Package org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect

Class AggregateStep<S>

java.lang.Object
org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep<S,S>
org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect.AggregateStep<S>
All Implemented Interfaces:
Serializable, AutoCloseable, Cloneable, Iterator<Traverser.Admin<S>>, Step<S,S>, Barrier<TraverserSet<S>>, ByModulating, Generating<Collection,Collection>, LocalBarrier<S>, MemoryComputing<TraverserSet<S>>, PopContaining, SideEffectCapable<Collection,Collection>, TraversalParent
public final class AggregateStep<S> extends AbstractStep<S,S> implements SideEffectCapable<Collection,Collection>, TraversalParent, ByModulating, LocalBarrier<S>
Author:
Marko A. Rodriguez (http://markorodriguez.com)
See Also:

  • Constructor Details

  • Method Details

    • getSideEffectKey

      public String getSideEffectKey()
      Description copied from interface: SideEffectCapable
      The side-effect key of the step.
      Specified by:
      getSideEffectKey in interface SideEffectCapable<Collection,Collection>
      Returns:
      the side-effect key

    • toString

      public String toString()
      Overrides:
      toString in class AbstractStep<S,S>

    • modulateBy

      public void modulateBy(Traversal.Admin<?,?> aggregateTraversal)
      Specified by:
      modulateBy in interface ByModulating

    • replaceLocalChild

      public void replaceLocalChild(Traversal.Admin<?,?> oldTraversal, Traversal.Admin<?,?> newTraversal)
      Specified by:
      replaceLocalChild in interface TraversalParent

    • getLocalChildren

      public List<Traversal.Admin<S,Object>> getLocalChildren()
      Description copied from interface: TraversalParent
      Gets a list of all "local" child traversals for this step. A "local" traversal is one which is evaluated independently for each incoming traverser to the parent step. This is typically used in cases where the child is used to process or augment each traverser individually. See LocalStep or ByModulating as examples.
      Specified by:
      getLocalChildren in interface TraversalParent

    • getRequirements

      public Set<TraverserRequirement> getRequirements()
      Description copied from interface: Step
      Provide the necessary TraverserRequirement that must be met by the traverser in order for the step to function properly. The provided default implements returns an empty set.
      Specified by:
      getRequirements in interface Step<S,S>
      Returns:
      the set of requirements

    • clone

      public AggregateStep<S> clone()
      Description copied from interface: Step
      Cloning is used to duplicate steps for the purpose of traversal optimization and OLTP replication. When cloning a step, it is important that the steps, the cloned step is equivalent to the state of the step when Step.reset() is called. Moreover, the previous and next steps should be set to EmptyStep.
      Specified by:
      clone in interface Step<S,S>
      Overrides:
      clone in class AbstractStep<S,S>
      Returns:
      The cloned step

    • setTraversal

      public void setTraversal(Traversal.Admin<?,?> parentTraversal)
      Description copied from interface: Step
      Set the Traversal that this step is contained within.
      Specified by:
      setTraversal in interface Step<S,S>
      Overrides:
      setTraversal in class AbstractStep<S,S>
      Parameters:
      parentTraversal - the new traversal for this step

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class AbstractStep<S,S>

    • processNextStart

      protected Traverser.Admin<S> processNextStart()
      Specified by:
      processNextStart in class AbstractStep<S,S>

    • processAllStarts

      public void processAllStarts()
      Description copied from interface: Barrier
      Process all left traversers by do not yield the resultant output. This method is useful for steps like ReducingBarrierStep, where traversers can be processed "on the fly" and thus, reduce memory consumption.
      Specified by:
      processAllStarts in interface Barrier<S>

    • hasNextBarrier

      public boolean hasNextBarrier()
      Description copied from interface: Barrier
      Whether or not the step has an accessible barrier.
      Specified by:
      hasNextBarrier in interface Barrier<S>
      Returns:
      whether a barrier exists or not

    • nextBarrier

      public TraverserSet<S> nextBarrier() throws NoSuchElementException
      Description copied from interface: Barrier
      Get the next barrier within this step. Barriers from parallel steps can be the be merged to create a single step with merge barriers.
      Specified by:
      nextBarrier in interface Barrier<S>
      Returns:
      the next barrier of the step
      Throws:
      NoSuchElementException

    • addBarrier

      public void addBarrier(TraverserSet<S> barrier)
      Description copied from interface: Barrier
      Add a barrier to the step. This typically happens when multiple parallel barriers need to become one barrier at a single step.
      Specified by:
      addBarrier in interface Barrier<S>
      Parameters:
      barrier - the barrier to merge in

    • reset

      public void reset()
      Description copied from interface: Step
      Reset the state of the step such that it has no incoming starts. Internal states are to be reset, but any sideEffect data structures are not to be recreated.
      Specified by:
      reset in interface Step<S,S>
      Overrides:
      reset in class AbstractStep<S,S>