org.modeshape.jcr.query.process
Class SetOperationComponent

java.lang.Object
  org.modeshape.jcr.query.process.ProcessingComponent
      org.modeshape.jcr.query.process.SetOperationComponent

Direct Known Subclasses:

ExceptComponent, IntersectComponent, UnionComponent

public abstract class SetOperationComponent
extends ProcessingComponent

Nested Class Summary

Nested classes/interfaces inherited from class org.modeshape.jcr.query.process.ProcessingComponent

ProcessingComponent.DynamicOperation

Field Summary

protected Comparator<Object[]>

removeDuplicatesComparator

Constructor Summary

protected

SetOperationComponent(QueryContext context, QueryResults.Columns columns, Iterable<ProcessingComponent> sources, boolean alreadySorted, boolean all)

Method Summary

protected void	removeDuplicatesIfRequested(List<Object[]> tuples)
protected Iterable<ProcessingComponent>	sources()
protected static boolean	unionCompatible(QueryResults.Columns columns, Iterable<ProcessingComponent> sources)
protected static Iterable<ProcessingComponent>	wrapWithLocationOrdering(Iterable<ProcessingComponent> sources, boolean alreadySorted) The sources' results must be sorted before the intersection can be computed.

Methods inherited from class org.modeshape.jcr.query.process.ProcessingComponent

close, createDynamicOperation, createSortComparator, emptyTuples, execute, getColumns, getContext, problems

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

removeDuplicatesComparator

protected final Comparator<Object[]> removeDuplicatesComparator

Constructor Detail

SetOperationComponent

protected SetOperationComponent(QueryContext context,
                                QueryResults.Columns columns,
                                Iterable<ProcessingComponent> sources,
                                boolean alreadySorted,
                                boolean all)

Method Detail

unionCompatible

protected static boolean unionCompatible(QueryResults.Columns columns,
                                         Iterable<ProcessingComponent> sources)

sources

protected Iterable<ProcessingComponent> sources()

Returns:

sources

wrapWithLocationOrdering

protected static Iterable<ProcessingComponent> wrapWithLocationOrdering(Iterable<ProcessingComponent> sources,
                                                                        boolean alreadySorted)

The sources' results must be sorted before the intersection can be computed. Ensure that the sources' results are indeed sorted, and if not wrap them in a sorting component.

Parameters:

sources - the sources being intersected; may not be null

alreadySorted - true if the sources' results are already sorted, or false if they must be sorted by this component

Returns:

the sources (or their wrappers); never null

removeDuplicatesIfRequested

protected void removeDuplicatesIfRequested(List<Object[]> tuples)