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

Class DefaultTraversal<S,E>

java.lang.Object

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

All Implemented Interfaces:

Serializable, Cloneable, Iterator<E>, Traversal<S,E>, Traversal.Admin<S,E>

Direct Known Subclasses:

DefaultGraphTraversal

public class DefaultTraversal<S,E>
extends Object
implements Traversal.Admin<S,E>

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.Traversal

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

Field Summary

Fields

Modifier and Type	Field and Description
protected Graph	graph
protected boolean	locked
protected TraversalSideEffects	sideEffects
protected List<Step>	steps
protected TraversalStrategies	strategies
protected TraversalEngine	traversalEngine
protected TraversalParent	traversalParent

Constructor Summary

Constructors

Constructor and Description
DefaultTraversal()
DefaultTraversal(Graph graph)

Method Summary

Modifier and Type	Method and Description
void	addStart(Traverser<S> start) Add a single Traverser object to the head of the traversal.
void	addStarts(Iterator<Traverser<S>> starts) Add an iterator of Traverser 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.
void	applyStrategies() Apply the registered TraversalStrategies to the traversal.
Traversal.Admin<S,E>	asAdmin() Get access to administrative methods of the traversal via its accompanying Traversal.Admin.
DefaultTraversal<S,E>	clone() Cloning is used to duplicate the traversal typically in OLAP environments.
Step<?,E>	getEndStep() Get the end/tail of the traversal.
TraversalEngine	getEngine() Get the TraversalEngine that will be used to execute this traversal.
Optional<Graph>	getGraph()
TraversalParent	getParent() Get the TraversalParent Step that is the parent of this traversal.
TraversalSideEffects	getSideEffects() Get the TraversalSideEffects associated with the traversal.
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.
boolean	hasNext()
boolean	isLocked() When the traversal has had its TraversalStrategies applied to it, it is locked.
E	next()
<S2,E2> Traversal.Admin<S2,E2>	removeStep(int index) Remove a Step from the traversal.
void	reset() Call the Step.reset() method on every step in the traversal.
void	setEngine(TraversalEngine engine) Set the TraversalEngine to be used for executing this traversal.
void	setGraph(Graph graph)
void	setParent(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.
String	toString()

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

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

addStep, equals, getTraverserGenerator, getTraverserRequirements, removeStep

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

fill, forEachRemaining, forEachRemaining, iterate, next, toBulkSet, toList, toSet, toStream, tryNext

Methods inherited from interface java.util.Iterator

remove

Field Detail

graph

protected transient Graph graph

steps

protected List<Step> steps

traversalParent

protected TraversalParent traversalParent

sideEffects

protected TraversalSideEffects sideEffects

strategies

protected TraversalStrategies strategies

traversalEngine

protected TraversalEngine traversalEngine

locked

protected boolean locked

Constructor Detail

DefaultTraversal

public DefaultTraversal()

DefaultTraversal

public DefaultTraversal(Graph graph)

Method Detail

asAdmin

public Traversal.Admin<S,E> asAdmin()

Description copied from interface: Traversal

Get access to administrative methods of the traversal via its accompanying Traversal.Admin.

Specified by:

asAdmin in interface Traversal<S,E>

Returns:

the admin of this traversal

applyStrategies

public void applyStrategies()
                     throws IllegalStateException

Description copied from interface: Traversal.Admin

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 strategies to root traversal, then to nested traversals.

Specified by:

applyStrategies in interface Traversal.Admin<S,E>

Throws:

IllegalStateException - if the TraversalStrategies have already been applied

getEngine

public TraversalEngine getEngine()

Description copied from interface: Traversal.Admin

Get the TraversalEngine that will be used to execute this traversal.

Specified by:

getEngine in interface Traversal.Admin<S,E>

Returns:

get the traversal engine associated with this traversal.

setEngine

public void setEngine(TraversalEngine engine)

Description copied from interface: Traversal.Admin

Set the TraversalEngine to be used for executing this traversal.

