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;
21
22
23 import java.util.concurrent.atomic.AtomicInteger;
24
25 import org.apache.directory.api.ldap.model.schema.AttributeType;
26 import org.apache.directory.server.i18n.I18n;
27
28
29 /**
30 * A generic index implementation that is just used to hold the index configuration
31 * parameters (attributeId, cacheSize, wkDirPath). All other methods are not working.
32 *
33 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
34 */
35 public abstract class AbstractIndex<K, O, ID> implements Index<K, O, ID>
36 {
37 /** The attribute identifier for this index */
38 protected String attributeId;
39
40 /** the attribute type resolved for this JdbmIndex */
41 protected AttributeType attributeType;
42
43 /** the size (number of index entries) for the cache */
44 protected int cacheSize = DEFAULT_INDEX_CACHE_SIZE;
45
46 /** whether or not this index has been initialized */
47 protected boolean initialized;
48
49 /** Tells if this index has a Reverse table */
50 protected boolean withReverse;
51
52 /** A counter used to differ the commit on disk after N operations */
53 protected AtomicInteger commitNumber;
54
55
56 /**
57 * Creates a new instance of AbstractIndex.
58 *
59 * @param attributeId the attribute ID
60 */
61 protected AbstractIndex()
62 {
63 this( null, true );
64 }
65
66
67 /**
68 * Creates a new instance of AbstractIndex.
69 *
70 * @param attributeId the attribute ID
71 */
72 protected AbstractIndex( boolean withReverse )
73 {
74 this( null, withReverse );
75 }
76
77
78 /**
79 * Creates a new instance of AbstractIndex.
80 *
81 * @param attributeId the attribute ID
82 */
83 protected AbstractIndex( String attributeId, boolean withReverse )
84 {
85 this.attributeId = attributeId;
86 this.withReverse = withReverse;
87 commitNumber = new AtomicInteger( 0 );
88 }
89
90
91 public String getAttributeId()
92 {
93 return attributeId;
94 }
95
96
97 /**
98 * {@inheritDoc}
99 */
100 public AttributeType getAttribute()
101 {
102 return attributeType;
103 }
104
105
106 public void setAttributeId( String attributeId )
107 {
108 protect( "attributeId" );
109 this.attributeId = attributeId;
110 }
111
112
113 /**
114 * {@inheritDoc}
115 */
116 public boolean isDupsEnabled()
117 {
118 return !attributeType.isSingleValued();
119 }
120
121
122 /**
123 * Gets the size of the index cache in terms of the number of index entries to be cached.
124 *
125 * @return the size of the index cache
126 */
127 public int getCacheSize()
128 {
129 return cacheSize;
130 }
131
132
133 /**
134 * Sets the size of the index cache in terms of the number of index entries to be cached.
135 *
136 * @param cacheSize the size of the index cache
137 */
138 public void setCacheSize( int cacheSize )
139 {
140 protect( "cacheSize" );
141 this.cacheSize = cacheSize;
142 }
143
144
145 /**
146 * Protects configuration properties from being set after initialization.
147 *
148 * @param property the property to protect
149 */
150 protected void protect( String property )
151 {
152 if ( initialized )
153 {
154 throw new IllegalStateException( I18n.err( I18n.ERR_575, property ) );
155 }
156 }
157
158
159 /**
160 * {@inheritDoc}
161 */
162 public boolean hasReverse()
163 {
164 return withReverse;
165 }
166 }