org.openrdf.query.algebra.evaluation.iterator

Class OrderIterator

java.lang.Object

info.aduna.iteration.CloseableIterationBase<E,X>

info.aduna.iteration.DelayedIteration<BindingSet,QueryEvaluationException>

org.openrdf.query.algebra.evaluation.iterator.OrderIterator

All Implemented Interfaces:

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)

Method Summary

Modifier and Type	Method and Description
protected boolean	add(BindingSet next, Collection<BindingSet> list)
protected Iteration<BindingSet,QueryEvaluationException>	createIteration() Creates the iteration that should be iterated over.
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 List<BindingSet>	makeList()
protected NavigableMap<BindingSet,Collection<BindingSet>>	makeOrderedMap(Comparator<BindingSet> comparator2)
protected Set<BindingSet>	makeOrderedSet() This is used when distinct is set too true.
protected Collection<BindingSet>	put(Map<BindingSet,Collection<BindingSet>> map, BindingSet next, Collection<BindingSet> list)
void	remove() Calls the remove method of the underlying iteration.
protected Collection<BindingSet>	remove(NavigableMap<BindingSet,Collection<BindingSet>> map, BindingSet lastKey)
protected void	removeLast(Collection<BindingSet> lastResults)

Methods inherited from class info.aduna.iteration.DelayedIteration

hasNext, next

Methods inherited from class info.aduna.iteration.CloseableIterationBase

close, isClosed

Methods inherited from class java.lang.Object

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

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)

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

makeList

protected List<BindingSet> makeList()

makeOrderedSet

protected Set<BindingSet> makeOrderedSet()

This is used when distinct is set too true.

Returns:

a new Set may be store specific.

removeLast

protected void removeLast(Collection<BindingSet> lastResults)

remove

protected Collection<BindingSet> remove(NavigableMap<BindingSet,Collection<BindingSet>> map,
                                        BindingSet lastKey)

add

protected boolean add(BindingSet next,
                      Collection<BindingSet> list)
               throws QueryEvaluationException

Throws:

QueryEvaluationException

put

protected Collection<BindingSet> put(Map<BindingSet,Collection<BindingSet>> map,
                                     BindingSet next,
                                     Collection<BindingSet> list)
                              throws QueryEvaluationException

Throws:

QueryEvaluationException

makeOrderedMap

protected NavigableMap<BindingSet,Collection<BindingSet>> makeOrderedMap(Comparator<BindingSet> comparator2)

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