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 org.apache.tinkerpop.gremlin.process.traversal.Step<?,?>	findMostOuterEligibleStart(org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> step) In case `step` can be considered as eligible start step then this method returns the most outer eligible parent step.
static MultiQueryPositions	getAllMultiQueryPositionsForMultiQueriable(MultiQueriable<?,?> multiQueriable, boolean multiNestedRepeatEligible, boolean multiNestedRepeatNextIterationEligible) Backtraces the traversal for the position where a MultiQueriable step would expect its corresponding JanusGraphMultiQueryStep(s).
static Optional<org.apache.tinkerpop.gremlin.process.traversal.Step>	getEndMultiQueryPosition(org.apache.tinkerpop.gremlin.process.traversal.Traversal.Admin repeatTraversal) Returns multi query position for the end of the traversal.
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 Optional<Integer>	getLocalNonMultiQueryProvidedBatchSize(MultiQueriable<?,?> multiQueriable) Returns local barrier step size if that barrier step is not generated by JanusGraphMultiQueryStep.
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)
static boolean	isStartStep(org.apache.tinkerpop.gremlin.process.traversal.Step<?,?> step) Checks if the provided step is the start step of its Traversal skipping any `IdentityStep`, `NoOpBarrierStep`, `SideEffectStep`, `ProfileStep`, and `JanusGraphMultiQueryStep` steps at the beginning.
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)

findMostOuterEligibleStart

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

In case `step` can be considered as eligible start step then this method returns the most outer eligible parent step. The most outer eligible parent for the provided `step` is the one which is directly or indirectly includes the provided `step` and satisfies the following criteria:
- It includes the maximum number of nested eligible parents for the provided `step`. - All the nested parents, including the provided `step` must be considered as `start` steps of their respective traversals. - Each such nested parent of the provided `step` must be parentToChildProxyStep (determined by `isParentToChildProxyStep(nextStep)` method).
In case `step` don't have any eligible parents then the provided `step` will be returned.

isMultiQueryCompatibleParent

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

getAllMultiQueryPositionsForMultiQueriable

public static MultiQueryPositions getAllMultiQueryPositionsForMultiQueriable(MultiQueriable<?,?> multiQueriable,
                                                                             boolean multiNestedRepeatEligible,
                                                                             boolean multiNestedRepeatNextIterationEligible)

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.

getEndMultiQueryPosition

public static Optional<org.apache.tinkerpop.gremlin.process.traversal.Step> getEndMultiQueryPosition(org.apache.tinkerpop.gremlin.process.traversal.Traversal.Admin repeatTraversal)

Returns multi query position for the end of the traversal. This can be useful in case by the end of the traversal, vertices should be registered for prefetching in some other places.

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

getLocalNonMultiQueryProvidedBatchSize

public static Optional<Integer> getLocalNonMultiQueryProvidedBatchSize(MultiQueriable<?,?> multiQueriable)

Returns local barrier step size if that barrier step is not generated by JanusGraphMultiQueryStep.

isStartStep

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

Checks if the provided step is the start step of its Traversal skipping any `IdentityStep`, `NoOpBarrierStep`, `SideEffectStep`, `ProfileStep`, and `JanusGraphMultiQueryStep` steps at the beginning.

Parameters:

step - Step to check.

Returns:

`true` if the step can be considered as the start of its traversal. `false` otherwise.

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.