Specified by:

setEngine in interface Traversal.Admin<S,E>

Parameters:

engine - the engine to execute the traversal with.

getSteps

public List<Step> getSteps()

Description copied from interface: Traversal.Admin

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().

Specified by:

getSteps in interface Traversal.Admin<S,E>

Returns:

the ordered steps of the traversal

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<E>

next

public E next()

Specified by:

next in interface Iterator<E>

reset

public void reset()

Description copied from interface: Traversal.Admin

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

Specified by:

reset in interface Traversal.Admin<S,E>

addStart

public void addStart(Traverser<S> start)

Description copied from interface: Traversal.Admin

Add a single Traverser 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.

Specified by:

addStart in interface Traversal.Admin<S,E>

Parameters:

start - a traverser to add to the traversal

addStarts

public void addStarts(Iterator<Traverser<S>> starts)

Description copied from interface: Traversal.Admin

Add an iterator of Traverser 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.

Specified by:

addStarts in interface Traversal.Admin<S,E>

Parameters:

starts - an iterators of traversers

toString

public String toString()

Overrides:

toString in class Object

getStartStep

public Step<S,?> getStartStep()

Description copied from interface: Traversal.Admin

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

Specified by:

getStartStep in interface Traversal.Admin<S,E>

Returns:

the start step of the traversal

getEndStep

public Step<?,E> getEndStep()

Description copied from interface: Traversal.Admin

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

Specified by:

getEndStep in interface Traversal.Admin<S,E>

Returns:

the end step of the traversal

clone

public DefaultTraversal<S,E> clone()

Description copied from interface: Traversal.Admin

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

Specified by:

clone in interface Traversal.Admin<S,E>

Overrides:

clone in class Object

Returns:

The cloned traversal

isLocked

public boolean isLocked()

Description copied from interface: Traversal.Admin

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

Specified by:

isLocked in interface Traversal.Admin<S,E>

Returns:

whether the traversal is locked

setSideEffects

public void setSideEffects(TraversalSideEffects sideEffects)

Description copied from interface: Traversal.Admin

Set the TraversalSideEffects of this traversal.

Specified by:

setSideEffects in interface Traversal.Admin<S,E>

Parameters:

sideEffects - the sideEffects to set for this traversal.

getSideEffects

public TraversalSideEffects getSideEffects()

Description copied from interface: Traversal.Admin

Get the TraversalSideEffects associated with the traversal.

Specified by:

getSideEffects in interface Traversal.Admin<S,E>

Returns:

The traversal sideEffects

setStrategies

public void setStrategies(TraversalStrategies strategies)

Description copied from interface: Traversal.Admin

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

Specified by:

setStrategies in interface Traversal.Admin<S,E>

Parameters:

strategies - the strategies to use on this traversal

getStrategies

public TraversalStrategies getStrategies()

Description copied from interface: Traversal.Admin

Get the TraversalStrategies associated with this traversal.

Specified by:

getStrategies in interface Traversal.Admin<S,E>

Returns:

the strategies associated with this traversal

addStep

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

Description copied from interface: Traversal.Admin

Add a Step to an arbitrary point in the traversal.

Specified by:

addStep in interface Traversal.Admin<S,E>

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

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

Description copied from interface: Traversal.Admin

Remove a Step from the traversal.

Specified by:

removeStep in interface Traversal.Admin<S,E>

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

setParent

public void setParent(TraversalParent step)

Description copied from interface: Traversal.Admin

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.

Specified by:

setParent in interface Traversal.Admin<S,E>

Parameters:

step - the traversal holder parent step

getParent

public TraversalParent getParent()

Description copied from interface: Traversal.Admin

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.

Specified by:

getParent in interface Traversal.Admin<S,E>

Returns:

the traversal holder parent step

getGraph

public Optional<Graph> getGraph()

Specified by:

getGraph in interface Traversal.Admin<S,E>

setGraph

public void setGraph(Graph graph)

Specified by:

setGraph in interface Traversal.Admin<S,E>