| /* |
| * |
| * 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 java.util.Iterator; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| |
| public class AssignedConsumerMessageGroupManager implements MessageGroupManager |
| { |
| private static final Logger _logger = LoggerFactory.getLogger(AssignedConsumerMessageGroupManager.class); |
| |
| |
| private final String _groupId; |
| private final ConcurrentMap<Integer, QueueConsumer<?,?>> _groupMap = new ConcurrentHashMap<>(); |
| private final int _groupMask; |
| |
| AssignedConsumerMessageGroupManager(final String groupId, final int maxGroups) |
| { |
| _groupId = groupId; |
| _groupMask = pow2(maxGroups)-1; |
| } |
| |
| private static int pow2(final int i) |
| { |
| int val = 1; |
| while(val < i) |
| { |
| val<<=1; |
| } |
| return val; |
| } |
| |
| public boolean mightAssign(final QueueEntry entry, QueueConsumer sub) |
| { |
| Object groupVal = entry.getMessage().getMessageHeader().getHeader(_groupId); |
| |
| if(groupVal == null) |
| { |
| return true; |
| } |
| else |
| { |
| QueueConsumer<?,?> assignedSub = _groupMap.get(groupVal.hashCode() & _groupMask); |
| return assignedSub == null || assignedSub == sub; |
| } |
| } |
| |
| public boolean acceptMessage(QueueConsumer<?,?> sub, QueueEntry entry) |
| { |
| return assignMessage(sub, entry) && entry.acquire(sub); |
| } |
| |
| private boolean assignMessage(QueueConsumer<?,?> sub, QueueEntry entry) |
| { |
| Object groupVal = entry.getMessage().getMessageHeader().getHeader(_groupId); |
| if(groupVal == null) |
| { |
| return true; |
| } |
| else |
| { |
| Integer group = groupVal.hashCode() & _groupMask; |
| QueueConsumer<?,?> assignedSub = _groupMap.get(group); |
| if(assignedSub == sub) |
| { |
| return true; |
| } |
| else |
| { |
| if(assignedSub == null) |
| { |
| _logger.debug("Assigning group {} to sub {}", groupVal, sub); |
| assignedSub = _groupMap.putIfAbsent(group, sub); |
| return assignedSub == null || assignedSub == sub; |
| } |
| else |
| { |
| return false; |
| } |
| } |
| } |
| } |
| |
| public QueueEntry findEarliestAssignedAvailableEntry(QueueConsumer<?,?> sub) |
| { |
| EntryFinder visitor = new EntryFinder(sub); |
| sub.getQueue().visit(visitor); |
| return visitor.getEntry(); |
| } |
| |
| private class EntryFinder implements QueueEntryVisitor |
| { |
| private QueueEntry _entry; |
| private QueueConsumer<?,?> _sub; |
| |
| EntryFinder(final QueueConsumer<?, ?> sub) |
| { |
| _sub = sub; |
| } |
| |
| public boolean visit(final QueueEntry entry) |
| { |
| if(!entry.isAvailable()) |
| { |
| return false; |
| } |
| |
| Object groupId = entry.getMessage().getMessageHeader().getHeader(_groupId); |
| if(groupId == null) |
| { |
| return false; |
| } |
| |
| Integer group = groupId.hashCode() & _groupMask; |
| QueueConsumer<?,?> assignedSub = _groupMap.get(group); |
| if(assignedSub == _sub) |
| { |
| _entry = entry; |
| return true; |
| } |
| else |
| { |
| return false; |
| } |
| } |
| |
| public QueueEntry getEntry() |
| { |
| return _entry; |
| } |
| } |
| |
| public void clearAssignments(QueueConsumer<?,?> sub) |
| { |
| Iterator<QueueConsumer<?,?>> subIter = _groupMap.values().iterator(); |
| while(subIter.hasNext()) |
| { |
| if(subIter.next() == sub) |
| { |
| subIter.remove(); |
| } |
| } |
| } |
| } |