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.xdbm.search.impl;
21
22
23 import org.apache.directory.api.ldap.model.exception.LdapException;
24 import org.apache.directory.api.ldap.model.filter.BranchNode;
25 import org.apache.directory.api.ldap.model.filter.ExprNode;
26 import org.apache.directory.server.core.api.partition.PartitionTxn;
27 import org.apache.directory.server.xdbm.search.Optimizer;
28
29
30 /**
31 * A do nothing optimizer which labels all nodes with <code>
32 * BigInteger.valueOf( Integer.MAX_VALUE ) </code>, instead of actually
33 * taking scan counts.
34 *
35 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
36 */
37 public class NoOpOptimizer implements Optimizer
38 {
39 /** the maximum size for a count Integer.MAX_VALUE as a BigInteger */
40 private static final Long MAX = Long.MAX_VALUE;
41
42
43 public Long annotate( PartitionTxn partitionTxn, ExprNode node ) throws LdapException
44 {
45 if ( node.isLeaf() )
46 {
47 node.set( DefaultOptimizer.COUNT_ANNOTATION, MAX );
48 return MAX;
49 }
50
51 BranchNode bnode = ( BranchNode ) node;
52
53 if ( bnode.getChildren().isEmpty() )
54 {
55 bnode.set( DefaultOptimizer.COUNT_ANNOTATION, MAX );
56 return MAX;
57 }
58
59 final int limit = bnode.getChildren().size();
60 for ( int ii = 0; ii < limit; ii++ )
61 {
62 ExprNode child = bnode.getChildren().get( ii );
63 if ( child.isLeaf() )
64 {
65 child.set( DefaultOptimizer.COUNT_ANNOTATION, MAX );
66 }
67 else
68 {
69 annotate( partitionTxn, child );
70 }
71 }
72
73 bnode.set( DefaultOptimizer.COUNT_ANNOTATION, MAX );
74 return MAX;
75 }
76 }