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1   /*
2    *   Copyright 2004 The Apache Software Foundation
3    *
4    *   Licensed under the Apache License, Version 2.0 (the "License");
5    *   you may not use this file except in compliance with the License.
6    *   You may obtain a copy of the License at
7    *
8    *       http://www.apache.org/licenses/LICENSE-2.0
9    *
10   *   Unless required by applicable law or agreed to in writing, software
11   *   distributed under the License is distributed on an "AS IS" BASIS,
12   *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   *   See the License for the specific language governing permissions and
14   *   limitations under the License.
15   *
16   */
17  package org.apache.ldap.server.partition.impl.btree;
18  
19  
20  import javax.naming.NamingException;
21  
22  import org.apache.ldap.common.filter.ExprNode;
23  
24  
25  /***
26   * Tests if an entry is eligable for return by evaluating a filter expression on
27   * the candidate.  The evaluation can proceed by applying the filter on the 
28   * attributes of the entry itself or indices can be used for rapid evaluation.
29   * 
30   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
31   * @version $Rev: 264732 $
32   */
33  public interface Evaluator
34  {
35      /***
36       * Evaluates a candidate to determine if a filter expression selects it.
37       * 
38       * @param node the filter expression to evaluate on the candidate
39       * @param record the index record of the entry to evaluate
40       * @return true if the filter selects the candidate false otherwise
41       * @throws NamingException if there is a database fault during evaluation
42       */
43      boolean evaluate( ExprNode node, IndexRecord record ) throws NamingException;
44  }