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.amqp.protocol;
  
  import org.apache.activemq.command.LocalTransactionId;
  import org.apache.activemq.transport.amqp.AmqpProtocolException;
  import org.apache.qpid.proton.amqp.transport.ReceiverSettleMode;
  import org.apache.qpid.proton.engine.Delivery;
  import org.apache.qpid.proton.engine.Receiver;
  import org.fusesource.hawtbuf.Buffer;
  import org.fusesource.hawtbuf.ByteArrayOutputStream;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Abstract base that provides common services for AMQP Receiver types.
   */
  public abstract class AmqpAbstractReceiver extends AmqpAbstractLink<Receiver> {
  
      private static final Logger LOG = LoggerFactory.getLogger(AmqpAbstractReceiver.class);
  
      protected ByteArrayOutputStream current = new ByteArrayOutputStream();
      protected final byte[] recvBuffer = new byte[1024 * 8];
      protected final int configuredCredit;
  
      /**
       * Handle create of new AMQP Receiver instance.
       *
       * @param session
       *        the AmqpSession that servers as the parent of this Link.
       * @param endpoint
       *        the Receiver endpoint being managed by this class.
       */
      public AmqpAbstractReceiver(AmqpSession session, Receiver endpoint) {
          super(session, endpoint);
          this.configuredCredit = session.getConnection().getConfiguredReceiverCredit();
  
          // We don't support second so enforce it as First and let remote decide what to do
          this.endpoint.setReceiverSettleMode(ReceiverSettleMode.FIRST);
  
          // Match what the sender mode is
          this.endpoint.setSenderSettleMode(endpoint.getRemoteSenderSettleMode());
      }
  
      @Override
      public void detach() {
      }
  
      @Override
      public void flow() throws Exception {
      }
  
      /**
       * Returns the amount of receiver credit that has been configured for this AMQP
       * transport.  If no value was configured on the TransportConnector URI then a
       * sensible default is used.
       *
       * @return the configured receiver credit to grant.
       */
      public int getConfiguredReceiverCredit() {
          return configuredCredit;
      }
  
      /**
       * Provide the receiver endpoint with the given amount of credits.
       *
       * @param credits
       *        the credit value to pass on to the wrapped Receiver.
       */
      public void flow(int credits) {
          getEndpoint().flow(credits);
      }
  
      @Override
      public void commit(LocalTransactionId txnId) throws Exception {
      }
  
      @Override
      public void rollback(LocalTransactionId txnId) throws Exception {
      }
  
      @Override
      public void delivery(Delivery delivery) throws Exception {
  
          if (!delivery.isReadable()) {
              LOG.debug("Delivery was not readable!");
              return;
          }
  
          if (current == null) {
              current = new ByteArrayOutputStream();
          }
  
          int count;
          while ((count = getEndpoint().recv(recvBuffer, 0, recvBuffer.length)) > 0) {
              current.write(recvBuffer, 0, count);
  
              if (current.size() > session.getMaxFrameSize()) {
                  throw new AmqpProtocolException("Frame size of " + current.size() + " larger than max allowed " + session.getMaxFrameSize());
              }
          }
  
          // Expecting more deliveries..
          if (count == 0) {
              return;
          }
  
          try {
              processDelivery(delivery, current.toBuffer());
          } finally {
              getEndpoint().advance();
              current = null;
          }
      }
  
      protected abstract void processDelivery(Delivery delivery, Buffer deliveryBytes) throws Exception;
  
  }
  