org.eclipse.rdf4j.query.algebra.evaluation.iterator

Class OrderIterator

java.lang.Object

org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E,X>

org.eclipse.rdf4j.common.iteration.DelayedIteration<BindingSet,QueryEvaluationException>

org.eclipse.rdf4j.query.algebra.evaluation.iterator.OrderIterator

All Implemented Interfaces:

AutoCloseable, CloseableIteration<BindingSet,QueryEvaluationException>, Iteration<BindingSet,QueryEvaluationException>

Direct Known Subclasses:

LimitedSizeOrderIteration

public class OrderIterator
extends DelayedIteration<BindingSet,QueryEvaluationException>

Sorts the input and optionally applies limit and distinct.

Author:

James Leigh, Arjohn Kampman

Constructor Summary

Constructors

Constructor and Description
OrderIterator(CloseableIteration<BindingSet,QueryEvaluationException> iter, Comparator<BindingSet> comparator)
OrderIterator(CloseableIteration<BindingSet,QueryEvaluationException> iter, Comparator<BindingSet> comparator, long limit, boolean distinct)
OrderIterator(CloseableIteration<BindingSet,QueryEvaluationException> iter, Comparator<BindingSet> comparator, long limit, boolean distinct, long iterationSyncThreshold)

Method Summary

Modifier and Type	Method and Description
protected Iteration<BindingSet,QueryEvaluationException>	createIteration() Creates the iteration that should be iterated over.
protected void	decrement(int amount)
protected void	handleClose() Closes this iteration as well as the underlying iteration if it has already been created and happens to be a CloseableIteration.
protected void	increment()
void	remove() Calls the remove method of the underlying iteration.

Methods inherited from class org.eclipse.rdf4j.common.iteration.DelayedIteration

hasNext, next

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, toString, wait, wait, wait

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

stream

Constructor Detail

OrderIterator

public OrderIterator(CloseableIteration<BindingSet,QueryEvaluationException> iter,
                     Comparator<BindingSet> comparator)

OrderIterator

public OrderIterator(CloseableIteration<BindingSet,QueryEvaluationException> iter,
                     Comparator<BindingSet> comparator,
                     long limit,
                     boolean distinct)

OrderIterator

public OrderIterator(CloseableIteration<BindingSet,QueryEvaluationException> iter,
                     Comparator<BindingSet> comparator,
                     long limit,
                     boolean distinct,
                     long iterationSyncThreshold)

Method Detail

createIteration

protected Iteration<BindingSet,QueryEvaluationException> createIteration()
                                                                  throws QueryEvaluationException

Description copied from class: DelayedIteration

Creates the iteration that should be iterated over. This method is called only once, when the iteration is first needed.

Specified by:

createIteration in class DelayedIteration<BindingSet,QueryEvaluationException>

Throws:

QueryEvaluationException

increment

protected void increment()
                  throws QueryEvaluationException

Throws:

QueryEvaluationException

decrement

protected void decrement(int amount)
                  throws QueryEvaluationException

Throws:

QueryEvaluationException

remove

public void remove()
            throws QueryEvaluationException

Description copied from class: DelayedIteration

Calls the remove method of the underlying iteration.

Specified by:

remove in interface Iteration<BindingSet,QueryEvaluationException>

Overrides:

remove in class DelayedIteration<BindingSet,QueryEvaluationException>

Throws:

QueryEvaluationException

handleClose

protected void handleClose()
                    throws QueryEvaluationException

Description copied from class: DelayedIteration

Closes this iteration as well as the underlying iteration if it has already been created and happens to be a CloseableIteration.

Overrides:

handleClose in class DelayedIteration<BindingSet,QueryEvaluationException>

Throws:

QueryEvaluationException