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.i18n.I18n;
27 import org.apache.directory.server.xdbm.IndexEntry;
28 import org.apache.directory.server.xdbm.Store;
29 import org.apache.directory.server.xdbm.search.Evaluator;
30
31
32 /**
33 * Evaluates base level scope assertions on candidates using an entry database.
34 *
35 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
36 */
37 public class BaseLevelScopeEvaluator<E> implements Evaluator<ScopeNode>
38 {
39 /** The ScopeNode containing initial search scope constraints */
40 private final ScopeNode node;
41
42 /** The entry identifier of the scope base */
43 private final String baseId;
44
45 /** True if the scope requires alias dereferencing while searching */
46 private final boolean dereferencing;
47
48 /** the entry db storing entries */
49 private final Store db;
50
51
52 /**
53 * Creates a one level scope node Evaluator for search expressions.
54 *
55 * @param node the scope node
56 * @param db the database used to evaluate scope node
57 * @throws Exception on db access failure
58 */
59 public BaseLevelScopeEvaluator( Store db, ScopeNode node ) throws Exception
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 Exception
79 {
80 throw new UnsupportedOperationException( I18n.err( I18n.ERR_721 ) );
81 }
82
83
84 /**
85 * Asserts whether or not a candidate has one level scope while taking
86 * alias dereferencing into account.
87 *
88 * @param candidate the candidate to assert
89 * @return true if the candidate is within one level scope
90 * @throws Exception if db lookups fail
91 * @see org.apache.directory.server.xdbm.search.Evaluator#evaluate(IndexEntry)
92 */
93 public boolean evaluate( IndexEntry<?, String> indexEntry ) throws LdapException
94 {
95 Entry entry = indexEntry.getEntry();
96
97 // Fetch the entry
98 if ( null == entry )
99 {
100 entry = db.fetch( indexEntry.getId() );
101
102 if ( null == entry )
103 {
104 // The entry is not anymore present : get out
105 return false;
106 }
107
108 indexEntry.setEntry( entry );
109 }
110
111 return true;
112 }
113
114
115 public ScopeNode getExpression()
116 {
117 return node;
118 }
119
120
121 /**
122 * Gets the id of the search base associated with the ScopeNode expression.
123 *
124 * @return identifier of the search base
125 */
126 public String getBaseId()
127 {
128 return baseId;
129 }
130
131
132 /**
133 * Gets whether or not dereferencing is enabled for this evaluator.
134 *
135 * @return true if dereferencing is enabled, false otherwise
136 */
137 public boolean isDereferencing()
138 {
139 return dereferencing;
140 }
141
142
143 /**
144 * @see Object#toString()
145 */
146 public String toString( String tabs )
147 {
148 StringBuilder sb = new StringBuilder();
149
150 sb.append( tabs ).append( "BaseLevelScopEvaluator : " ).append( node ).append( "\n" );
151
152 return sb.toString();
153 }
154
155
156 /**
157 * @see Object#toString()
158 */
159 public String toString()
160 {
161 return toString( "" );
162 }
163 }