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

Interface Traversal.Admin<S,E>

All Superinterfaces:

AutoCloseable, Cloneable, Iterator<E>, Serializable, Traversal<S,E>

All Known Subinterfaces:

GraphTraversal.Admin<S,E>

Enclosing interface:

Traversal<S,E>

public static interface Traversal.Admin<S,E>
extends Traversal<S,E>

Nested Class Summary

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

Traversal.Admin<S,E>, Traversal.Exceptions, Traversal.Symbols

Method Summary

Modifier and Type	Method	Description
default void	addStart(Traverser.Admin<S> start)	Add a single Traverser.Admin object to the head of the traversal.
default void	addStarts(Iterator<Traverser.Admin<S>> starts)	Add an iterator of Traverser.Admin objects to the head/start of the traversal.
<S2,E2> Traversal.Admin<S2,E2>	addStep(int index, Step<?,?> step)	Add a Step to an arbitrary point in the traversal.
default <E2> Traversal.Admin<S,E2>	addStep(Step<?,E2> step)	Add a Step to the end of the traversal.
void	applyStrategies()	Apply the registered TraversalStrategies to the traversal.
Traversal.Admin<S,E>	clone()	Cloning is used to duplicate the traversal typically in OLAP environments.
default boolean	equals(Traversal.Admin<S,E> other)
Bytecode	getBytecode()	Get the Bytecode associated with the construction of this traversal.
default Step<?,E>	getEndStep()	Get the end/tail of the traversal.
Optional<Graph>	getGraph()	Gets the Graph instance associated directly to this Traversal or through its parent.
org.apache.tinkerpop.gremlin.process.traversal.step.TraversalParent	getParent()	Get the TraversalParent Step that is the parent of this traversal.
TraversalSideEffects	getSideEffects()	Get the TraversalSideEffects associated with the traversal.
default Step<S,?>	getStartStep()	Get the start/head of the traversal.
List<Step>	getSteps()	Get the Step instances associated with this traversal.
TraversalStrategies	getStrategies()	Get the TraversalStrategies associated with this traversal.
default Optional<TraversalSource>	getTraversalSource()	Gets the TraversalSource that spawned the Traversal instance initially if present.
TraverserGenerator	getTraverserGenerator()	Get the TraverserGenerator associated with this traversal.
Set<org.apache.tinkerpop.gremlin.process.traversal.traverser.TraverserRequirement>	getTraverserRequirements()	Get the set of all TraverserRequirements for this traversal.
default Supplier<org.apache.tinkerpop.gremlin.process.traversal.traverser.util.TraverserSet<S>>	getTraverserSetSupplier()	Gets a generator that creates new TraverserSet instances for steps in the traversal.
boolean	isLocked()	When the traversal has had its TraversalStrategies applied to it, it is locked.
default boolean	isRoot()	Determines if the traversal is at the root level.
void	lock()	Lock the traversal and perform any final adjustments to it after strategy application.
default Traverser.Admin<E>	nextTraverser()
<S2,E2> Traversal.Admin<S2,E2>	removeStep(int index)	Remove a Step from the traversal.
default <S2,E2> Traversal.Admin<S2,E2>	removeStep(Step<?,?> step)	Remove a Step from the traversal.
default void	reset()	Call the Step.reset() method on every step in the traversal.
void	setGraph(Graph graph)
void	setParent(org.apache.tinkerpop.gremlin.process.traversal.step.TraversalParent step)	Set the TraversalParent Step that is the parent of this traversal.
void	setSideEffects(TraversalSideEffects sideEffects)	Set the TraversalSideEffects of this traversal.
void	setStrategies(TraversalStrategies strategies)	Set the TraversalStrategies to be used by this traversal at evaluation time.

Methods inherited from interface java.util.Iterator

hasNext, next, remove

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

asAdmin, close, explain, fill, forEachRemaining, forEachRemaining, iterate, next, none, notifyClose, profile, promise, toBulkSet, toList, toSet, toStream, tryNext

Method Detail

getBytecode

Bytecode getBytecode()

Get the Bytecode associated with the construction of this traversal.

Returns:

the byte code representation of the traversal

addStarts

default void addStarts(Iterator<Traverser.Admin<S>> starts)

Add an iterator of Traverser.Admin objects to the head/start of the traversal. Users should typically not need to call this method. For dynamic inject of data, they should use InjectStep.

Parameters:

starts - an iterators of traversers

addStart

default void addStart(Traverser.Admin<S> start)

Add a single Traverser.Admin object to the head of the traversal. Users should typically not need to call this method. For dynamic inject of data, they should use InjectStep.

Parameters:

start - a traverser to add to the traversal

getSteps

List<Step> getSteps()

Get the Step instances associated with this traversal. The steps are ordered according to their linked list structure as defined by Step.getPreviousStep() and Step.getNextStep().

Returns:

the ordered steps of the traversal

addStep

default <E2> Traversal.Admin<S,E2> addStep(Step<?,E2> step)
                                          throws IllegalStateException

Add a Step to the end of the traversal. This method should link the step to its next and previous step accordingly.

Type Parameters:

E2 - the output of the step

Parameters:

step - the step to add

Returns:

the updated traversal

Throws:

IllegalStateException - if the TraversalStrategies have already been applied

addStep

<S2,E2> Traversal.Admin<S2,E2> addStep(int index,
                                                   Step<?,?> step)
                                            throws IllegalStateException

Add a Step to an arbitrary point in the traversal.

