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

Class LazyBarrierStrategy

java.lang.Object

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

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

All Implemented Interfaces:

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

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

LazyBarrierStrategy is an OLTP-only strategy that automatically inserts a NoOpBarrierStep after every FlatMapStep if neither path-tracking nor partial path-tracking is required, and the next step is not the traversal's last step or a Barrier. NoOpBarrierSteps allow traversers to be bulked, thus this strategy is meant to reduce memory requirements and improve the overall query performance.

Author:

Marko A. Rodriguez (http://markorodriguez.com)

See Also:

• Serialized Form

Example:

 __.out().bothE().count()      // is replaced by __.out().barrier(2500).bothE().count()
 __.both().both().valueMap()   // is replaced by __.both().barrier(2500).both().barrier(2500).valueMap()
 

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

Modifier and Type	Field	Description
static final String	BARRIER_COPY_LABELS
static final String	BARRIER_PLACEHOLDER
protected static final int	MAX_BARRIER_SIZE

Method Summary

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

getConfiguration

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

applyPost, compareTo, getTraversalCategory

Field Details

BARRIER_PLACEHOLDER

public static final String BARRIER_PLACEHOLDER

BARRIER_COPY_LABELS

public static final String BARRIER_COPY_LABELS

MAX_BARRIER_SIZE

protected static final int MAX_BARRIER_SIZE

See Also:

• Constant Field Values

Method Details

apply

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

Description copied from interface: TraversalStrategy

The transformation the strategy applies to the 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 LazyBarrierStrategy instance()