Class FedXQueueCursor<T>

java.lang.Object

org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<CloseableIteration<T>>

org.eclipse.rdf4j.common.iteration.LookAheadIteration<CloseableIteration<T>>

org.eclipse.rdf4j.common.iteration.QueueIteration<CloseableIteration<T>, QueryEvaluationException>

org.eclipse.rdf4j.query.impl.QueueCursor<CloseableIteration<T>>

org.eclipse.rdf4j.federated.evaluation.concurrent.FedXQueueCursor<T>

Type Parameters:

T -

All Implemented Interfaces:

AutoCloseable, Iterator<CloseableIteration<T>>, CloseableIteration<CloseableIteration<T>>

public class FedXQueueCursor<T>
extends QueueCursor<CloseableIteration<T>>

Specialized variants of QueueCursor which avoids converting any exception if it is already of typeQueryEvaluationException.

Author:

Andreas Schwarte

Field Summary

Fields inherited from interface CloseableIteration

EMPTY_STATEMENT_ITERATION

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

Method Summary

Modifier and Type	Method	Description
protected QueryEvaluationException	convert(Exception e)	Converts an exception from the underlying iteration to an exception of type X.
static <T> FedXQueueCursor<T>	create(int capacity)
static <T> FedXQueueCursor<T>	create(int capacity, WeakReference<?> callerReference)
void	handleClose()	Called by AbstractCloseableIteration.close() when it is called for the first time.

Methods inherited from class QueueIteration

checkException, done, getNextElement, put, toss

Modifier and Type	Method	Description
void	checkException()
void	done()	Indicates the method QueueIteration.put(Object) will not be called in the queue anymore.
CloseableIteration<T>	getNextElement()	Returns the next item in the queue, which may be null, or throws an exception.
void	put(CloseableIteration<T> item)	Adds another item to the queue, blocking while the queue is full.
void	toss(Exception exception)	The next time LookAheadIteration.next() is called this exception will be thrown.

Methods inherited from class LookAheadIteration

hasNext, next, remove

Modifier and Type	Method	Description
final boolean	hasNext()
final CloseableIteration<T>	next()
void	remove()	Throws an UnsupportedOperationException.

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<CloseableIteration<T>>	stream()	Convert the results to a Java 8 Stream.

Methods inherited from interface Iterator

forEachRemaining

Method Details

create

public static <T> FedXQueueCursor<T> create(int capacity,
 WeakReference<?> callerReference)

create

public static <T> FedXQueueCursor<T> create(int capacity)

convert

protected QueryEvaluationException convert(Exception e)

Description copied from class: QueueIteration

Converts an exception from the underlying iteration to an exception of type X.

Overrides:

convert in class QueueCursor<CloseableIteration<T>>

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 QueueIteration<CloseableIteration<T>, QueryEvaluationException>

Throws:

QueryEvaluationException