/*
|
* CDDL HEADER START
|
*
|
* The contents of this file are subject to the terms of the
|
* Common Development and Distribution License, Version 1.0 only
|
* (the "License"). You may not use this file except in compliance
|
* with the License.
|
*
|
* You can obtain a copy of the license at
|
* trunk/opends/resource/legal-notices/OpenDS.LICENSE
|
* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
|
* See the License for the specific language governing permissions
|
* and limitations under the License.
|
*
|
* When distributing Covered Code, include this CDDL HEADER in each
|
* file and include the License file at
|
* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
|
* add the following below this CDDL HEADER, with the fields enclosed
|
* by brackets "[]" replaced with your own identifying information:
|
* Portions Copyright [yyyy] [name of copyright owner]
|
*
|
* CDDL HEADER END
|
*
|
*
|
* Copyright 2009 Sun Microsystems, Inc.
|
*/
|
|
|
package org.opends.server.backends.jeb;
|
|
import java.util.Collection;
|
import static org.opends.server.backends.jeb.IndexFilter.*;
|
|
|
/**
|
* This class represents a JE Backend Query.
|
*/
|
@org.opends.server.types.PublicAPI(
|
stability=org.opends.server.types.StabilityLevel.VOLATILE,
|
mayInstantiate=false,
|
mayExtend=true,
|
mayInvoke=false)
|
public abstract class IndexQuery
|
{
|
/**
|
* Evaluates the index query and returns the EntryIDSet.
|
* @return The EntryIDSet as a result of evaulation of this query.
|
*/
|
public abstract EntryIDSet evaluate();
|
|
|
|
/**
|
* Creates an IntersectionIndexQuery object from a collection of IndexQuery
|
* objects.
|
* @param subIndexQueries A collection of IndexQuery objects.
|
* @return An IntersectionIndexQuery object.
|
*/
|
public static IndexQuery createIntersectionIndexQuery(
|
Collection<IndexQuery> subIndexQueries)
|
{
|
return new IntersectionIndexQuery(subIndexQueries);
|
}
|
|
|
|
/**
|
* Creates a union IndexQuery object from a collection of IndexQuery
|
* objects.
|
* @param subIndexQueries Collection of IndexQuery objects.
|
* @return A UnionIndexQuery object.
|
*/
|
public static IndexQuery createUnionIndexQuery(
|
Collection<IndexQuery> subIndexQueries)
|
{
|
return new UnionIndexQuery(subIndexQueries);
|
}
|
|
|
|
/**
|
* Creates an empty IndexQuery object.
|
* @return A NullIndexQuery object.
|
*/
|
public static IndexQuery createNullIndexQuery()
|
{
|
return new NullIndexQuery();
|
}
|
}
|
|
|
|
/**
|
* This class creates a Null IndexQuery. It is used when there
|
* is no record in the index. It may also be used when the
|
* index contains all the records but an empty EntryIDSet should be
|
* returned as part of the optimization.
|
*/
|
final class NullIndexQuery extends IndexQuery
|
{
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public EntryIDSet evaluate()
|
{
|
return new EntryIDSet();
|
}
|
}
|
|
|
|
|
|
/**
|
* This class creates an intersection IndexQuery from a collection of
|
* IndexQuery objects.
|
*/
|
final class IntersectionIndexQuery extends IndexQuery
|
{
|
/**
|
* Collection of IndexQuery objects.
|
*/
|
private final Collection<IndexQuery> subIndexQueries;
|
|
|
/**
|
* Creates an instance of IntersectionIndexQuery.
|
* @param subIndexQueries Collection of IndexQuery objects.
|
*/
|
IntersectionIndexQuery(Collection<IndexQuery> subIndexQueries)
|
{
|
this.subIndexQueries = subIndexQueries;
|
}
|
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public EntryIDSet evaluate()
|
{
|
EntryIDSet entryIDs = null;
|
for (IndexQuery query : subIndexQueries)
|
{
|
if (entryIDs == null)
|
{
|
entryIDs = query.evaluate();
|
}
|
else
|
{
|
entryIDs.retainAll(query.evaluate());
|
}
|
if (entryIDs.isDefined() &&
|
entryIDs.size() <= FILTER_CANDIDATE_THRESHOLD)
|
{
|
break;
|
}
|
}
|
return entryIDs;
|
}
|
}
|
|
/**
|
* This class creates a union of IndexQuery objects.
|
*/
|
final class UnionIndexQuery extends IndexQuery
|
{
|
/**
|
* Collection containing IndexQuery objects.
|
*/
|
private final Collection<IndexQuery> subIndexQueries;
|
|
/**
|
* Creates an instance of UnionIndexQuery.
|
* @param subIndexQueries The Collection of IndexQuery objects.
|
*/
|
UnionIndexQuery(Collection<IndexQuery> subIndexQueries)
|
{
|
this.subIndexQueries = subIndexQueries;
|
}
|
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public EntryIDSet evaluate()
|
{
|
EntryIDSet entryIDs = null;
|
for (IndexQuery query : subIndexQueries)
|
{
|
if (entryIDs == null)
|
{
|
entryIDs = query.evaluate();
|
}
|
else
|
{
|
entryIDs.addAll(query.evaluate());
|
}
|
if (entryIDs.isDefined() &&
|
entryIDs.size() <= FILTER_CANDIDATE_THRESHOLD)
|
{
|
break;
|
}
|
}
|
return entryIDs;
|
}
|
}
|
