Fix issues in RPC extension.

Build/MQTTnet.Extensions.Rpc.nuspec

@@ -2,7 +2,7 @@
 <package >
   <metadata>
     <id>MQTTnet.Extensions.Rpc</id>
-    <version>2.6.0</version>
+    <version>2.7.4</version>
     <authors>Christian Kratky</authors>
     <owners>Christian Kratky</owners>
     <licenseUrl>https://github.com/chkr1011/MQTTnet/blob/master/LICENSE</licenseUrl>
@@ -12,36 +12,42 @@
     <description>This is a extension library which allows executing synchronous device calls including a response using MQTTnet.</description>
     <releaseNotes>* Initial version.
     </releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2017</copyright>
+    <copyright>Copyright Christian Kratky 2016-2018</copyright>
     <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 
     <dependencies>
       <group targetFramework="netstandard2.0">
-        <dependency id="MQTTnet" version="2.6.0-rc1" />
+        <dependency id="MQTTnet" version="2.7.4" />
       </group>
       <group targetFramework="netstandard1.3">
-        <dependency id="MQTTnet" version="2.6.0-rc1" />  
+        <dependency id="MQTTnet" version="2.7.4" />  
       </group>
-
       <group targetFramework="netstandard2.0">
-        <dependency id="MQTTnet" version="2.6.0-rc1" />
+        <dependency id="MQTTnet" version="2.7.4" />
       </group>
-      
       <group targetFramework="uap10.0">
-        <dependency id="MQTTnet" version="2.6.0-rc1" />
+        <dependency id="MQTTnet" version="2.7.4" />
       </group>
-        
       <group targetFramework="net452">
-        <dependency id="MQTTnet" version="2.6.0-rc1" />
+        <dependency id="MQTTnet" version="2.7.4" />
       </group>
-
       <group targetFramework="net461">
-        <dependency id="MQTTnet" version="2.6.0-rc1" />
+        <dependency id="MQTTnet" version="2.7.4" />
       </group>
     </dependencies>
   </metadata>
 
   <files>
+    <!-- .NET Standard 1.3 -->
+    <file src="..\Extensions\MQTTnet.Extensions.Rpc\bin\Release\MQTTnet.Extensions.Rpc.*" target="lib\netstandard1.3\"/>
+
     <!-- .NET Standard 2.0 -->
-    <file src="..\Frameworks\MQTTnet.AspNetCore\bin\Release\netstandard2.0\MQTTnet.AspNetCore.*" target="lib\netstandard2.0\"/>
+    <file src="..\Extensions\MQTTnet.Extensions.Rpc\bin\Release\MQTTnet.Extensions.Rpc.*" target="lib\netstandard2.0\"/>
+
+    <!-- Universal Windows -->
+    <file src="..\Extensions\MQTTnet.Extensions.Rpc\bin\Release\uap10.0\MQTTnet.Extensions.Rpc.*" target="lib\uap10.0\"/>
+
+    <!-- .NET Framework -->
+    <file src="..\Extensions\MQTTnet.Extensions.Rpc\bin\Release\net452\MQTTnet.Extensions.Rpc.*" target="lib\net452\"/>
+    <file src="..\Extensions\MQTTnet.Extensions.Rpc\bin\Release\net461\MQTTnet.Extensions.Rpc.*" target="lib\net461\"/>
   </files>
 </package>

