Add extension for RPC calls; replace locks; Refactored storage in Managed Client

2026-10-16 01:03:01 +08:00 · 2017-12-04 10:21:37 +01:00
parent 0ee3c8e135
commit d12d2648b7
31 changed files with 690 additions and 307 deletions
@@ -0,0 +1,101 @@
+using System;
+using System.Collections.Concurrent;
+using System.Threading.Tasks;
+using MQTTnet.Client;
+using MQTTnet.Internal;
+using MQTTnet.Protocol;
+
+namespace MQTTnet.Extensions.Rpc
+{
+    public sealed class MqttRpcClient : IDisposable
+    {
+        private const string ResponseTopic = "$RPC/+/+/response";
+        private readonly ConcurrentDictionary<string, TaskCompletionSource<byte[]>> _waitingCalls = new ConcurrentDictionary<string, TaskCompletionSource<byte[]>>();
+        private readonly IMqttClient _mqttClient;
+        private bool _isEnabled;
+
+        public MqttRpcClient(IMqttClient mqttClient)
+        {
+            _mqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
+
+            _mqttClient.ApplicationMessageReceived += OnApplicationMessageReceived;
+        }
+
+        public async Task EnableAsync()
+        {
+            await _mqttClient.SubscribeAsync(new TopicFilterBuilder().WithTopic(ResponseTopic).WithAtLeastOnceQoS().Build());
+            _isEnabled = true;
+        }
+
+        public async Task DisableAsync()
+        {
+            await _mqttClient.UnsubscribeAsync(ResponseTopic);
+            _isEnabled = false;
+        }
+
+        public async Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
+        {
+            if (methodName == null) throw new ArgumentNullException(nameof(methodName));
+
+            if (methodName.Contains("/") || methodName.Contains("+") || methodName.Contains("#"))
+            {
+                throw new ArgumentException("The method name cannot contain /, + or #.");
+            }
+
+            if (!_isEnabled)
+            {
+                throw new InvalidOperationException("The RPC client is not enabled.");
+            }
+
+            var requestTopic = $"$MQTTnet.RPC/{Guid.NewGuid():N}/{methodName}";
+            var responseTopic = requestTopic + "/response";
+
+            var requestMessage = new MqttApplicationMessageBuilder()
+                .WithTopic(requestTopic)
+                .WithPayload(payload)
+                .WithQualityOfServiceLevel(qualityOfServiceLevel)
+                .Build();
+
+            try
+            {
+                var tcs = new TaskCompletionSource<byte[]>();
+                if (!_waitingCalls.TryAdd(responseTopic, tcs))
+                {
+                    throw new InvalidOperationException();
+                }
+
+                await _mqttClient.PublishAsync(requestMessage);
+                return await tcs.Task.TimeoutAfter(timeout);
+            }
+            finally
+            {
+                _waitingCalls.TryRemove(responseTopic, out _);
+            }
+        }
+
+        private void OnApplicationMessageReceived(object sender, MqttApplicationMessageReceivedEventArgs eventArgs)
+        {
+            if (!_waitingCalls.TryRemove(eventArgs.ApplicationMessage.Topic, out TaskCompletionSource<byte[]> tcs))
+            {
+                return;
+            }
+
+            if (tcs.Task.IsCompleted || tcs.Task.IsCanceled)
+            {
+                return;
+            }
+
+            tcs.TrySetResult(eventArgs.ApplicationMessage.Payload);
+        }
+
+        public void Dispose()
+        {
+            foreach (var tcs in _waitingCalls)
+            {
+                tcs.Value.SetCanceled();
+            }
+
+            _waitingCalls.Clear();
+        }
+    }
+}