Class OrderIterator

java.lang.Object

org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<BindingSet>

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

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

All Implemented Interfaces:

AutoCloseable, Iterator<BindingSet>, CloseableIteration<BindingSet>

public class OrderIterator
extends DelayedIteration<BindingSet>

Sorts the input and optionally applies limit and distinct.

Author:

James Leigh, Arjohn Kampman

Field Summary

Fields inherited from interface CloseableIteration

EMPTY_STATEMENT_ITERATION

Modifier and Type	Field	Description
static final EmptyIteration<Statement>	EMPTY_STATEMENT_ITERATION

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
protected CloseableIteration<BindingSet>	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()
protected void	onInputRowRead(BindingSet next)
protected void	onSortCompleted(long inputRows, long spillCount, long spillBytes)
protected void	onSpillToDisk(int spilledRows, long spilledBytes)
void	remove()	Calls the remove method of the underlying iteration.

Methods inherited from class DelayedIteration

hasNext, next

Modifier and Type	Method	Description
boolean	hasNext()	Calls the hasNext method of the underlying iteration.
BindingSet	next()	Calls the next method of the underlying iteration.

Methods inherited from class AbstractCloseableIteration

close, isClosed

Modifier and Type	Method	Description
final void	close()	Calls AbstractCloseableIteration.handleClose() upon first call and makes sure the resource closures are only executed once.
final boolean	isClosed()	Checks whether this CloseableIteration has been closed.

Methods inherited from class Object

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

Methods inherited from interface CloseableIteration

stream

Modifier and Type	Method	Description
default Stream<BindingSet>	stream()	Convert the results to a Java 8 Stream.

Methods inherited from interface Iterator

forEachRemaining

Constructor Details

OrderIterator

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

OrderIterator

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

OrderIterator

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

Method Details

createIteration

protected CloseableIteration<BindingSet> 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>

Throws:

QueryEvaluationException

increment

protected void increment()
                  throws QueryEvaluationException

Throws:

QueryEvaluationException

onInputRowRead

protected void onInputRowRead(BindingSet next)
                       throws QueryEvaluationException

Throws:

QueryEvaluationException

onSpillToDisk

protected void onSpillToDisk(int spilledRows,
 long spilledBytes)
                      throws QueryEvaluationException

Throws:

QueryEvaluationException

onSortCompleted

protected void onSortCompleted(long inputRows,
 long spillCount,
 long spillBytes)

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 Iterator<BindingSet>

Overrides:

remove in class DelayedIteration<BindingSet>

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>

Throws:

QueryEvaluationException