org.janusgraph.graphdb.tinkerpop.optimize

Class JanusGraphTraversalUtil

java.lang.Object

org.janusgraph.graphdb.tinkerpop.optimize.JanusGraphTraversalUtil

public class JanusGraphTraversalUtil
extends Object

Author:

Matthias Broecheler (me@matthiasb.com)

Constructor Summary

Constructors

Constructor and Description
JanusGraphTraversalUtil()

Method Summary

Modifier and Type	Method and Description
static List<org.apache.tinkerpop.gremlin.process.traversal.Step>	getAllMultiQueryPositionsForMultiQueriable(org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> multiQueriable) Backtraces the traversal for the position where a MultiQueriable step would expect its corresponding JanusGraphMultiQueryStep(s).
static StandardJanusGraph	getJanusGraph(org.apache.tinkerpop.gremlin.process.traversal.Traversal.Admin<?,?> traversal)
static Optional<StandardJanusGraphTx>	getJanusGraphTx(org.apache.tinkerpop.gremlin.process.traversal.Traversal.Admin<?,?> traversal)
static JanusGraphVertex	getJanusGraphVertex(org.apache.tinkerpop.gremlin.structure.Element v)
static JanusGraphVertex	getJanusGraphVertex(org.apache.tinkerpop.gremlin.process.traversal.Traverser<? extends org.apache.tinkerpop.gremlin.structure.Element> traverser)
static Optional<org.apache.tinkerpop.gremlin.process.traversal.Step>	getLocalMultiQueryPositionForStep(org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> step) For a MultiQuery compatible step, this method searches the correct position in the step's traversal at which a JanusGraphMultiQueryStep should be inserted.
static org.apache.tinkerpop.gremlin.process.traversal.Step	getNextNonIdentityStep(org.apache.tinkerpop.gremlin.process.traversal.Step start)
static <S> Optional<S>	getPreviousStepOfClass(Class<S> stepClass, org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> start) Starting at the given step, this method searches the traversal backwards to find the most recent step which matches the given class.
static List<org.apache.tinkerpop.gremlin.process.traversal.Step>	getSteps(Predicate<org.apache.tinkerpop.gremlin.process.traversal.Step> predicate, org.apache.tinkerpop.gremlin.process.traversal.Traversal.Admin<?,?> traversal) Returns a list of steps from the traversal, which match a given predicate.
static JanusGraphTransaction	getTx(org.apache.tinkerpop.gremlin.process.traversal.Traversal.Admin<?,?> traversal)
static boolean	isEdgeReturnStep(JanusGraphVertexStep vertexStep)
static boolean	isLegalMultiQueryPosition(org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> step) This method closely matches the behavior implemented in LazyBarrierStrategy which ensures that no NoOpBarrierSteps are inserted if path labels are required.
static boolean	isMultiQueryCompatibleParent(org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> step) Checks whether this step is a traversal parent for which a preceding JanusGraphMultiQueryStep can have a positive impact on the step's child traversals.
static boolean	isMultiQueryCompatibleStep(org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> step) Checks whether a step can profit of a preceding JanusGraphMultiQueryStep.
static boolean	isVertexReturnStep(JanusGraphVertexStep vertexStep)

Methods inherited from class java.lang.Object

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

Constructor Detail

JanusGraphTraversalUtil

public JanusGraphTraversalUtil()

Method Detail

getJanusGraph

public static StandardJanusGraph getJanusGraph(org.apache.tinkerpop.gremlin.process.traversal.Traversal.Admin<?,?> traversal)

getJanusGraphTx

public static Optional<StandardJanusGraphTx> getJanusGraphTx(org.apache.tinkerpop.gremlin.process.traversal.Traversal.Admin<?,?> traversal)

getJanusGraphVertex

public static JanusGraphVertex getJanusGraphVertex(org.apache.tinkerpop.gremlin.structure.Element v)

getJanusGraphVertex

public static JanusGraphVertex getJanusGraphVertex(org.apache.tinkerpop.gremlin.process.traversal.Traverser<? extends org.apache.tinkerpop.gremlin.structure.Element> traverser)