Build/MQTTnet.nuspec

@@ -2,7 +2,7 @@
 <package >
   <metadata>
     <id>MQTTnet</id>
-    <version>2.7.4</version>
+    <version>2.7.5</version>
     <authors>Christian Kratky</authors>
     <owners>Christian Kratky</owners>
     <licenseUrl>https://github.com/chkr1011/MQTTnet/blob/master/LICENSE</licenseUrl>
@@ -10,47 +10,34 @@
     <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker).</description>
-    <releaseNotes> * [Client] Fixed a deadlock while the client disconnects.
+    <releaseNotes> * [Client] Added new overloads for the message builder.
-* [Client] Fixed broken support for protocol version 3.1.0.
-* [Server] The _MqttTcpServerAdapter_ is now added to the ASP.NET services.
-* [Server] _MqttServerAdapter_ is renamed to _MqttTcpServerAdapter_ (BREAKING CHANGE!).
-* [Server] The server no longer sends the will message of a client if the disconnect was clean (via _Disconnect_ packet).
-* [Server] The application message interceptor now allows closing the connection.
-* [Server] Added a new flag for the _ClientDisconnected_ event which contains a value indicating whether the disconnect was clean (via _Disconnect_ packet).
     </releaseNotes>
     <copyright>Copyright Christian Kratky 2016-2018</copyright>
     <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 
     <dependencies>
-
       <group targetFramework="netstandard1.3">
         <dependency id="NETStandard.Library" version="1.3.0" />
         <dependency id="System.Net.Security" version="4.3.2" />
         <dependency id="System.Net.WebSockets" version="4.3.0" />
         <dependency id="System.Net.WebSockets.Client" version="4.3.1" />      
       </group>
-
       <group targetFramework="netstandard2.0">
         <dependency id="NETStandard.Library" version="2.0.0" />
         <dependency id="System.Net.Security" version="4.3.2" />
         <dependency id="System.Net.WebSockets" version="4.3.0" />
         <dependency id="System.Net.WebSockets.Client" version="4.3.1" />
       </group>
-      
       <group targetFramework="uap10.0">
         <dependency id="Microsoft.NETCore.UniversalWindowsPlatform" version="5.4.1" />
       </group>
-        
       <group targetFramework="net452">
       </group>
-
       <group targetFramework="net461">
       </group>
-      
     </dependencies>
   </metadata>
 
   <files>
-    
     <!-- .NET Standard 1.3 -->
     <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\netstandard1.3\MQTTnet.*" target="lib\netstandard1.3\"/>
     
@@ -63,6 +50,5 @@
     <!-- .NET Framework -->
     <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\net452\MQTTnet.*" target="lib\net452\"/>
     <file src="..\Frameworks\MQTTnet.Netstandard\bin\Release\net461\MQTTnet.*" target="lib\net461\"/>   
-    
   </files>
 </package>

Extensions/MQTTnet.Extensions.Rpc/MqttRpcClient.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Concurrent;
+using System.Text;
 using System.Threading.Tasks;
 using MQTTnet.Client;
 using MQTTnet.Internal;
@@ -9,10 +10,8 @@ namespace MQTTnet.Extensions.Rpc
 {
     public sealed class MqttRpcClient : IDisposable
     {
-        private const string ResponseTopic = "$MQTTnet.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)
         {
@@ -21,16 +20,9 @@ namespace MQTTnet.Extensions.Rpc
             _mqttClient.ApplicationMessageReceived += OnApplicationMessageReceived;
         }
 
-        public async Task EnableAsync()
+        public Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
         {
-            await _mqttClient.SubscribeAsync(new TopicFilterBuilder().WithTopic(ResponseTopic).WithAtLeastOnceQoS().Build());
+            return ExecuteAsync(timeout, methodName, Encoding.UTF8.GetBytes(payload), qualityOfServiceLevel);
-            _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)
@@ -42,12 +34,7 @@ namespace MQTTnet.Extensions.Rpc
                 throw new ArgumentException("The method name cannot contain /, + or #.");
             }
 
-            if (!_isEnabled)
+            var requestTopic = $"MQTTnet.RPC/{Guid.NewGuid():N}/{methodName}";
-            {
-                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()
@@ -64,18 +51,21 @@ namespace MQTTnet.Extensions.Rpc
                     throw new InvalidOperationException();
                 }
 
-                await _mqttClient.PublishAsync(requestMessage);
+                await _mqttClient.SubscribeAsync(responseTopic, qualityOfServiceLevel).ConfigureAwait(false);
+                await _mqttClient.PublishAsync(requestMessage).ConfigureAwait(false);
+
                 return await tcs.Task.TimeoutAfter(timeout);
             }
             finally
             {
                 _waitingCalls.TryRemove(responseTopic, out _);
+                await _mqttClient.UnsubscribeAsync(responseTopic).ConfigureAwait(false);
             }
         }
 
         private void OnApplicationMessageReceived(object sender, MqttApplicationMessageReceivedEventArgs eventArgs)
         {
-            if (!_waitingCalls.TryRemove(eventArgs.ApplicationMessage.Topic, out TaskCompletionSource<byte[]> tcs))
+            if (!_waitingCalls.TryRemove(eventArgs.ApplicationMessage.Topic, out var tcs))
             {
                 return;
             }

