org.apache.tinkerpop.gremlin.process.traversal.strategy.optimization

Class AdjacentToIncidentStrategy

java.lang.Object

org.apache.tinkerpop.gremlin.process.traversal.strategy.AbstractTraversalStrategy<TraversalStrategy.OptimizationStrategy>

org.apache.tinkerpop.gremlin.process.traversal.strategy.optimization.AdjacentToIncidentStrategy

All Implemented Interfaces:

Serializable, Comparable<Class<? extends TraversalStrategy>>, TraversalStrategy<TraversalStrategy.OptimizationStrategy>, TraversalStrategy.OptimizationStrategy

public final class AdjacentToIncidentStrategy
extends AbstractTraversalStrategy<TraversalStrategy.OptimizationStrategy>
implements TraversalStrategy.OptimizationStrategy

This strategy looks for vertex- and value-emitting steps followed by a CountGlobalStep and replaces the pattern with an edge- or property-emitting step followed by a CountGlobalStep. Furthermore, if a vertex- or value-emitting step is the last step in a .has(traversal), .and(traversal, ...) or .or(traversal, ...) child traversal, it is replaced by an appropriate edge- or property-emitting step. Performing this replacement removes situations where the more expensive trip to an adjacent graph element (e.g. the vertex on the other side of an edge) can be satisfied by trips to incident graph elements (e.g. just the edge itself).

Author:

Daniel Kuppitz (http://gremlin.guru)

See Also:

Serialized Form

Example:

 __.out().count()            // is replaced by __.outE().count()
 __.in().limit(3).count()    // is replaced by __.inE().limit(3).count()
 __.values("name").count()   // is replaced by __.properties("name").count()
 __.where(__.out())          // is replaced by __.where(__.outE())
 __.where(__.values())       // is replaced by __.where(__.properties())
 __.and(__.in(), __.out())   // is replaced by __.and(__.inE(), __.outE())
 

Nested Class Summary

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

TraversalStrategy.DecorationStrategy, TraversalStrategy.FinalizationStrategy, TraversalStrategy.OptimizationStrategy, TraversalStrategy.ProviderOptimizationStrategy, TraversalStrategy.VerificationStrategy

Field Summary

Fields inherited from interface org.apache.tinkerpop.gremlin.process.traversal.TraversalStrategy

STRATEGY

Method Summary

Modifier and Type	Method and Description
void	apply(Traversal.Admin<?,?> traversal)
Set<Class<? extends TraversalStrategy.OptimizationStrategy>>	applyPrior() The set of strategies that must be executed before this strategy is executed.
static AdjacentToIncidentStrategy	instance()

Methods inherited from class org.apache.tinkerpop.gremlin.process.traversal.strategy.AbstractTraversalStrategy

equals, hashCode, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.TraversalStrategy.OptimizationStrategy

compareTo, getTraversalCategory

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

applyPost, getConfiguration

Method Detail

apply

public void apply(Traversal.Admin<?,?> traversal)

Specified by:

apply in interface TraversalStrategy<TraversalStrategy.OptimizationStrategy>

applyPrior

public Set<Class<? extends TraversalStrategy.OptimizationStrategy>> applyPrior()

Description copied from interface: TraversalStrategy

The set of strategies that must be executed before this strategy is executed. If there are no ordering requirements, the default implementation returns an empty set.

Specified by:

applyPrior in interface TraversalStrategy<TraversalStrategy.OptimizationStrategy>

Returns:

the set of strategies that must be executed prior to this one.

instance

public static AdjacentToIncidentStrategy instance()