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

Interface Traverser.Admin<T>

All Superinterfaces:
org.apache.tinkerpop.gremlin.structure.util.Attachable<T>, Cloneable, Comparable<Traverser<T>>, Serializable, Traverser<T>
Enclosing interface:
Traverser<T>
public static interface Traverser.Admin<T> extends Traverser<T>, org.apache.tinkerpop.gremlin.structure.util.Attachable<T>
The methods in System.Traverser are useful to underlying Step and Traversal implementations. They should not be accessed by the user during lambda-based manipulations.

  • Nested Class Summary

    Nested classes/interfaces inherited from interface org.apache.tinkerpop.gremlin.structure.util.Attachable

    org.apache.tinkerpop.gremlin.structure.util.Attachable.Exceptions, org.apache.tinkerpop.gremlin.structure.util.Attachable.Method

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

    Traverser.Admin<T>

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    HALT
     

    Fields inherited from interface org.apache.tinkerpop.gremlin.structure.util.Attachable

    logger

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    addLabels(Set<String> labels)
     
    T
    attach(Function<org.apache.tinkerpop.gremlin.structure.util.Attachable<T>,T> method)
    Regenerate the detached traverser given its location at a particular vertex.
    Traverser.Admin<T>
    detach()
    Prepare the traverser for migration across a JVM boundary.
    void
    dropLabels(Set<String> labels)
    Drop all path information associated with specified labels.
    void
    dropPath()
    Drop the path of the traverser.
    default Set<String>
    getLoopNames()
    If this traverser supports loops then return the loop names if any.
    TraversalSideEffects
    getSideEffects()
    Get the sideEffects associated with the traversal of the traverser.
    String
    getStepId()
    Get the step id of where the traverser is located.
    Set<String>
    getTags()
    Get the tags associated with the traverser.
    default void
    incrLoops()
    Increment the number of times the traverser has gone through a looping section of traversal.
    default void
    initialiseLoops(String stepLabel, String loopName)
    Initialise a loop by setting up the looping construct.
    default boolean
    isHalted()
    If the traverser has "no future" then it is done with its lifecycle.
    void
    keepLabels(Set<String> labels)
    Drop all path information not associated with specified labels.
    void
    merge(Traverser.Admin<?> other)
    When two traversers are have equality with each other, then they can be merged.
    default void
    resetLoops()
    Set the number of times the traverser has gone through a loop back to 0.
    void
    set(T t)
    Set the current object location of the traverser.
    void
    setBulk(long count)
    Set the number of traversers represented by this traverser.
    void
    setSideEffects(TraversalSideEffects sideEffects)
    Set the sideEffects of the Traversal.
    void
    setStepId(String stepId)
    Set the step id of where the traverser is located.
    Traverser.Admin<T>
    split()
    Generate a sibling traverser of the current traverser with a full copy of all state within the sibling.
    <R> Traverser.Admin<R>
    split(R r, Step<T,R> step)
    Generate a child traverser of the current traverser for current as step and new object location.

    Methods inherited from interface org.apache.tinkerpop.gremlin.structure.util.Attachable

    get

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

    asAdmin, bulk, clone, compareTo, get, loops, loops, path, path, path, sack, sack, sideEffects, sideEffects

  • Field Details

  • Method Details

    • merge

      void merge(Traverser.Admin<?> other)
      When two traversers are have equality with each other, then they can be merged. This method is used to merge the traversers into a single traverser. This is used for optimization where instead of enumerating all traversers, they can be counted.
      Parameters:
      other - the other traverser to merge into this traverser. Once merged, the other can be garbage collected.

