/*
* 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.tuscany.sca.host.corba.jse.tns;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.logging.Logger;
import org.apache.tuscany.sca.host.corba.CorbaHost;
import org.apache.tuscany.sca.host.corba.CorbaHostException;
import org.apache.tuscany.sca.host.corba.CorbanameURL;
import org.apache.tuscany.sca.host.corba.SocketUtil;
import org.apache.tuscany.sca.host.corba.jse.DefaultCorbaHost;
import org.apache.tuscany.sca.host.corba.naming.TransientNameServer;
import org.apache.tuscany.sca.host.corba.naming.TransientNameService;
import org.omg.CORBA.Object;
/**
* @version $Rev$ $Date$
* Default implementation of CORBA host
*/
public class TnsDefaultCorbaHost implements CorbaHost {
private static final Logger logger = Logger.getLogger(TnsDefaultCorbaHost.class.getName());
private Map<Integer, TransientNameServer> localServers = new ConcurrentHashMap<Integer, TransientNameServer>();
private Map<Integer, Integer> clientsCount = new ConcurrentHashMap<Integer, Integer>();
private CorbaHost targetHost = new DefaultCorbaHost();
public void registerServant(String uri, Object servantObject) throws CorbaHostException {
CorbanameURL details = new CorbanameURL(uri);
if (SocketUtil.isLocalhost(details.getHost())) {
createLocalNameServer(details.getPort());
}
targetHost.registerServant(uri, servantObject);
}
public void unregisterServant(String uri) throws CorbaHostException {
targetHost.unregisterServant(uri);
CorbanameURL details = new CorbanameURL(uri);
if (SocketUtil.isLocalhost(details.getHost())) {
releaseLocalNameServer(details.getPort());
}
}
public Object lookup(String uri) throws CorbaHostException {
return targetHost.lookup(uri);
}
/**
* Starts transient name server under given port. If TNS was previously
* spawned it increments clients counter.
*/
synchronized private void createLocalNameServer(int port) throws CorbaHostException {
int useCount = clientsCount.containsKey(port) ? clientsCount.get(port) : 0;
// no server previously spawned
if (useCount == 0) {
TransientNameServer server =
new TransientNameServer("localhost", port, TransientNameService.DEFAULT_SERVICE_NAME);
Thread thread = server.start();
if (thread == null) {
throw new CorbaHostException("TransientNameServer couldn't be started");
} else {
localServers.put(port, server);
}
}
clientsCount.put(port, ++useCount);
}
/**
* Stops transient name server if there is only one client left using such
* TNS. Decrements clients counter if TNS is used by 2 or more clients.
*/
synchronized private void releaseLocalNameServer(int port) throws CorbaHostException {
int useCount = clientsCount.containsKey(port) ? clientsCount.get(port) : 0;
if (useCount == 1) {
// last client executed stop, cleaning up
TransientNameServer server = localServers.get(port);
if (server != null) {
server.stop();
clientsCount.remove(port);
localServers.remove(port);
} else {
logger.warning("Local name server on port " + port + " was null!");
}
} else if (useCount > 1) {
clientsCount.put(port, --useCount);
} else {
logger.warning("Tried to release non existing local name server on port " + port);
}
}
public void stop() {
for (TransientNameServer tns : localServers.values()) {
tns.stop();
}
}
}