/*
* 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 org.apache.wicket.protocol.ws.api.registry;
import java.util.ArrayList;
import java.util.Collection;
import java.util.concurrent.ConcurrentMap;
import org.apache.wicket.Application;
import org.apache.wicket.MetaDataKey;
import org.apache.wicket.protocol.ws.api.IWebSocketConnection;
import org.apache.wicket.util.lang.Args;
import org.apache.wicket.util.lang.Generics;
/**
* A registry that keeps all currently opened web socket connections in
* maps in Application's meta data.
*
* TODO remove the synchronizations below and use ConcurrentMap#putIfAbsent()
*
* @since 6.0
*/
public class SimpleWebSocketConnectionRegistry implements IWebSocketConnectionRegistry
{
private static final MetaDataKey<ConcurrentMap<String, ConcurrentMap<IKey, IWebSocketConnection>>> KEY =
new MetaDataKey<ConcurrentMap<String, ConcurrentMap<IKey, IWebSocketConnection>>>()
{
};
@Override
public IWebSocketConnection getConnection(Application application, String sessionId, IKey key)
{
Args.notNull(application, "application");
Args.notNull(sessionId, "sessionId");
Args.notNull(key, "key");
IWebSocketConnection connection = null;
ConcurrentMap<String, ConcurrentMap<IKey, IWebSocketConnection>> connectionsBySession = application.getMetaData(KEY);
if (connectionsBySession != null)
{
ConcurrentMap<IKey, IWebSocketConnection> connectionsByPage = connectionsBySession.get(sessionId);
if (connectionsByPage != null)
{
connection = connectionsByPage.get(key);
}
}
return connection;
}
/**
* Returns a collection of currently active websockets. The connections might close at any time.
*
* @param application
* The application
* @return a collection of currently active websockets
*/
public Collection<IWebSocketConnection> getConnections(Application application)
{
Args.notNull(application, "application");
Collection<IWebSocketConnection> connections = new ArrayList<>();
ConcurrentMap<String, ConcurrentMap<IKey, IWebSocketConnection>> connectionsBySession = application.getMetaData(KEY);
if (connectionsBySession != null)
{
for (ConcurrentMap<IKey, IWebSocketConnection> connectionsByPage : connectionsBySession.values())
{
connections.addAll(connectionsByPage.values());
}
}
return connections;
}
@Override
public void setConnection(Application application, String sessionId, IKey key, IWebSocketConnection connection)
{
Args.notNull(application, "application");
Args.notNull(sessionId, "sessionId");
Args.notNull(key, "key");
ConcurrentMap<String, ConcurrentMap<IKey, IWebSocketConnection>> connectionsBySession = application.getMetaData(KEY);
if (connectionsBySession == null)
{
synchronized (KEY)
{
connectionsBySession = application.getMetaData(KEY);
if (connectionsBySession == null)
{
connectionsBySession = Generics.newConcurrentHashMap();
application.setMetaData(KEY, connectionsBySession);
}
}
}
ConcurrentMap<IKey, IWebSocketConnection> connectionsByPage = connectionsBySession.get(sessionId);
if (connectionsByPage == null && connection != null)
{
connectionsByPage = connectionsBySession.get(sessionId);
if (connectionsByPage == null)
{
connectionsByPage = Generics.newConcurrentHashMap();
ConcurrentMap<IKey, IWebSocketConnection> old = connectionsBySession.putIfAbsent(sessionId, connectionsByPage);
if (old != null)
{
connectionsByPage = old;
}
}
}
if (connection != null)
{
connectionsByPage.put(key, connection);
}
else if (connectionsByPage != null)
{
connectionsByPage.remove(key);
if (connectionsByPage.isEmpty())
{
connectionsBySession.remove(sessionId);
}
}
}
@Override
public void removeConnection(Application application, String sessionId, IKey key)
{
setConnection(application, sessionId, key, null);
}
}