| /* |
| * 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. |
| */ |
| |
| using System; |
| using System.Collections.Generic; |
| using System.Linq; |
| using System.Threading; |
| |
| namespace Org.Apache.Rocketmq |
| { |
| internal sealed class SubscriptionLoadBalancer |
| { |
| private static readonly Random Random = new Random(); |
| |
| private readonly List<MessageQueue> _messageQueues; |
| private int _index; |
| |
| public SubscriptionLoadBalancer(TopicRouteData topicRouteData) : this(Random.Next(), topicRouteData) |
| { |
| } |
| |
| private SubscriptionLoadBalancer(int index, TopicRouteData topicRouteData) |
| { |
| _index = index; |
| _messageQueues = new List<MessageQueue>(); |
| foreach (var mq in topicRouteData.MessageQueues.Where(mq => PermissionHelper.IsReadable(mq.Permission)) |
| .Where(mq => Utilities.MasterBrokerId == mq.Broker.Id)) |
| { |
| _messageQueues.Add(mq); |
| } |
| } |
| |
| internal SubscriptionLoadBalancer Update(TopicRouteData topicRouteData) |
| { |
| return new SubscriptionLoadBalancer(_index, topicRouteData); |
| } |
| |
| public MessageQueue TakeMessageQueue() |
| { |
| var next = Interlocked.Increment(ref _index); |
| var index = Utilities.GetPositiveMod(next, _messageQueues.Count); |
| return _messageQueues[index]; |
| } |
| } |
| } |