| /* |
| * |
| * 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.qpid.server.queue; |
| |
| import org.apache.qpid.framing.CommonContentHeaderProperties; |
| import org.apache.qpid.AMQException; |
| |
| public class PriorityQueueList implements QueueEntryList |
| { |
| private final AMQQueue _queue; |
| private final QueueEntryList[] _priorityLists; |
| private final int _priorities; |
| private final int _priorityOffset; |
| |
| public PriorityQueueList(AMQQueue queue, int priorities) |
| { |
| _queue = queue; |
| _priorityLists = new QueueEntryList[priorities]; |
| _priorities = priorities; |
| _priorityOffset = 5-((priorities + 1)/2); |
| for(int i = 0; i < priorities; i++) |
| { |
| _priorityLists[i] = new SimpleQueueEntryList(queue); |
| } |
| } |
| |
| public int getPriorities() |
| { |
| return _priorities; |
| } |
| |
| public AMQQueue getQueue() |
| { |
| return _queue; |
| } |
| |
| public QueueEntry add(AMQMessage message) |
| { |
| try |
| { |
| int index = ((CommonContentHeaderProperties)((message.getContentHeaderBody().properties))).getPriority() - _priorityOffset; |
| if(index >= _priorities) |
| { |
| index = _priorities-1; |
| } |
| else if(index < 0) |
| { |
| index = 0; |
| } |
| return _priorityLists[index].add(message); |
| } |
| catch (AMQException e) |
| { |
| // TODO - fix AMQ Exception |
| throw new RuntimeException(e); |
| } |
| |
| } |
| |
| public QueueEntry next(QueueEntry node) |
| { |
| QueueEntryImpl nodeImpl = (QueueEntryImpl)node; |
| QueueEntry next = nodeImpl.getNext(); |
| |
| if(next == null) |
| { |
| QueueEntryList nodeEntryList = nodeImpl.getQueueEntryList(); |
| int index; |
| for(index = _priorityLists.length-1; _priorityLists[index] != nodeEntryList; index--); |
| |
| while(next == null && index != 0) |
| { |
| index--; |
| next = ((QueueEntryImpl)_priorityLists[index].getHead()).getNext(); |
| } |
| |
| } |
| return next; |
| } |
| |
| private final class PriorityQueueEntryListIterator implements QueueEntryIterator |
| { |
| private final QueueEntryIterator[] _iterators = new QueueEntryIterator[ _priorityLists.length ]; |
| private QueueEntry _lastNode; |
| |
| PriorityQueueEntryListIterator() |
| { |
| for(int i = 0; i < _priorityLists.length; i++) |
| { |
| _iterators[i] = _priorityLists[i].iterator(); |
| } |
| _lastNode = _iterators[_iterators.length - 1].getNode(); |
| } |
| |
| |
| public boolean atTail() |
| { |
| for(int i = 0; i < _iterators.length; i++) |
| { |
| if(!_iterators[i].atTail()) |
| { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| public QueueEntry getNode() |
| { |
| return _lastNode; |
| } |
| |
| public boolean advance() |
| { |
| for(int i = _iterators.length-1; i >= 0; i--) |
| { |
| if(_iterators[i].advance()) |
| { |
| _lastNode = _iterators[i].getNode(); |
| return true; |
| } |
| } |
| return false; |
| } |
| } |
| |
| public QueueEntryIterator iterator() |
| { |
| return new PriorityQueueEntryListIterator(); |
| } |
| |
| public QueueEntry getHead() |
| { |
| return _priorityLists[_priorities-1].getHead(); |
| } |
| |
| static class Factory implements QueueEntryListFactory |
| { |
| private final int _priorities; |
| |
| Factory(int priorities) |
| { |
| _priorities = priorities; |
| } |
| |
| public QueueEntryList createQueueEntryList(AMQQueue queue) |
| { |
| return new PriorityQueueList(queue, _priorities); |
| } |
| } |
| } |