001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied. See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 *
019 */
020 package org.apache.directory.server.ldap.handlers;
021
022
023 import java.util.concurrent.TimeUnit;
024
025 import org.apache.directory.shared.ldap.cursor.ClosureMonitor;
026 import org.apache.directory.shared.ldap.cursor.CursorClosedException;
027 import org.apache.directory.shared.ldap.exception.LdapTimeLimitExceededException;
028
029
030 /**
031 * A ClosureMonitor implementation which takes into account a time limit.
032 *
033 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
034 * @version $Rev$, $Date$
035 */
036 public class SearchTimeLimitingMonitor implements ClosureMonitor
037 {
038 private final long startTime = System.currentTimeMillis();
039 private final long millisToLive;
040
041 private boolean closed;
042 private Exception cause;
043
044
045 /**
046 * Creates a new instance of SearchTimeLimitingMonitor.
047 *
048 * @param timeToLive the time before changing state to closed.
049 * @param unit the time units for the timeToLive parameter
050 * @see {@link TimeUnit}
051 */
052 public SearchTimeLimitingMonitor( long timeToLive, TimeUnit unit )
053 {
054 switch ( unit )
055 {
056 case MICROSECONDS:
057 this.millisToLive = timeToLive / 1000;
058 break;
059 case MILLISECONDS:
060 this.millisToLive = timeToLive;
061 break;
062 case SECONDS:
063 this.millisToLive = timeToLive * 1000;
064 break;
065 default:
066 throw new IllegalStateException( "TimeUnit not supported: " + unit );
067 }
068 }
069
070
071 /*
072 * (non-Javadoc)
073 * @see org.apache.directory.server.core.cursor.ClosureMonitor#checkNotClosed()
074 */
075 public void checkNotClosed() throws Exception
076 {
077 if ( System.currentTimeMillis() > startTime + millisToLive )
078 {
079 // state check needed to "try" not to overwrite exception (lack of
080 // synchronization may still allow overwriting but who cares that
081 // much
082 if ( ! closed )
083 {
084 // not going to sync because who cares if it takes a little
085 // longer to stop but we need to set cause before toggling
086 // closed state or else check for closure can throw null cause
087 cause = new LdapTimeLimitExceededException();
088 closed = true;
089 }
090 }
091
092 if ( closed )
093 {
094 throw cause;
095 }
096 }
097
098
099 /*
100 * (non-Javadoc)
101 * @see org.apache.directory.server.core.cursor.ClosureMonitor#close()
102 */
103 public void close()
104 {
105 if ( ! closed )
106 {
107 // not going to sync because who cares if it takes a little longer
108 // to stop but we need to set cause before toggling closed state
109 // or else check for closure can throw null cause
110 cause = new CursorClosedException();
111 closed = true;
112 }
113 }
114
115
116 /*
117 * (non-Javadoc)
118 * @see org.apache.directory.server.core.cursor.ClosureMonitor#close(java.lang.String)
119 */
120 public void close( String cause )
121 {
122 if ( ! closed )
123 {
124 // not going to sync because who cares if it takes a little longer
125 // to stop but we need to set cause before toggling closed state
126 // or else check for closure can throw null cause
127 this.cause = new CursorClosedException( cause );
128 closed = true;
129 }
130 }
131
132
133 /*
134 * (non-Javadoc)
135 * @see org.apache.directory.server.core.cursor.ClosureMonitor#close(java.lang.Exception)
136 */
137 public void close( Exception cause )
138 {
139 if ( ! closed )
140 {
141 // not going to sync because who cares if it takes a little longer
142 // to stop but we need to set cause before toggling closed state
143 // or else check for closure can throw null cause
144 this.cause = cause;
145 closed = true;
146 }
147 }
148
149
150 /*
151 * (non-Javadoc)
152 * @see org.apache.directory.server.core.cursor.ClosureMonitor#getCause()
153 */
154 public Exception getCause()
155 {
156 return cause;
157 }
158
159
160 /*
161 * (non-Javadoc)
162 * @see org.apache.directory.server.core.cursor.ClosureMonitor#isClosed()
163 */
164 public boolean isClosed()
165 {
166 if ( System.currentTimeMillis() > startTime + millisToLive )
167 {
168 // set cause first always
169 cause = new LdapTimeLimitExceededException();
170 closed = true;
171 }
172
173 return closed;
174 }
175 }
176
177