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;
  
  import java.util.concurrent.atomic.AtomicInteger;
  
  import jakarta.jms.ConnectionConsumer;
  import jakarta.jms.IllegalStateException;
  import jakarta.jms.JMSException;
  import jakarta.jms.ServerSession;
  import jakarta.jms.ServerSessionPool;
  import jakarta.jms.Session;
  
  import org.apache.activemq.command.ConsumerInfo;
  import org.apache.activemq.command.MessageDispatch;
  
  /**
   * For application servers, <CODE>Connection</CODE> objects provide a special
   * facility for creating a <CODE>ConnectionConsumer</CODE> (optional). The
   * messages it is to consume are specified by a <CODE>Destination</CODE> and a
   * message selector. In addition, a <CODE>ConnectionConsumer</CODE> must be
   * given a <CODE>ServerSessionPool</CODE> to use for processing its messages.
   * <p/>
   * <P>
   * Normally, when traffic is light, a <CODE>ConnectionConsumer</CODE> gets a
   * <CODE>ServerSession</CODE> from its pool, loads it with a single message,
   * and starts it. As traffic picks up, messages can back up. If this happens, a
   * <CODE>ConnectionConsumer</CODE> can load each <CODE>ServerSession</CODE>
   * with more than one message. This reduces the thread context switches and
   * minimizes resource use at the expense of some serialization of message
   * processing.
   * 
   * @see jakarta.jms.Connection#createConnectionConsumer
   * @see jakarta.jms.Connection#createDurableConnectionConsumer
   * @see jakarta.jms.QueueConnection#createConnectionConsumer
   * @see jakarta.jms.TopicConnection#createConnectionConsumer
   * @see jakarta.jms.TopicConnection#createDurableConnectionConsumer
   */
  
  public class ActiveMQConnectionConsumer implements ConnectionConsumer, ActiveMQDispatcher {
  
      private ActiveMQConnection connection;
      private ServerSessionPool sessionPool;
      private ConsumerInfo consumerInfo;
      private boolean closed;
  
      /**
       * Create a ConnectionConsumer
       * 
       * @param theConnection
       * @param theSessionPool
       * @param theConsumerInfo
       * @throws JMSException
       */
      protected ActiveMQConnectionConsumer(ActiveMQConnection theConnection, ServerSessionPool theSessionPool, ConsumerInfo theConsumerInfo) throws JMSException {
          this.connection = theConnection;
          this.sessionPool = theSessionPool;
          this.consumerInfo = theConsumerInfo;
  
          this.connection.addConnectionConsumer(this);
          this.connection.addDispatcher(consumerInfo.getConsumerId(), this);
          this.connection.syncSendPacket(this.consumerInfo);
      }
  
      /**
       * Gets the server session pool associated with this connection consumer.
       * 
       * @return the server session pool used by this connection consumer
       * @throws JMSException if the JMS provider fails to get the server session
       *                 pool associated with this consumer due to some internal
       *                 error.
       */
  
      public ServerSessionPool getServerSessionPool() throws JMSException {
          if (closed) {
              throw new IllegalStateException("The Connection Consumer is closed");
          }
          return this.sessionPool;
      }
  
      /**
       * Closes the connection consumer. <p/>
       * <P>
       * Since a provider may allocate some resources on behalf of a connection
       * consumer outside the Java virtual machine, clients should close these
       * resources when they are not needed. Relying on garbage collection to
       * eventually reclaim these resources may not be timely enough.
       * 
       * @throws JMSException
       */
  
      public void close() throws JMSException {
          if (!closed) {
              dispose();
              this.connection.asyncSendPacket(this.consumerInfo.createRemoveCommand());
          }
  
      }
  
      public void dispose() {
          if (!closed) {
              this.connection.removeDispatcher(consumerInfo.getConsumerId());
              this.connection.removeConnectionConsumer(this);
              closed = true;
          }
      }
  
      public void dispatch(MessageDispatch messageDispatch) {
          try {
              messageDispatch.setConsumer(this);
  
              ServerSession serverSession = sessionPool.getServerSession();
              Session s = serverSession.getSession();
              ActiveMQSession session = null;
  
              if (s instanceof ActiveMQSession) {
                  session = (ActiveMQSession)s;
              } else if (s instanceof ActiveMQTopicSession) {
                  ActiveMQTopicSession topicSession = (ActiveMQTopicSession)s;
                  session = (ActiveMQSession)topicSession.getNext();
              } else if (s instanceof ActiveMQQueueSession) {
                  ActiveMQQueueSession queueSession = (ActiveMQQueueSession)s;
                  session = (ActiveMQSession)queueSession.getNext();
              } else {
                  connection.onClientInternalException(new JMSException("Session pool provided an invalid session type: " + s.getClass()));
                  return;
              }
  
              session.dispatch(messageDispatch);
              serverSession.start();
          } catch (JMSException e) {
              connection.onAsyncException(e);
          }
      }
  
      public String toString() {
          return "ActiveMQConnectionConsumer { value=" + consumerInfo.getConsumerId() + " }";
      }
  
      public void clearMessagesInProgress(AtomicInteger transportInterruptionProcessingComplete) {
          // future: may want to deal with rollback of in progress messages to track re deliveries
          // before indicating that all is complete.        
      }
  
      public ConsumerInfo getConsumerInfo() {
          return consumerInfo;
      }
  }
  