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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *  
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *  
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License. 
18   *  
19   */
20  package org.apache.directory.server.core.event;
21  
22  
23  import javax.naming.NamingException;
24  
25  import org.apache.directory.server.core.entry.ServerEntry;
26  import org.apache.directory.shared.ldap.filter.ExprNode;
27  
28  
29  /**
30   * Tests if an entry is eligible for return by evaluating a filter expression on
31   * the candidate.  The evaluation can proceed by applying the filter on the 
32   * attributes of the entry itself or indices can be used for rapid evaluation.
33   * 
34   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
35   * @version $Rev: 666516 $
36   */
37  public interface Evaluator
38  {
39      /**
40       * Evaluates a candidate to determine if a filter expression selects it.
41       * 
42       * @param node the filter expression to evaluate on the candidate
43       * @param dn the normalized distinguished name of the entry being tested
44       * @param entry the entry to evaluate
45       * @return true if the filter selects the candidate false otherwise
46       * @throws javax.naming.NamingException if there is a database fault during evaluation
47       */
48      boolean evaluate( ExprNode node, String dn, ServerEntry entry ) throws NamingException;
49  }