isEdgeReturnStep

public static boolean isEdgeReturnStep(JanusGraphVertexStep vertexStep)

isVertexReturnStep

public static boolean isVertexReturnStep(JanusGraphVertexStep vertexStep)

getNextNonIdentityStep

public static org.apache.tinkerpop.gremlin.process.traversal.Step getNextNonIdentityStep(org.apache.tinkerpop.gremlin.process.traversal.Step start)

getTx

public static JanusGraphTransaction getTx(org.apache.tinkerpop.gremlin.process.traversal.Traversal.Admin<?,?> traversal)

getAllMultiQueryPositionsForMultiQueriable

public static List<org.apache.tinkerpop.gremlin.process.traversal.Step> getAllMultiQueryPositionsForMultiQueriable(org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> multiQueriable)

Backtraces the traversal for the position where a MultiQueriable step would expect its corresponding JanusGraphMultiQueryStep(s). In case of MultiQueriables nested in RepeatSteps, multiple destinations are returned.

Parameters:

multiQueriable - The MultiQuery compatible step whose MultiQueryStep positions shall be searched.

Returns:

The step before which the MultiQueryStep is located or expected.

getLocalMultiQueryPositionForStep

public static Optional<org.apache.tinkerpop.gremlin.process.traversal.Step> getLocalMultiQueryPositionForStep(org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> step)

For a MultiQuery compatible step, this method searches the correct position in the step's traversal at which a JanusGraphMultiQueryStep should be inserted. Only the traversal of the given step is considered, parent and child traversals are not taken into account.

Parameters:

step - The MultiQuery compatible step.

Returns:

The step before which a JanusGraphMultiQueryStep should be inserted.

See Also:

JanusGraphMultiQueryStep

isMultiQueryCompatibleParent

public static boolean isMultiQueryCompatibleParent(org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> step)

Checks whether this step is a traversal parent for which a preceding JanusGraphMultiQueryStep can have a positive impact on the step's child traversals.

Parameters:

step - The step to be checked.

Returns:

true if the step's child traversals can possibly benefit of a preceding JanusGraphMultiQueryStep, otherwise false.

isMultiQueryCompatibleStep

public static boolean isMultiQueryCompatibleStep(org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> step)

Checks whether a step can profit of a preceding JanusGraphMultiQueryStep.

Parameters:

step - The step for which the condition is checked.

Returns:

true if the step is either a MultiQueriable or is a MultiQuery compatible parent step.

See Also:

MultiQueriable

isLegalMultiQueryPosition

public static boolean isLegalMultiQueryPosition(org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> step)

This method closely matches the behavior implemented in LazyBarrierStrategy which ensures that no NoOpBarrierSteps are inserted if path labels are required. Since the same limitation applies to JanusGraphMultiQuerySteps, the definition of legal positions for this step is the same.

Parameters:

step - The step which follows the JanusGraphMultiQueryStep to be inserted.

Returns:

true if no path labels are required for this position, otherwise false.

See Also:

LazyBarrierStrategy

getPreviousStepOfClass

public static <S> Optional<S> getPreviousStepOfClass(Class<S> stepClass,
                                                     org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> start)

Starting at the given step, this method searches the traversal backwards to find the most recent step which matches the given class. Only the traversal of the given step is scanned and parent or child traversals are not taken into account.

Type Parameters:

S - The class of the requested step.

Parameters:

stepClass - The class of the requested step.

start - The step from which the search is started.

Returns:

An Optional which contains the requested step if it was found.

getSteps

public static List<org.apache.tinkerpop.gremlin.process.traversal.Step> getSteps(Predicate<org.apache.tinkerpop.gremlin.process.traversal.Step> predicate,
                                                                                 org.apache.tinkerpop.gremlin.process.traversal.Traversal.Admin<?,?> traversal)

Returns a list of steps from the traversal, which match a given predicate.

Parameters:

predicate - Whether or not a step should be in the returned list.

traversal - The traversal whose steps should be used.

Returns:

The list of matching steps.