Package org.eclipse.rdf4j.query.impl
Class QueueCursor<E>
- java.lang.Object
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- org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E,X>
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- org.eclipse.rdf4j.common.iteration.LookAheadIteration<E,T>
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- org.eclipse.rdf4j.common.iteration.QueueIteration<E,QueryEvaluationException>
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- org.eclipse.rdf4j.query.impl.QueueCursor<E>
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- All Implemented Interfaces:
AutoCloseable
,CloseableIteration<E,QueryEvaluationException>
,Iteration<E,QueryEvaluationException>
- Direct Known Subclasses:
FedXQueueCursor
,QueueCursor
public class QueueCursor<E> extends QueueIteration<E,QueryEvaluationException>
Makes working with a queue easier by adding the methodsQueueIteration.done()
andQueueIteration.toss(Exception)
and automatically converting the exception into a QueryEvaluationException with an appropriate stack trace.- Author:
- James Leigh
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Constructor Summary
Constructors Constructor Description QueueCursor(int capacity)
Creates an QueueCursor with the given (fixed) capacity and default access policy.QueueCursor(int capacity, boolean fair)
Creates an QueueCursor with the given (fixed) capacity and the specified access policy.QueueCursor(BlockingQueue<E> queue)
Creates an QueueCursor with the givenBlockingQueue
as its backing queue.
It may not be threadsafe to modify or access the givenBlockingQueue
from other locations.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected QueryEvaluationException
convert(Exception e)
Converts an exception from the underlying iteration to an exception of type X.-
Methods inherited from class org.eclipse.rdf4j.common.iteration.QueueIteration
checkException, done, getNextElement, handleClose, put, toss
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Methods inherited from class org.eclipse.rdf4j.common.iteration.LookAheadIteration
hasNext, next, remove
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Methods inherited from class org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration
close, isClosed
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Constructor Detail
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QueueCursor
public QueueCursor(int capacity)
Creates an QueueCursor with the given (fixed) capacity and default access policy.- Parameters:
capacity
- the capacity of this queue
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QueueCursor
public QueueCursor(int capacity, boolean fair)
Creates an QueueCursor with the given (fixed) capacity and the specified access policy.- Parameters:
capacity
- the capacity of this queuefair
- if true then queue accesses for threads blocked on insertion or removal, are processed in FIFO order; if false the access order is unspecified.
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QueueCursor
public QueueCursor(BlockingQueue<E> queue)
Creates an QueueCursor with the givenBlockingQueue
as its backing queue.
It may not be threadsafe to modify or access the givenBlockingQueue
from other locations. This method only enables the defaultArrayBlockingQueue
to be overridden.- Parameters:
queue
- A BlockingQueue that is not used in other locations, but will be used as the backing Queue implementation for this cursor.
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Method Detail
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convert
protected QueryEvaluationException convert(Exception e)
Description copied from class:QueueIteration
Converts an exception from the underlying iteration to an exception of type X.- Specified by:
convert
in classQueueIteration<E,QueryEvaluationException>
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