Class BindLeftJoinIteration
- java.lang.Object
-
- org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E>
-
- org.eclipse.rdf4j.common.iteration.LookAheadIteration<BindingSet>
-
- org.eclipse.rdf4j.federated.evaluation.iterator.BindLeftJoinIteration
-
- All Implemented Interfaces:
AutoCloseable
,Iterator<BindingSet>
,CloseableIteration<BindingSet>
public class BindLeftJoinIteration extends LookAheadIteration<BindingSet>
ALookAheadIteration
for processing bind left join results (i.e., result of joining OPTIONAL clauses) Algorithm:- execute left bind join using regular bound join query
- process result iteration similar to
BoundJoinVALUESConversionIteration
- remember seen set of bindings (using index) and add original bindings to those, i.e. put to result return all non-seen bindings directly from the input
- Author:
- Andreas Schwarte
-
-
Field Summary
Fields Modifier and Type Field Description protected List<BindingSet>
bindings
protected ListIterator<BindingSet>
bindingsIterator
protected CloseableIteration<BindingSet>
iter
protected org.eclipse.collections.impl.set.mutable.primitive.IntHashSet
seenBindingIndexes
-
Constructor Summary
Constructors Constructor Description BindLeftJoinIteration(CloseableIteration<BindingSet> iter, List<BindingSet> bindings)
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected BindingSet
convert(BindingSet bIn, int bIndex)
protected BindingSet
getNextElement()
Gets the next element.protected void
handleClose()
Called byAbstractCloseableIteration.close()
when it is called for the first time.-
Methods inherited from class org.eclipse.rdf4j.common.iteration.LookAheadIteration
hasNext, next, remove
-
Methods inherited from class org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration
close, isClosed
-
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 Detail
-
iter
protected final CloseableIteration<BindingSet> iter
-
bindings
protected final List<BindingSet> bindings
-
seenBindingIndexes
protected org.eclipse.collections.impl.set.mutable.primitive.IntHashSet seenBindingIndexes
-
bindingsIterator
protected final ListIterator<BindingSet> bindingsIterator
-
-
Constructor Detail
-
BindLeftJoinIteration
public BindLeftJoinIteration(CloseableIteration<BindingSet> iter, List<BindingSet> bindings)
-
-
Method Detail
-
getNextElement
protected BindingSet getNextElement()
Description copied from class:LookAheadIteration
Gets the next element. Subclasses should implement this method so that it returns the next element.- Specified by:
getNextElement
in classLookAheadIteration<BindingSet>
- Returns:
- The next element, or null if no more elements are available.
-
handleClose
protected void handleClose()
Description copied from class:AbstractCloseableIteration
Called byAbstractCloseableIteration.close()
when it is called for the first time. This method is only called once on each iteration. By default, this method does nothing.- Specified by:
handleClose
in classAbstractCloseableIteration<BindingSet>
-
convert
protected BindingSet convert(BindingSet bIn, int bIndex) throws QueryEvaluationException
- Throws:
QueryEvaluationException
-
-