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.broker.region;
  
  import org.apache.activemq.command.ConsumerId;
  import org.apache.activemq.command.Message;
  import org.apache.activemq.command.MessageId;
  
  /**
   * Keeps track of a message that is flowing through the Broker. This object may
   * hold a hard reference to the message or only hold the id of the message if
   * the message has been persisted on in a MessageStore.
   *
   *
   */
  public class IndirectMessageReference implements QueueMessageReference {
  
      /** The subscription that has locked the message */
      private LockOwner lockOwner;
      /** Has the message been dropped? */
      private boolean dropped;
      /** Has the message been acked? */
      private boolean acked;
      /** Direct reference to the message */
      private final Message message;
      private final MessageId messageId;
  
      /**
       * @param message
       */
      public IndirectMessageReference(final Message message) {
          this.message = message;
          this.messageId = message.getMessageId().copy();
          message.getMessageId();
          message.getGroupID();
          message.getGroupSequence();
      }
  
      @Override
      public Message getMessageHardRef() {
          return message;
      }
  
      @Override
      public int getReferenceCount() {
          return message.getReferenceCount();
      }
  
      @Override
      public int incrementReferenceCount() {
          return message.incrementReferenceCount();
      }
  
      @Override
      public int decrementReferenceCount() {
          return message.decrementReferenceCount();
      }
  
      @Override
      public Message getMessage() {
          return message;
      }
  
      @Override
      public String toString() {
          return "Message " + message.getMessageId() + " dropped=" + dropped + " acked=" + acked + " locked=" + (lockOwner != null);
      }
  
      @Override
      public void incrementRedeliveryCounter() {
          message.incrementRedeliveryCounter();
      }
  
      @Override
      public synchronized boolean isDropped() {
          return dropped;
      }
  
      @Override
      public synchronized void drop() {
          dropped = true;
          lockOwner = null;
          message.decrementReferenceCount();
      }
  
      /**
       * Check if the message has already been dropped before
       * dropping. Return true if dropped, else false.
       * This method exists so that this can be done atomically
       * under the intrinisic lock
       */
      @Override
      public synchronized boolean dropIfLive() {
          if (isDropped()) {
              return false;
          } else {
              drop();
              return true;
          }
      }
  
      @Override
      public boolean lock(LockOwner subscription) {
          synchronized (this) {
              if (dropped || lockOwner != null) {
                  return false;
              }
              lockOwner = subscription;
              return true;
          }
      }
  
      @Override
      public synchronized boolean unlock() {
          boolean result = lockOwner != null;
          lockOwner = null;
          return result;
      }
  
      @Override
      public synchronized LockOwner getLockOwner() {
          return lockOwner;
      }
  
      @Override
      public int getRedeliveryCounter() {
          return message.getRedeliveryCounter();
      }
  
      @Override
      public MessageId getMessageId() {
          return messageId;
      }
  
      @Override
      public Message.MessageDestination getRegionDestination() {
          return message.getRegionDestination();
      }
  
      @Override
      public boolean isPersistent() {
          return message.isPersistent();
      }
  
      public synchronized boolean isLocked() {
          return lockOwner != null;
      }
  
      @Override
      public synchronized boolean isAcked() {
          return acked;
      }
  
      @Override
      public synchronized void setAcked(boolean b) {
          acked = b;
      }
  
      @Override
      public String getGroupID() {
          return message.getGroupID();
      }
  
      @Override
      public int getGroupSequence() {
          return message.getGroupSequence();
      }
  
      @Override
      public ConsumerId getTargetConsumerId() {
          return message.getTargetConsumerId();
      }
  
      @Override
      public long getExpiration() {
          return message.getExpiration();
      }
  
      @Override
      public boolean isExpired() {
          return message.isExpired();
      }
  
      @Override
      public synchronized int getSize() {
         return message.getSize();
      }
  
      @Override
      public boolean isAdvisory() {
         return message.isAdvisory();
      }
  
      @Override
      public boolean canProcessAsExpired() {
          return message.canProcessAsExpired();
      }
  }
  