    • split

      <R> Traverser.Admin<R> split(R r, Step<T,R> step)
      Generate a child traverser of the current traverser for current as step and new object location. The child has the path history, future, and loop information of the parent. The child extends that path history with the current as and provided R-object.
      Type Parameters:
      R - The current object type of the child
      Parameters:
      r - The current object of the child
      step - The step yielding the split
      Returns:
      The split traverser

    • split

      Traverser.Admin<T> split()
      Generate a sibling traverser of the current traverser with a full copy of all state within the sibling.
      Returns:
      The split traverser

    • addLabels

      void addLabels(Set<String> labels)

    • keepLabels

      void keepLabels(Set<String> labels)
      Drop all path information not associated with specified labels. This is an optimization method that allows a traverser to save memory and increase the likelihood of bulking.
      Parameters:
      labels - the labels to keep path information for.

    • dropLabels

      void dropLabels(Set<String> labels)
      Drop all path information associated with specified labels. This is an optimization method that allows a traverser to save memory and increase the likelihood of bulking.
      Parameters:
      labels - the labels to drop path information for.

    • dropPath

      void dropPath()
      Drop the path of the traverser. This is an optimization method that allows a traverser to save memory and increase the likelihood of bulking.

    • set

      void set(T t)
      Set the current object location of the traverser.
      Parameters:
      t - The current object of the traverser

    • initialiseLoops

      default void initialiseLoops(String stepLabel, String loopName)
      Initialise a loop by setting up the looping construct. The step label is important to create a stack of loop counters when within a nested context. If the provided label is not the same as the current label on the stack, add a new loop counter. The loopName can be used to refer to the loops counter via the LoopsStep
      Parameters:
      stepLabel - the label of the step that is being set-up.
      loopName - the user defined name for referencing the loop counter or null if not set

    • incrLoops

      default void incrLoops()
      Increment the number of times the traverser has gone through a looping section of traversal.

    • resetLoops

      default void resetLoops()
      Set the number of times the traverser has gone through a loop back to 0. When a traverser exits a looping construct, this method should be called. In a nested loop context, the highest stack loop counter should be removed.

    • getStepId

      String getStepId()
      Get the step id of where the traverser is located. This is typically used in multi-machine systems that require the movement of traversers between different traversal instances.
      Returns:
      The future step for the traverser

    • setStepId

      void setStepId(String stepId)
      Set the step id of where the traverser is located. If the future is HALT, then isHalted() is true.
      Parameters:
      stepId - The future step of the traverser

    • isHalted

      default boolean isHalted()
      If the traverser has "no future" then it is done with its lifecycle. This does not mean that the traverser is "dead," only that it has successfully passed through a Traversal.
      Returns:
      Whether the traverser is done executing or not

    • setBulk

      void setBulk(long count)
      Set the number of traversers represented by this traverser.
      Parameters:
      count - the number of traversers

    • detach

      Traverser.Admin<T> detach()
      Prepare the traverser for migration across a JVM boundary.
      Returns:
      The deflated traverser

    • attach

      T attach(Function<org.apache.tinkerpop.gremlin.structure.util.Attachable<T>,T> method)
      Regenerate the detached traverser given its location at a particular vertex.
      Specified by:
      attach in interface org.apache.tinkerpop.gremlin.structure.util.Attachable<T>
      Parameters:
      method - The method by which to attach a Traverser to an vertex.
      Returns:
      The inflated traverser

    • setSideEffects

      void setSideEffects(TraversalSideEffects sideEffects)
      Set the sideEffects of the Traversal. Given that traversers can move between machines, it may be important to re-set this when the traverser crosses machine boundaries.
      Parameters:
      sideEffects - the sideEffects of the traversal.

    • getSideEffects

      TraversalSideEffects getSideEffects()
      Get the sideEffects associated with the traversal of the traverser.
      Returns:
      the traversal sideEffects of the traverser

    • getTags

      Set<String> getTags()
      Get the tags associated with the traverser. Tags are used to categorize historic behavior of a traverser. The returned set is mutable.
      Returns:
      the set of tags associated with the traverser.

    • getLoopNames

      default Set<String> getLoopNames()
      If this traverser supports loops then return the loop names if any.