Type Parameters:

S2 - the new start type of the traversal (if the added step was a start step)

E2 - the new end type of the traversal (if the added step was an end step)

Parameters:

index - the location in the traversal to insert the step

step - the step to add

Returns:

the newly modulated traversal

Throws:

IllegalStateException - if the TraversalStrategies have already been applied

removeStep

default <S2,E2> Traversal.Admin<S2,E2> removeStep(Step<?,?> step)
                                                       throws IllegalStateException

Remove a Step from the traversal.

Type Parameters:

S2 - the new start type of the traversal (if the removed step was a start step)

E2 - the new end type of the traversal (if the removed step was an end step)

Parameters:

step - the step to remove

Returns:

the newly modulated traversal

Throws:

IllegalStateException - if the TraversalStrategies have already been applied

removeStep

<S2,E2> Traversal.Admin<S2,E2> removeStep(int index)
                                               throws IllegalStateException

Remove a Step from the traversal.

Type Parameters:

S2 - the new start type of the traversal (if the removed step was a start step)

E2 - the new end type of the traversal (if the removed step was an end step)

Parameters:

index - the location in the traversal of the step to be evicted

Returns:

the newly modulated traversal

Throws:

IllegalStateException - if the TraversalStrategies have already been applied

getStartStep

default Step<S,?> getStartStep()

Get the start/head of the traversal. If the traversal is empty, then an EmptyStep instance is returned.

Returns:

the start step of the traversal

getEndStep

default Step<?,E> getEndStep()

Get the end/tail of the traversal. If the traversal is empty, then an EmptyStep instance is returned.

Returns:

the end step of the traversal

applyStrategies

void applyStrategies()
              throws IllegalStateException

Apply the registered TraversalStrategies to the traversal. Once the strategies are applied, the traversal is "locked" and can no longer have steps added to it. The order of operations for strategy applications should be: globally id steps, apply each strategy in turn to root traversal, then recursively to nested traversals.

Throws:

IllegalStateException - if the TraversalStrategies have already been applied

getTraverserGenerator

TraverserGenerator getTraverserGenerator()

Get the TraverserGenerator associated with this traversal. The traversal generator creates Traverser instances that are respective of the traversal's TraverserRequirement.

Returns:

the generator of traversers

getTraverserSetSupplier

default Supplier<org.apache.tinkerpop.gremlin.process.traversal.traverser.util.TraverserSet<S>> getTraverserSetSupplier()

Gets a generator that creates new TraverserSet instances for steps in the traversal. Providers may override this default implementation to provider their own TraverserSet.

getTraverserRequirements

Set<org.apache.tinkerpop.gremlin.process.traversal.traverser.TraverserRequirement> getTraverserRequirements()

Get the set of all TraverserRequirements for this traversal.

Returns:

the features of a traverser that are required to execute properly in this traversal

reset

default void reset()

Call the Step.reset() method on every step in the traversal.

setSideEffects

void setSideEffects(TraversalSideEffects sideEffects)

Set the TraversalSideEffects of this traversal.

Parameters:

sideEffects - the sideEffects to set for this traversal.

getSideEffects

TraversalSideEffects getSideEffects()

Get the TraversalSideEffects associated with the traversal. This method should not be called externally for purposes of retrieving side-effects as traversal results. Traversal results should only be returned by way of the execution of the traversal itself. Should a side-effect of a traversal be needed it should only be obtained by using GraphTraversal.cap(String, String...) so that the side-effect can be included as part of the traversal iteration. Relying on this method to get side-effects in these situations may not result in consistent behavior across all types of executions and environments (e.g. remoting).

Returns:

The traversal sideEffects

setStrategies

void setStrategies(TraversalStrategies strategies)

Set the TraversalStrategies to be used by this traversal at evaluation time.

Parameters:

strategies - the strategies to use on this traversal

getStrategies

TraversalStrategies getStrategies()

Get the TraversalStrategies associated with this traversal.

Returns:

the strategies associated with this traversal

setParent

void setParent(org.apache.tinkerpop.gremlin.process.traversal.step.TraversalParent step)

Set the TraversalParent Step that is the parent of this traversal. Traversals can be nested and this is the means by which the traversal tree is connected. If there is no parent, then it should be a EmptyStep.

Parameters:

step - the traversal holder parent step or EmptyStep if it has no parent

getParent

org.apache.tinkerpop.gremlin.process.traversal.step.TraversalParent getParent()

Get the TraversalParent Step that is the parent of this traversal. Traversals can be nested and this is the means by which the traversal tree is walked.

Returns:

the traversal holder parent step or EmptyStep if it has no parent.

isRoot

default boolean isRoot()

Determines if the traversal is at the root level.

clone

Traversal.Admin<S,E> clone()

Cloning is used to duplicate the traversal typically in OLAP environments.

Returns:

The cloned traversal

isLocked

boolean isLocked()

When the traversal has had its TraversalStrategies applied to it, it is locked.

Returns:

whether the traversal is locked

lock

void lock()

Lock the traversal and perform any final adjustments to it after strategy application.

getGraph

Optional<Graph> getGraph()

Gets the Graph instance associated directly to this Traversal or through its parent.

getTraversalSource

default Optional<TraversalSource> getTraversalSource()

Gets the TraversalSource that spawned the Traversal instance initially if present. This TraversalSource should have spawned from the associated Graph returned from getGraph().

setGraph

void setGraph(Graph graph)

equals

default boolean equals(Traversal.Admin<S,E> other)

nextTraverser

default Traverser.Admin<E> nextTraverser()