/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package hivemall.mix.store;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import javax.annotation.Nonnegative;
import javax.annotation.Nonnull;
import javax.annotation.concurrent.ThreadSafe;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
@ThreadSafe
public final class SessionStore {
private static final int EXPECTED_MODEL_SIZE = 4194305; /* 2^22+1=4194304+1=4194305 */
private static final Log logger = LogFactory.getLog(SessionStore.class);
private final ConcurrentMap<String, SessionObject> sessions;
public SessionStore() {
this.sessions = new ConcurrentHashMap<String, SessionObject>();
}
@Nonnull
private ConcurrentMap<String, SessionObject> getSessions() {
return sessions;
}
@Nonnull
public SessionObject get(@Nonnull String groupID) {
SessionObject sessionObj = sessions.get(groupID);
if (sessionObj == null) {
ConcurrentMap<Object, PartialResult> map = new ConcurrentHashMap<Object, PartialResult>(
EXPECTED_MODEL_SIZE);
sessionObj = new SessionObject(map);
SessionObject existing = sessions.putIfAbsent(groupID, sessionObj);
if (existing != null) {
sessionObj = existing;
}
}
return sessionObj;
}
public void remove(@Nonnull String groupID) {
SessionObject removedSession = sessions.remove(groupID);
if (removedSession != null) {
logger.info("Removed an idle session group: " + groupID + "\t"
+ removedSession.getSessionInfo());
}
}
@ThreadSafe
public static final class IdleSessionSweeper implements Runnable {
private final ConcurrentMap<String, SessionObject> sessions;
private final long ttl;
public IdleSessionSweeper(@Nonnull SessionStore sessionStore, @Nonnegative long ttlInMillis) {
this.sessions = sessionStore.getSessions();
this.ttl = ttlInMillis;
}
public void run() {
final Set<Map.Entry<String, SessionObject>> entries = sessions.entrySet();
final Iterator<Map.Entry<String, SessionObject>> itor = entries.iterator();
while (itor.hasNext()) {
Map.Entry<String, SessionObject> e = itor.next();
SessionObject sessionObj = e.getValue();
long lastAccessed = sessionObj.getLastAccessed();
long elapsedTime = System.currentTimeMillis() - lastAccessed;
if (elapsedTime > ttl) {
itor.remove();
if (logger.isInfoEnabled()) {
logger.info("Removed an idle session group: " + e.getKey() + "\t"
+ sessionObj.getSessionInfo());
}
}
}
}
}
}