content: /**
   * 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.activemq.transport.ws;
  
  import java.io.IOException;
  import java.security.cert.X509Certificate;
  import java.util.Map;
  import java.util.concurrent.CountDownLatch;
  import java.util.concurrent.locks.ReentrantLock;
  
  import org.apache.activemq.broker.BrokerService;
  import org.apache.activemq.broker.BrokerServiceAware;
  import org.apache.activemq.command.Command;
  import org.apache.activemq.jms.pool.IntrospectionSupport;
  import org.apache.activemq.transport.TransportSupport;
  import org.apache.activemq.transport.mqtt.MQTTInactivityMonitor;
  import org.apache.activemq.transport.mqtt.MQTTProtocolConverter;
  import org.apache.activemq.transport.mqtt.MQTTTransport;
  import org.apache.activemq.transport.mqtt.MQTTWireFormat;
  import org.apache.activemq.util.IOExceptionSupport;
  import org.apache.activemq.util.ServiceStopper;
  import org.fusesource.mqtt.codec.MQTTFrame;
  
  public abstract class AbstractMQTTSocket extends TransportSupport implements MQTTTransport, BrokerServiceAware {
  
      protected ReentrantLock protocolLock = new ReentrantLock();
      protected volatile MQTTProtocolConverter protocolConverter = null;
      protected MQTTWireFormat wireFormat = new MQTTWireFormat();
      protected final MQTTInactivityMonitor mqttInactivityMonitor = new MQTTInactivityMonitor(this, wireFormat);
      protected final CountDownLatch socketTransportStarted = new CountDownLatch(1);
      protected BrokerService brokerService;
      protected volatile int receiveCounter;
      protected final String remoteAddress;
      protected X509Certificate[] peerCertificates;
      private Map<String, Object> transportOptions;
  
      public AbstractMQTTSocket(String remoteAddress) {
          super();
          this.remoteAddress = remoteAddress;
      }
  
      @Override
      public void oneway(Object command) throws IOException {
          protocolLock.lock();
          try {
              getProtocolConverter().onActiveMQCommand((Command)command);
          } catch (Exception e) {
              onException(IOExceptionSupport.create(e));
          } finally {
              protocolLock.unlock();
          }
      }
  
      @Override
      public void sendToActiveMQ(Command command) {
          protocolLock.lock();
          try {
              doConsume(command);
          } finally {
              protocolLock.unlock();
          }
      }
  
      @Override
      protected void doStop(ServiceStopper stopper) throws Exception {
          mqttInactivityMonitor.stop();
          handleStopped();
      }
  
      @Override
      protected void doStart() throws Exception {
          socketTransportStarted.countDown();
          mqttInactivityMonitor.setTransportListener(getTransportListener());
          mqttInactivityMonitor.startConnectChecker(wireFormat.getConnectAttemptTimeout());
      }
  
      //----- Abstract methods for subclasses to implement ---------------------//
  
      @Override
      public abstract void sendToMQTT(MQTTFrame command) throws IOException;
  
      /**
       * Called when the transport is stopping to allow the dervied classes
       * a chance to close WebSocket resources.
       *
       * @throws IOException if an error occurs during the stop.
       */
      public abstract void handleStopped() throws IOException;
  
      //----- Accessor methods -------------------------------------------------//
  
      @Override
      public MQTTInactivityMonitor getInactivityMonitor() {
          return mqttInactivityMonitor;
      }
  
      @Override
      public MQTTWireFormat getWireFormat() {
          return wireFormat;
      }
  
      @Override
      public String getRemoteAddress() {
          return remoteAddress;
      }
  
      @Override
      public int getReceiveCounter() {
          return receiveCounter;
      }
  
      @Override
      public X509Certificate[] getPeerCertificates() {
          return peerCertificates;
      }
  
      @Override
      public void setPeerCertificates(X509Certificate[] certificates) {
          this.peerCertificates = certificates;
      }
  
      @Override
      public void setBrokerService(BrokerService brokerService) {
          this.brokerService = brokerService;
      }
  
      //----- Internal support methods -----------------------------------------//
  
      protected MQTTProtocolConverter getProtocolConverter() {
          if (protocolConverter == null) {
              synchronized(this) {
                  if (protocolConverter == null) {
                      MQTTProtocolConverter newProtocolConverter = new MQTTProtocolConverter(this, brokerService);
                      IntrospectionSupport.setProperties(newProtocolConverter, transportOptions);
                      protocolConverter = newProtocolConverter;
                  }
              }
          }
          return protocolConverter;
      }
  
      protected boolean transportStartedAtLeastOnce() {
          return socketTransportStarted.getCount() == 0;
      }
  
      public void setTransportOptions(Map<String, Object> transportOptions) {
          this.transportOptions = transportOptions;
      }
  }
  