| /* |
| * 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 |
| { |
| public class PublishingLoadBalancer |
| { |
| private static readonly Random Random = new Random(); |
| |
| private readonly List<MessageQueue> _messageQueues; |
| private int _index; |
| |
| public PublishingLoadBalancer(TopicRouteData topicRouteData) : this(Random.Next(), topicRouteData) |
| { |
| } |
| |
| private PublishingLoadBalancer(int index, TopicRouteData topicRouteData) |
| { |
| _index = index; |
| _messageQueues = new List<MessageQueue>(); |
| foreach (var mq in topicRouteData.MessageQueues.Where(messageQueue => |
| PermissionHelper.IsWritable(messageQueue.Permission) && |
| Utilities.MasterBrokerId == messageQueue.Broker.Id)) |
| { |
| _messageQueues.Add(mq); |
| } |
| } |
| |
| internal PublishingLoadBalancer Update(TopicRouteData topicRouteData) |
| { |
| return new PublishingLoadBalancer(_index, topicRouteData); |
| } |
| |
| |
| public MessageQueue TakeMessageQueueByMessageGroup(string messageGroup) |
| { |
| // TODO: use SipHash24 algorithm |
| var index = Utilities.GetPositiveMod(messageGroup.GetHashCode(), _messageQueues.Count); |
| return _messageQueues[index]; |
| } |
| |
| public List<MessageQueue> TakeMessageQueues(HashSet<Endpoints> excluded, int count) |
| { |
| var next = Interlocked.Increment(ref _index); |
| var candidates = new List<MessageQueue>(); |
| var candidateBrokerNames = new HashSet<string>(); |
| |
| foreach (var mq in _messageQueues.Select(_ => Utilities.GetPositiveMod(next++, _messageQueues.Count)) |
| .Select(index => _messageQueues[index])) |
| { |
| if (!excluded.Contains(mq.Broker.Endpoints) && !candidateBrokerNames.Contains(mq.Broker.Name)) |
| { |
| candidateBrokerNames.Add(mq.Broker.Name); |
| candidates.Add(mq); |
| } |
| |
| if (candidates.Count >= count) |
| { |
| return candidates; |
| } |
| } |
| |
| if (candidates.Count != 0) |
| { |
| return candidates; |
| } |
| |
| foreach (var mq in _messageQueues.Select(_ => Utilities.GetPositiveMod(next++, _messageQueues.Count)) |
| .Select(positiveMod => _messageQueues[positiveMod])) |
| { |
| if (!candidateBrokerNames.Contains(mq.Broker.Name)) |
| { |
| candidateBrokerNames.Add(mq.Broker.Name); |
| candidates.Add(mq); |
| } |
| |
| if (candidates.Count >= count) |
| { |
| break; |
| } |
| } |
| |
| return candidates; |
| } |
| } |
| } |