Package org.eclipse.rdf4j.sail.federation.evaluation

## Class ParallelJoinCursor

- java.lang.Object
- - org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E,​X>
  - - org.eclipse.rdf4j.common.iteration.LookAheadIteration<BindingSet,​QueryEvaluationException>
    - - org.eclipse.rdf4j.sail.federation.evaluation.ParallelJoinCursor

- All Implemented Interfaces:
    `AutoCloseable`, `Runnable`, `CloseableIteration<BindingSet,​QueryEvaluationException>`, `Iteration<BindingSet,​QueryEvaluationException>`

      public class ParallelJoinCursor
      extends LookAheadIteration<BindingSet,​QueryEvaluationException>
      implements Runnable

  Iterate the left side and evaluate the right side in separate thread, only iterate the right side in the controlling thread.
  Author:
    James Leigh

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `ParallelJoinCursor​(EvaluationStrategy strategy, CloseableIteration<BindingSet,​QueryEvaluationException> leftIter, TupleExpr rightArg)` |

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `BindingSet` | `getNextElement()` | Gets the next element.
    `void` | `handleClose()` | Called by `AbstractCloseableIteration.close()` when it is called for the first time.
    `void` | `run()` |
    `String` | `toString()` |

    - ### Methods inherited from class org.eclipse.rdf4j.common.iteration.LookAheadIteration

      `hasNext, next, remove`

    - ### Methods inherited from class org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration

      `close, isClosed`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

    - ### Methods inherited from interface org.eclipse.rdf4j.common.iteration.Iteration

      `stream`

- - ### Constructor Detail

    - #### ParallelJoinCursor

          public ParallelJoinCursor​(EvaluationStrategy strategy,
                                    CloseableIteration<BindingSet,​QueryEvaluationException> leftIter,
                                    TupleExpr rightArg)
                             throws QueryEvaluationException

      Throws:
        `QueryEvaluationException`

  - ### Method Detail

    - #### run

          public void run()

      Specified by:
        `run` in interface `Runnable`

    - #### getNextElement

          public BindingSet getNextElement()
                                    throws QueryEvaluationException

      Description copied from class: `LookAheadIteration`
      Gets the next element. Subclasses should implement this method so that it returns the next element.
      Specified by:
        `getNextElement` in class `LookAheadIteration<BindingSet,​QueryEvaluationException>`
      Returns:
        The next element, or null if no more elements are available.
      Throws:
        `QueryEvaluationException`

    - #### handleClose

          public void handleClose()
                           throws QueryEvaluationException

      Description copied from class: `AbstractCloseableIteration`
      Called by `AbstractCloseableIteration.close()` when it is called for the first time. This method is only called once on each iteration. By default, this method does nothing.
      Overrides:
        `handleClose` in class `LookAheadIteration<BindingSet,​QueryEvaluationException>`
      Throws:
        `QueryEvaluationException`

    - #### toString

          public String toString()

      Overrides:
        `toString` in class `Object`