org.eclipse.rdf4j.federated.evaluation.iterator

Class LazyMutableClosableIteration

java.lang.Object

org.eclipse.rdf4j.federated.evaluation.iterator.LazyMutableClosableIteration

All Implemented Interfaces:

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

public class LazyMutableClosableIteration
extends Object
implements CloseableIteration<BindingSet,QueryEvaluationException>

A specialized CloseableIteration that allows repetitive iterations after resetting the cursor using resetCursor().

Note that the inner iteration is lazily consumed.

Author:

Andreas Schwarte

Field Summary

Fields

Modifier and Type	Field and Description
protected List<BindingSet>	consumed
protected int	cursorIdx the cursor index, is used after the inner iteration is fully consumed
protected CloseableIteration<BindingSet,QueryEvaluationException>	inner

Constructor Summary

Constructors

Constructor and Description
LazyMutableClosableIteration(CloseableIteration<BindingSet,QueryEvaluationException> inner)

Method Summary

Modifier and Type	Method and Description
void	close() Closes this iteration, freeing any resources that it is holding.
boolean	hasNext() Returns true if the iteration has more elements.
BindingSet	next() Returns the next element in the iteration.
void	remove() Removes from the underlying collection the last element returned by the iteration (optional operation).
void	resetCursor() Reset the cursor to read from the already consumed bindings.

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

Field Detail

inner

protected final CloseableIteration<BindingSet,QueryEvaluationException> inner

consumed

protected List<BindingSet> consumed

cursorIdx

protected volatile int cursorIdx

the cursor index, is used after the inner iteration is fully consumed

Constructor Detail

LazyMutableClosableIteration

public LazyMutableClosableIteration(CloseableIteration<BindingSet,QueryEvaluationException> inner)

Method Detail

hasNext

public boolean hasNext()
                throws QueryEvaluationException

Description copied from interface: Iteration

Returns true if the iteration has more elements. (In other words, returns true if Iteration.next() would return an element rather than throwing a NoSuchElementException.)

Specified by:

hasNext in interface Iteration<BindingSet,QueryEvaluationException>

Returns:

true if the iteration has more elements.

Throws:

QueryEvaluationException

next

public BindingSet next()
                throws QueryEvaluationException

Description copied from interface: Iteration

Returns the next element in the iteration.

Specified by:

next in interface Iteration<BindingSet,QueryEvaluationException>

Returns:

the next element in the iteration.

Throws:

QueryEvaluationException

remove

public void remove()
            throws QueryEvaluationException

Description copied from interface: Iteration

Removes from the underlying collection the last element returned by the iteration (optional operation). This method can be called only once per call to next.

Specified by:

remove in interface Iteration<BindingSet,QueryEvaluationException>

Throws:

QueryEvaluationException

close

public void close()
           throws QueryEvaluationException

Description copied from interface: CloseableIteration

Closes this iteration, freeing any resources that it is holding. If the iteration has already been closed then invoking this method has no effect.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface CloseableIteration<BindingSet,QueryEvaluationException>

Throws:

QueryEvaluationException

resetCursor

public void resetCursor()

Reset the cursor to read from the already consumed bindings.