Package org.eclipse.rdf4j.common.iteration

Class IntersectIteration<E>

java.lang.Object

org.eclipse.rdf4j.common.iteration.FilterIteration<E>

org.eclipse.rdf4j.common.iteration.IntersectIteration<E>

All Implemented Interfaces:

AutoCloseable, Iterator<E>, CloseableIteration<E>

public class IntersectIteration<E>
extends FilterIteration<E>

An Iteration that returns the intersection of the results of two Iterations. Optionally, the Iteration can be configured to filter duplicates from the returned elements.

Note that duplicates can also be filtered by wrapping this Iteration in a DistinctIteration, but that has a bit more overhead as it adds a second hash table lookup.

Field Summary

Fields

Modifier and Type	Field	Description
protected final CloseableIteration<? extends E>	arg2

Constructor Summary

Constructors

Constructor	Description
IntersectIteration(CloseableIteration<? extends E> arg1, CloseableIteration<? extends E> arg2)	Creates a new IntersectIteration that returns the intersection of the results of two Iterations.
IntersectIteration(CloseableIteration<? extends E> arg1, CloseableIteration<? extends E> arg2, boolean distinct)	Creates a new IntersectIteration that returns the intersection of the results of two Iterations.
IntersectIteration(CloseableIteration<? extends E> arg1, CloseableIteration<? extends E> arg2, boolean distinct, Supplier<Set<E>> setMaker)	Creates a new IntersectIteration that returns the intersection of the results of two Iterations.
IntersectIteration(CloseableIteration<? extends E> arg1, CloseableIteration<? extends E> arg2, Supplier<Set<E>> setMaker)

Method Summary

Modifier and Type	Method	Description
protected boolean	accept(E object)	Returns true if the object is in the set of elements of the second argument.
protected void	handleClose()	Closes this Iteration and also closes the wrapped Iteration if it is a CloseableIteration.
protected boolean	inIncludeSet(E object)
protected Set<E>	makeSet()
protected boolean	removeFromIncludeSet(E object)

Methods inherited from class org.eclipse.rdf4j.common.iteration.FilterIteration

close, hasNext, next, remove

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.CloseableIteration

stream

Methods inherited from interface java.util.Iterator

forEachRemaining

Field Details

arg2

protected final CloseableIteration<? extends E> arg2

Constructor Details

IntersectIteration

public IntersectIteration(CloseableIteration<? extends E> arg1,
 CloseableIteration<? extends E> arg2)

Creates a new IntersectIteration that returns the intersection of the results of two Iterations. By default, duplicates are not filtered from the results.

Parameters:

arg1 - An Iteration containing the first set of elements.

arg2 - An Iteration containing the second set of elements.

IntersectIteration

public IntersectIteration(CloseableIteration<? extends E> arg1,
 CloseableIteration<? extends E> arg2,
 Supplier<Set<E>> setMaker)

IntersectIteration

public IntersectIteration(CloseableIteration<? extends E> arg1,
 CloseableIteration<? extends E> arg2,
 boolean distinct)

Creates a new IntersectIteration that returns the intersection of the results of two Iterations.

Parameters:

arg1 - An Iteration containing the first set of elements.

arg2 - An Iteration containing the second set of elements.

distinct - Flag indicating whether duplicate elements should be filtered from the result.

IntersectIteration

public IntersectIteration(CloseableIteration<? extends E> arg1,
 CloseableIteration<? extends E> arg2,
 boolean distinct,
 Supplier<Set<E>> setMaker)

Creates a new IntersectIteration that returns the intersection of the results of two Iterations.

Parameters:

arg1 - An Iteration containing the first set of elements.

arg2 - An Iteration containing the second set of elements.

distinct - Flag indicating whether duplicate elements should be filtered from the result.

Method Details

accept

protected boolean accept(E object)

Returns true if the object is in the set of elements of the second argument.

Specified by:

accept in class FilterIteration<E>

Parameters:

object - The object to be tested.

Returns:

true if the object should be returned, false otherwise.

removeFromIncludeSet

protected boolean removeFromIncludeSet(E object)

inIncludeSet

protected boolean inIncludeSet(E object)

makeSet

protected Set<E> makeSet()

handleClose

protected void handleClose()

Description copied from class: FilterIteration

Closes this Iteration and also closes the wrapped Iteration if it is a CloseableIteration.

Specified by:

handleClose in class FilterIteration<E>