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.evaluator;
21
22
23 import org.apache.directory.api.ldap.model.entry.Entry;
24 import org.apache.directory.api.ldap.model.exception.LdapException;
25 import org.apache.directory.api.ldap.model.filter.ScopeNode;
26 import org.apache.directory.server.core.api.partition.PartitionTxn;
27 import org.apache.directory.server.i18n.I18n;
28 import org.apache.directory.server.xdbm.IndexEntry;
29 import org.apache.directory.server.xdbm.Store;
30 import org.apache.directory.server.xdbm.search.Evaluator;
31
32
33 /**
34 * Evaluates base level scope assertions on candidates using an entry database.
35 *
36 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
37 */
38 public class BaseLevelScopeEvaluator<E> implements Evaluator<ScopeNode>
39 {
40 /** The ScopeNode containing initial search scope constraints */
41 private final ScopeNode node;
42
43 /** The entry identifier of the scope base */
44 private final String baseId;
45
46 /** True if the scope requires alias dereferencing while searching */
47 private final boolean dereferencing;
48
49 /** the entry db storing entries */
50 private final Store db;
51
52
53 /**
54 * Creates a one level scope node Evaluator for search expressions.
55 *
56 * @param db the database used to evaluate scope node
57 * @param node the scope node
58 */
59 public BaseLevelScopeEvaluator( Store db, ScopeNode node )
60 {
61 this.node = node;
62
63 this.db = db;
64 baseId = node.getBaseId();
65 dereferencing = node.getDerefAliases().isDerefInSearching() || node.getDerefAliases().isDerefAlways();
66 }
67
68
69 /**
70 * Asserts whether or not a candidate has one level scope while taking
71 * alias dereferencing into account.
72 *
73 * TODO - terribly inefficient - would benefit from exposing the id of an
74 * entry within the Entry
75 *
76 * {@inheritDoc}
77 */
78 public boolean evaluate( Entry candidate ) throws LdapException
79 {
80 throw new UnsupportedOperationException( I18n.err( I18n.ERR_721 ) );
81 }
82
83
84 /**
85 * {@inheritDoc}
86 */
87 @Override
88 public boolean evaluate( PartitionTxn partitionTxn, IndexEntry<?, String> indexEntry ) throws LdapException
89 {
90 Entry entry = indexEntry.getEntry();
91
92 // Fetch the entry
93 if ( null == entry )
94 {
95 entry = db.fetch( partitionTxn, indexEntry.getId() );
96
97 if ( null == entry )
98 {
99 // The entry is not anymore present : get out
100 return false;
101 }
102
103 indexEntry.setEntry( entry );
104 }
105
106 return true;
107 }
108
109
110 public ScopeNode getExpression()
111 {
112 return node;
113 }
114
115
116 /**
117 * Gets the id of the search base associated with the ScopeNode expression.
118 *
119 * @return identifier of the search base
120 */
121 public String getBaseId()
122 {
123 return baseId;
124 }
125
126
127 /**
128 * Gets whether or not dereferencing is enabled for this evaluator.
129 *
130 * @return true if dereferencing is enabled, false otherwise
131 */
132 public boolean isDereferencing()
133 {
134 return dereferencing;
135 }
136
137
138 /**
139 * @see Object#toString()
140 */
141 public String toString( String tabs )
142 {
143 StringBuilder sb = new StringBuilder();
144
145 sb.append( tabs ).append( "BaseLevelScopEvaluator : " ).append( node ).append( "\n" );
146
147 return sb.toString();
148 }
149
150
151 /**
152 * @see Object#toString()
153 */
154 public String toString()
155 {
156 return toString( "" );
157 }
158 }