Refactor sub/unsub management in managed client.

Build/MQTTnet.AspNetCore.nuspec

@@ -12,7 +12,7 @@
     <requireLicenseAcceptance>true</requireLicenseAcceptance>
     <description>This is a support library to integrate MQTTnet into AspNetCore.</description>
     <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2020</copyright>
+    <copyright>Copyright Christian Kratky 2016-2021</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 Blazor</tags>
     <dependencies>
       <group targetFramework="netstandard2.0">

Build/MQTTnet.Extensions.ManagedClient.nuspec

@@ -12,7 +12,7 @@
     <requireLicenseAcceptance>true</requireLicenseAcceptance>
     <description>This is an extension library which provides a managed MQTT client with additional features using MQTTnet.</description>
     <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2020</copyright>
+    <copyright>Copyright Christian Kratky 2016-2021</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 Blazor</tags>
     <dependencies>
       <dependency id="MQTTnet" version="$nugetVersion" />

Build/MQTTnet.Extensions.Rpc.nuspec

@@ -12,7 +12,7 @@
     <requireLicenseAcceptance>true</requireLicenseAcceptance>
     <description>This is an extension library which allows executing synchronous device calls including a response using MQTTnet.</description>
     <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2020</copyright>
+    <copyright>Copyright Christian Kratky 2016-2021</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 Blazor</tags>
     <dependencies>
       <dependency id="MQTTnet" version="$nugetVersion" />

Build/MQTTnet.Extensions.WebSocket4Net.nuspec

@@ -12,7 +12,7 @@
     <requireLicenseAcceptance>true</requireLicenseAcceptance>
     <description>This is an extension library which allows using _WebSocket4Net_ as transport for MQTTnet clients.</description>
     <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2020</copyright>
+    <copyright>Copyright Christian Kratky 2016-2021</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 Blazor</tags>
     <dependencies>
       <dependency id="MQTTnet" version="$nugetVersion" />

Build/MQTTnet.nuspec

@@ -12,7 +12,8 @@
     <requireLicenseAcceptance>true</requireLicenseAcceptance>
     <description>MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker) and supports v3.1.0, v3.1.1 and v5.0.0 of the MQTT protocol.</description>
     <releaseNotes>
-* [ManagedClient] Extended ReconnectAsync (thanks to @nvsnkv, #1202). 
+* [ManagedClient] Extended ReconnectAsync (thanks to @nvsnkv, #1202).
+* [ManagedClient] Improved Amazon AWS support (thanks to @scottbrogden-iheartmedia, #1209).
 * [Server] Fixed a memory/performance leak when using QoS Level 1.
 * [Server] Exposed connection timestamp in client status. 
 * [Server] Refactored connection management code. 
@@ -21,7 +22,7 @@
 * [MQTTnet, MQTTnet.Extensions.ManagedClient] Fixed bug that allowed invalid subscriptions (Thanks to @marcelwinh).
 Git commit: $gitCommit
     </releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2020</copyright>
+    <copyright>Copyright Christian Kratky 2016-2021</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 Blazor</tags>
     <dependencies>
       <group targetFramework="net452" />

Source/MQTTnet.Extensions.ManagedClient/IManagedMqttClientOptions.cs

@@ -18,6 +18,10 @@ namespace MQTTnet.Extensions.ManagedClient
 
         MqttPendingMessagesOverflowStrategy PendingMessagesOverflowStrategy { get; }
 
-        int? MaxSubcribeUnsubscribeMessagesAtOnce { get; }
+        /// <summary>
+        /// Defines the maximum amount of topic filters which will be sent in a SUBSCRIBE/UNSUBSCRIBE packet.
+        /// Amazon AWS limits this number to 8. The default is int.MaxValue.
+        /// </summary>
+        int MaxTopicFiltersInSubscribeUnsubscribePackets { get; }
     }
 }

Source/MQTTnet.Extensions.ManagedClient/ManagedMqttClient.cs

@@ -28,6 +28,7 @@ namespace MQTTnet.Extensions.ManagedClient
         ///  at reconnect and are solely owned by <see cref="MaintainConnectionAsync"/>.
         /// </summary>
         readonly Dictionary<string, MqttQualityOfServiceLevel> _reconnectSubscriptions = new Dictionary<string, MqttQualityOfServiceLevel>();
+
         readonly Dictionary<string, MqttQualityOfServiceLevel> _subscriptions = new Dictionary<string, MqttQualityOfServiceLevel>();
         readonly HashSet<string> _unsubscriptions = new HashSet<string>();
         readonly SemaphoreSlim _subscriptionsQueuedSignal = new SemaphoreSlim(0);
@@ -205,7 +206,6 @@ namespace MQTTnet.Extensions.ManagedClient
                         await applicationMessageSkippedHandler.HandleApplicationMessageSkippedAsync(applicationMessageSkippedEventArgs).ConfigureAwait(false);
                     }
                 }
-
             }
         }
 
@@ -248,6 +248,7 @@ namespace MQTTnet.Extensions.ManagedClient
                     _unsubscriptions.Add(topic);
                 }
             }
+
             _subscriptionsQueuedSignal.Release();
 
             return Task.FromResult(0);
@@ -481,8 +482,14 @@ namespace MQTTnet.Extensions.ManagedClient
 
                 lock (_subscriptions)
                 {
-                    subscriptions = _subscriptions.Select(i => new MqttTopicFilter { Topic = i.Key, QualityOfServiceLevel = i.Value }).ToList();
+                    subscriptions = _subscriptions.Select(i => new MqttTopicFilter
+                    {
+                        Topic = i.Key, 
+                        QualityOfServiceLevel = i.Value
+                    }).ToList();
+                    
                     _subscriptions.Clear();
+                    
                     unsubscriptions = new HashSet<string>(_unsubscriptions);
                     _unsubscriptions.Clear();
                 }
@@ -492,7 +499,7 @@ namespace MQTTnet.Extensions.ManagedClient
                     continue;
                 }
 