Extensions/MQTTnet.Extensions.Rpc/SampleCCode.c

@@ -1 +1,28 @@
-
+// If using the MQTT client PubSubClient it must be ensured  that the request topic for each method is subscribed like the following.
+_mqttClient.subscribe("MQTTnet.RPC/+/ping");
+_mqttClient.subscribe("MQTTnet.RPC/+/do_something");
+
+// It is not allowed to change the structure of the topic. Otherwise RPC will not work. So method names can be separated using
+// an _ or . but no +, # or /.. If it is required to distinguish between devices own rules can be defined like the following.
+_mqttClient.subscribe("MQTTnet.RPC/+/deviceA.ping");
+_mqttClient.subscribe("MQTTnet.RPC/+/deviceB.ping");
+_mqttClient.subscribe("MQTTnet.RPC/+/deviceC.getTemperature");
+
+// Within the callback of the mqtt client the topic must be checked if it belongs to MQTTnet RPC. The following code shows one
+// possible way.
+void mqtt_Callback(char *topic, byte *payload, unsigned int payloadLength)
+{
+	String topicString = String(topic);
+
+	if (topicString.startsWith("MQTTnet.RPC/")) {
+		String responseTopic = topicString + String("/response");
+
+		if (topicString.endsWith("/deviceA.ping")) {
+			mqtt_publish(responseTopic, "pong", false);
+			return;
+		}
+	}
+}
+
+// Do not send response message with the _retain_ flag set to true.
+// All required data for a RPC call and the result must be placed into the payload.

Frameworks/MQTTnet.NetStandard/MqttApplicationMessageBuilder.cs

@@ -32,7 +32,12 @@ namespace MQTTnet
             return this;
         }
 
-        public MqttApplicationMessageBuilder WithPayload(MemoryStream payload)
+        public MqttApplicationMessageBuilder WithPayload(Stream payload)
+        {
+            return WithPayload(payload, payload.Length - payload.Position);
+        }
+
+        public MqttApplicationMessageBuilder WithPayload(Stream payload, long length)
         {
             if (payload == null)
             {
@@ -46,7 +51,7 @@ namespace MQTTnet
             }
             else
             {
-                _payload = new byte[payload.Length - payload.Position];
+                _payload = new byte[length];
                 payload.Read(_payload, 0, _payload.Length);
             }
 

Frameworks/MQTTnet.NetStandard/Packets/MqttUnsubscribe.cs

@@ -11,7 +11,7 @@ namespace MQTTnet.Packets
         public override string ToString()
         {
             var topicFiltersText = string.Join(",", TopicFilters);
-            return "Subscribe: [PacketIdentifier=" + PacketIdentifier + "] [TopicFilters=" + topicFiltersText + "]";
+            return "Unsubscribe: [PacketIdentifier=" + PacketIdentifier + "] [TopicFilters=" + topicFiltersText + "]";
         }
     }
 }

MQTTnet.sln

@@ -18,6 +18,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Build", "Build", "{67C28AC1
 		appveyor.yml = appveyor.yml
 		Build\build.ps1 = Build\build.ps1
 		Build\MQTTnet.AspNetCore.nuspec = Build\MQTTnet.AspNetCore.nuspec
+		Build\MQTTnet.Extensions.Rpc.nuspec = Build\MQTTnet.Extensions.Rpc.nuspec
 		Build\MQTTnet.nuspec = Build\MQTTnet.nuspec
 	EndProjectSection
 EndProject

Tests/MQTTnet.TestApp.UniversalWindows/MainPage.xaml.cs

@@ -350,13 +350,10 @@ namespace MQTTnet.TestApp.UniversalWindows
                 payload = Convert.FromBase64String(RpcPayload.Text);
             }
 
-            
             try
             {
                 var rpcClient = new MqttRpcClient(_mqttClient);
-                await rpcClient.EnableAsync();
                 var response = await rpcClient.ExecuteAsync(TimeSpan.FromSeconds(5), RpcMethod.Text, payload, qos);
-                await rpcClient.DisableAsync();
                 
                 RpcResponses.Items.Add(RpcMethod.Text + " >>> " + Encoding.UTF8.GetString(response));
             }