001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one
003     *  or more contributor license agreements.  See the NOTICE file
004     *  distributed with this work for additional information
005     *  regarding copyright ownership.  The ASF licenses this file
006     *  to you under the Apache License, Version 2.0 (the
007     *  "License"); you may not use this file except in compliance
008     *  with the License.  You may obtain a copy of the License at
009     *  
010     *    http://www.apache.org/licenses/LICENSE-2.0
011     *  
012     *  Unless required by applicable law or agreed to in writing,
013     *  software distributed under the License is distributed on an
014     *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     *  KIND, either express or implied.  See the License for the
016     *  specific language governing permissions and limitations
017     *  under the License. 
018     *  
019     */
020    package org.apache.directory.server.xdbm.search.impl;
021    
022    
023    import org.apache.directory.shared.ldap.entry.ServerEntry;
024    import org.apache.directory.shared.ldap.filter.NotNode;
025    import org.apache.directory.shared.ldap.filter.ExprNode;
026    import org.apache.directory.server.xdbm.IndexEntry;
027    import org.apache.directory.server.xdbm.search.Evaluator;
028    
029    
030    /**
031     * An Evaluator for logical negation (NOT) expressions.
032     *
033     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
034     * @version $$Rev$$
035     */
036    public class NotEvaluator<ID> implements Evaluator<NotNode, ServerEntry, ID>
037    {
038        private final NotNode node;
039        private final Evaluator<? extends ExprNode, ServerEntry, ID> childEvaluator;
040    
041    
042        public NotEvaluator( NotNode node, Evaluator<? extends ExprNode, ServerEntry, ID> childEvaluator )
043        {
044            this.node = node;
045            this.childEvaluator = childEvaluator;
046        }
047    
048    
049        public boolean evaluateId( ID id ) throws Exception
050        {
051            return !childEvaluator.evaluateId( id );
052        }
053    
054    
055        public boolean evaluateEntry( ServerEntry entry ) throws Exception
056        {
057            return !childEvaluator.evaluateEntry( entry );
058        }
059    
060    
061        public boolean evaluate( IndexEntry<?, ServerEntry, ID> indexEntry ) throws Exception
062        {
063            return !childEvaluator.evaluate( indexEntry );
064        }
065    
066    
067        public NotNode getExpression()
068        {
069            return node;
070        }
071    }