/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
package org.apache.directory.server.xdbm.search.impl;
import java.util.ArrayList;
import java.util.List;
import org.apache.directory.server.i18n.I18n;
import org.apache.directory.server.xdbm.Store;
import org.apache.directory.server.xdbm.search.Evaluator;
import org.apache.directory.server.xdbm.search.evaluator.AndEvaluator;
import org.apache.directory.server.xdbm.search.evaluator.ApproximateEvaluator;
import org.apache.directory.server.xdbm.search.evaluator.EqualityEvaluator;
import org.apache.directory.server.xdbm.search.evaluator.GreaterEqEvaluator;
import org.apache.directory.server.xdbm.search.evaluator.LessEqEvaluator;
import org.apache.directory.server.xdbm.search.evaluator.NotEvaluator;
import org.apache.directory.server.xdbm.search.evaluator.OneLevelScopeEvaluator;
import org.apache.directory.server.xdbm.search.evaluator.OrEvaluator;
import org.apache.directory.server.xdbm.search.evaluator.PresenceEvaluator;
import org.apache.directory.server.xdbm.search.evaluator.SubstringEvaluator;
import org.apache.directory.server.xdbm.search.evaluator.SubtreeScopeEvaluator;
import org.apache.directory.shared.ldap.model.entry.Entry;
import org.apache.directory.shared.ldap.model.filter.AndNode;
import org.apache.directory.shared.ldap.model.filter.ApproximateNode;
import org.apache.directory.shared.ldap.model.filter.EqualityNode;
import org.apache.directory.shared.ldap.model.filter.ExprNode;
import org.apache.directory.shared.ldap.model.filter.GreaterEqNode;
import org.apache.directory.shared.ldap.model.filter.LessEqNode;
import org.apache.directory.shared.ldap.model.filter.NotNode;
import org.apache.directory.shared.ldap.model.filter.OrNode;
import org.apache.directory.shared.ldap.model.filter.PresenceNode;
import org.apache.directory.shared.ldap.model.filter.ScopeNode;
import org.apache.directory.shared.ldap.model.filter.SubstringNode;
import org.apache.directory.shared.ldap.model.message.SearchScope;
import org.apache.directory.shared.ldap.model.schema.SchemaManager;
import org.apache.directory.shared.util.exception.NotImplementedException;
/**
* Top level filter expression evaluator builder implemenation.
*
* @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
*/
public class EvaluatorBuilder
{
private final Store db;
private final SchemaManager schemaManager;
/**
* Creates a top level Evaluator where leaves are delegated to a leaf node
* evaluator which will be created.
*
* @param db the database this evaluator operates upon
* @param schemaManager the schema manager
* @throws Exception failure to access db or lookup schema in registries
*/
public EvaluatorBuilder( Store db, SchemaManager schemaManager ) throws Exception
{
this.db = db;
this.schemaManager = schemaManager;
}
public <T> Evaluator<? extends ExprNode> build( ExprNode node ) throws Exception
{
Object count = node.get( "count" );
if ( ( count != null ) && ( ( Long ) count == 0L ) )
{
return null;
}
switch ( node.getAssertionType() )
{
/* ---------- LEAF NODE HANDLING ---------- */
case APPROXIMATE:
return new ApproximateEvaluator<T>( ( ApproximateNode<T> ) node, db, schemaManager );
case EQUALITY:
return new EqualityEvaluator<T>( ( EqualityNode<T> ) node, db, schemaManager );
case GREATEREQ:
return new GreaterEqEvaluator<T>( ( GreaterEqNode<T> ) node, db, schemaManager );
case LESSEQ:
return new LessEqEvaluator<T>( ( LessEqNode<T> ) node, db, schemaManager );
case PRESENCE:
return new PresenceEvaluator( ( PresenceNode ) node, db, schemaManager );
case SCOPE:
if ( ( ( ScopeNode ) node ).getScope() == SearchScope.ONELEVEL )
{
return new OneLevelScopeEvaluator<Entry>( db, ( ScopeNode ) node );
}
else
{
return new SubtreeScopeEvaluator( db, ( ScopeNode ) node );
}
case SUBSTRING:
return new SubstringEvaluator( ( SubstringNode ) node, db, schemaManager );
/* ---------- LOGICAL OPERATORS ---------- */
case AND:
return buildAndEvaluator( ( AndNode ) node );
case NOT:
return new NotEvaluator( ( NotNode ) node, build( ( ( NotNode ) node ).getFirstChild() ) );
case OR:
return buildOrEvaluator( ( OrNode ) node );
/* ---------- NOT IMPLEMENTED ---------- */
case ASSERTION:
case EXTENSIBLE:
throw new NotImplementedException();
default:
throw new IllegalStateException( I18n.err( I18n.ERR_260, node.getAssertionType() ) );
}
}
private <T> Evaluator<? extends ExprNode> buildAndEvaluator( AndNode node ) throws Exception
{
List<ExprNode> children = node.getChildren();
List<Evaluator<? extends ExprNode>> evaluators = buildList( children );
int size = evaluators.size();
switch ( size )
{
case 0:
return null;
case 1:
return evaluators.get( 0 );
default:
return new AndEvaluator( node, evaluators );
}
}
private <T> Evaluator<? extends ExprNode> buildOrEvaluator( OrNode node ) throws Exception
{
List<ExprNode> children = node.getChildren();
List<Evaluator<? extends ExprNode>> evaluators = buildList( children );
int size = evaluators.size();
switch ( size )
{
case 0:
return null;
case 1:
return evaluators.get( 0 );
default:
return new OrEvaluator( node, evaluators );
}
}
private List<Evaluator<? extends ExprNode>> buildList( List<ExprNode> children ) throws Exception
{
List<Evaluator<? extends ExprNode>> evaluators = new ArrayList<Evaluator<? extends ExprNode>>(
children.size() );
for ( ExprNode child : children )
{
Evaluator<? extends ExprNode> evaluator = build( child );
if ( evaluator != null )
{
evaluators.add( evaluator );
}
}
return evaluators;
}
}