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.cursors;
  
  import java.util.Map;
  
  import org.apache.activemq.broker.region.MessageReference;
  import org.apache.activemq.command.MessageId;
  import org.apache.activemq.management.SizeStatisticImpl;
  
  /**
   *
   *
   */
  public class PendingMessageHelper {
  
      private final Map<MessageId, PendingNode> map;
      private final SizeStatisticImpl messageSize;
  
      public PendingMessageHelper(Map<MessageId, PendingNode> map,
              SizeStatisticImpl messageSize) {
          super();
          this.map = map;
          this.messageSize = messageSize;
      }
  
      public void addToMap(MessageReference message, PendingNode node) {
          PendingNode previous = this.map.put(message.getMessageId(), node);
          if (previous != null) {
              try {
                  messageSize.addSize(-previous.getMessage().getSize());
              } catch (Exception e) {
                //expected for NullMessageReference
              }
          }
          try {
              messageSize.addSize(message.getSize());
          } catch (Exception e) {
            //expected for NullMessageReference
          }
      }
  
      public PendingNode removeFromMap(MessageReference message) {
          PendingNode removed = this.map.remove(message.getMessageId());
          if (removed != null) {
              try {
                  messageSize.addSize(-removed.getMessage().getSize());
              } catch (Exception e) {
                  //expected for NullMessageReference
              }
          }
          return removed;
      }
  }
  