" child traversals for this step.
List<Traversal.Admin<?,?>>	getLocalChildren()	Gets a list of all "local" child traversals for this step.
Set<TraverserRequirement>	getRequirements()	Provide the necessary TraverserRequirement that must be met by the traverser in order for the step to function properly.
List<org.javatuples.Pair<Traversal.Admin<M,?>,Traversal.Admin<S,E>>>	getTraversalOptions()
Map<Pick,List<Traversal.Admin<S,E>>>	getTraversalPickOptions()
int	hashCode()
protected List<Traversal.Admin<S,E>>	pickBranches(M choice)
void	reset()	Reset the state of the step such that it has no incoming starts.
void	setBranchTraversal(Traversal.Admin<S,M> branchTraversal)
void	setTraversal(Traversal.Admin<?,?> parentTraversal)	Set the Traversal that this step is contained within.
protected Iterator<Traverser.Admin<E>>	standardAlgorithm()
String	toString()

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

onGraphComputer, processNextStart

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

addLabel, addStart, addStarts, clearLabels, equals, getId, getLabels, getNextStep, getPreviousStep, getStarts, getTraversal, hasNext, hasStarts, isTraverserStepIdAndLabelsSetByChild, next, prepareTraversalForNextStep, 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.GraphComputing

atMaster

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

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

equals

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

addGlobalChild, addLocalChild, asStep, close, getPopInstructions, getSelfAndChildRequirements, integrateChild, removeGlobalChild, removeLocalChild, replaceLocalChild

Field Details

branchTraversal

protected Traversal.Admin<S,M> branchTraversal

traversalPickOptions

protected Map<Pick,List<Traversal.Admin<S,E>>> traversalPickOptions

traversalOptions

protected List<org.javatuples.Pair<Traversal.Admin<M,?>,Traversal.Admin<S,E>>> traversalOptions

hasBarrier

protected boolean hasBarrier

Constructor Details

BranchStep

public BranchStep(Traversal.Admin traversal)

Method Details

setBranchTraversal

public void setBranchTraversal(Traversal.Admin<S,M> branchTraversal)

addChildOption

public void addChildOption(M pickToken,
 Traversal.Admin<S,E> traversalOption)

Description copied from interface: TraversalOptionParent

The child as defined by the token it takes, like Pick or Merge. This traversal may be of local or global scope depending on the step implementation that works with option().

Specified by:

addChildOption in interface TraversalOptionParent<S,E,M>

getTraversalOptions

public List<org.javatuples.Pair<Traversal.Admin<M,?>,Traversal.Admin<S,E>>> getTraversalOptions()

getTraversalPickOptions

public Map<Pick,List<Traversal.Admin<S,E>>> getTraversalPickOptions()

getBranchTraversal

public Traversal.Admin<S,M> getBranchTraversal()

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,E>

Returns:

the set of requirements

getGlobalChildren

public List<Traversal.Admin<S,E>> getGlobalChildren()

Description copied from interface: TraversalParent

Gets a list of all "global" child traversals for this step. A "global" traversal is one which evaluates across all of its parents incoming traversers at once. This is typically used in cases where the child traversal represents a branch of traversal flow. See BranchStep as an example.

Specified by:

getGlobalChildren in interface TraversalParent

getLocalChildren

public List<Traversal.Admin<?,?>> getLocalChildren()

Description copied from interface: TraversalParent

Gets a list of all "local" child traversals for this step. A "local" traversal is one which is evaluated independently for each incoming traverser to the parent step. This is typically used in cases where the child is used to process or augment each traverser individually. See LocalStep or ByModulating as examples.

Specified by:

getLocalChildren in interface TraversalParent

standardAlgorithm

protected Iterator<Traverser.Admin<E>> standardAlgorithm()

Specified by:

standardAlgorithm in class ComputerAwareStep<S,E>

applyCurrentTraverser

protected void applyCurrentTraverser(Traverser.Admin<S> start)

Choose the right traversal option to apply and seed those options with this traverser.

computerAlgorithm

protected Iterator<Traverser.Admin<E>> computerAlgorithm()

Specified by:

computerAlgorithm in class ComputerAwareStep<S,E>

pickBranches

protected List<Traversal.Admin<S,E>> pickBranches(M choice)

clone

public BranchStep<S,E,M> 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 Step.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 ComputerAwareStep<S,E>

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,E>

Overrides:

setTraversal in class AbstractStep<S,E>

Parameters:

parentTraversal - the new traversal for this step

hashCode

public int hashCode()

Overrides:

hashCode in class AbstractStep<S,E>

toString

public String toString()

Overrides:

toString in class AbstractStep<S,E>

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 ComputerAwareStep<S,E>