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.policy;
  
  import java.io.IOException;
  import java.util.Iterator;
  import java.util.LinkedList;
  
  import org.apache.activemq.broker.region.MessageReference;
  
  /**
   * An eviction strategy which evicts the oldest message with the lowest priority first.
   * 
   * @org.apache.xbean.XBean
   * 
   * messageEvictionStrategy
   */
  public class OldestMessageWithLowestPriorityEvictionStrategy extends MessageEvictionStrategySupport {
  
      public MessageReference[] evictMessages(LinkedList messages) throws IOException {
          byte lowestPriority = Byte.MAX_VALUE;
          int pivot = 0;
          Iterator iter = messages.iterator();
          for (int i = 0; iter.hasNext(); i++) {
              MessageReference reference = (MessageReference) iter.next();
              byte priority = reference.getMessage().getPriority();
              if (priority < lowestPriority) {
                  lowestPriority = priority;
                  pivot = i;
              }
          }
          return new MessageReference[] {(MessageReference) messages.remove(pivot)};
      }
  }
  