-                _logger.Verbose("Publishing {0} subscriptions and {1} unsubscriptions)", subscriptions.Count, unsubscriptions.Count);
+                _logger.Verbose("Publishing {0} added and {1} removed subscriptions", subscriptions.Count, unsubscriptions.Count);
 
                 foreach (var unsubscription in unsubscriptions)
                 {
@@ -504,48 +511,48 @@ namespace MQTTnet.Extensions.ManagedClient
                     _reconnectSubscriptions[subscription.Topic] = subscription.QualityOfServiceLevel;
                 }
 
-                List<MqttTopicFilter> subs = new List<MqttTopicFilter>();
-                foreach (var sub in subscriptions)
+                var addedTopicFilters = new List<MqttTopicFilter>();
+                foreach (var subscription in subscriptions)
                 {
-                    subs.Add(sub);
-                    //aws only allows 8 in a single message
-                    if (subs.Count == Options.MaxSubcribeUnsubscribeMessagesAtOnce)
+                    addedTopicFilters.Add(subscription);
+                    
+                    if (addedTopicFilters.Count == Options.MaxTopicFiltersInSubscribeUnsubscribePackets)
                     {
-                        await SendSubscribeUnsubscribe(subs, null).ConfigureAwait(false);
-                        subs.Clear();
+                        await SendSubscribeUnsubscribe(addedTopicFilters, null).ConfigureAwait(false);
+                        addedTopicFilters.Clear();
                     }
                 }
 
-                await SendSubscribeUnsubscribe(subs, null);
+                await SendSubscribeUnsubscribe(addedTopicFilters, null).ConfigureAwait(false);
 
-                List<string> unSubs = new List<string>();
+                var removedTopicFilters = new List<string>();
                 foreach (var unSub in unsubscriptions)
                 {
-                    unSubs.Add(unSub);
-                    //aws only allows 8 in a single message
-                    if (unSubs.Count == Options.MaxSubcribeUnsubscribeMessagesAtOnce)
+                    removedTopicFilters.Add(unSub);
+                    
+                    if (removedTopicFilters.Count == Options.MaxTopicFiltersInSubscribeUnsubscribePackets)
                     {
-                        await SendSubscribeUnsubscribe(null, unSubs).ConfigureAwait(false);
-                        unSubs.Clear();
+                        await SendSubscribeUnsubscribe(null, removedTopicFilters).ConfigureAwait(false);
+                        removedTopicFilters.Clear();
                     }
                 }
 
-                await SendSubscribeUnsubscribe(null, unSubs);
+                await SendSubscribeUnsubscribe(null, removedTopicFilters).ConfigureAwait(false);
             }
         }
 
-        async Task SendSubscribeUnsubscribe(List<MqttTopicFilter> subscriptions, List<string> unsubscriptions)
+        async Task SendSubscribeUnsubscribe(List<MqttTopicFilter> addedSubscriptions, List<string> removedSubscriptions)
         {
             try
             {
-                if (unsubscriptions != null && unsubscriptions.Any())
+                if (removedSubscriptions != null && removedSubscriptions.Any())
                 {
-                    await InternalClient.UnsubscribeAsync(unsubscriptions.ToArray()).ConfigureAwait(false);
+                    await InternalClient.UnsubscribeAsync(removedSubscriptions.ToArray()).ConfigureAwait(false);
                 }
 
-                if (subscriptions != null && subscriptions.Any())
+                if (addedSubscriptions != null && addedSubscriptions.Any())
                 {
-                    await InternalClient.SubscribeAsync(subscriptions.ToArray()).ConfigureAwait(false);
+                    await InternalClient.SubscribeAsync(addedSubscriptions.ToArray()).ConfigureAwait(false);
                 }
             }
             catch (Exception exception)
@@ -562,20 +569,26 @@ namespace MQTTnet.Extensions.ManagedClient
             {
                 if (_reconnectSubscriptions.Any())
                 {
-                    var subscriptions = _reconnectSubscriptions.Select(i => new MqttTopicFilter { Topic = i.Key, QualityOfServiceLevel = i.Value });
-                    List<MqttTopicFilter> subs = new List<MqttTopicFilter>();
+                    var subscriptions = _reconnectSubscriptions.Select(i => new MqttTopicFilter
+                    {
+                        Topic = i.Key, 
+                        QualityOfServiceLevel = i.Value
+                    });
+                    
+                    var topicFilters = new List<MqttTopicFilter>();
+                    
                     foreach (var sub in subscriptions)
                     {
-                        subs.Add(sub);
-                        //aws only allows 8 in a single message
-                        if (subs.Count == Options.MaxSubcribeUnsubscribeMessagesAtOnce)
+                        topicFilters.Add(sub);
+                        
+                        if (topicFilters.Count == Options.MaxTopicFiltersInSubscribeUnsubscribePackets)
                         {
-                            await SendSubscribeUnsubscribe(subs, null).ConfigureAwait(false);
-                            subs.Clear();
+                            await SendSubscribeUnsubscribe(topicFilters, null).ConfigureAwait(false);
+                            topicFilters.Clear();
                         }
                     }
 
-                    await SendSubscribeUnsubscribe(subs, null).ConfigureAwait(false);
+                    await SendSubscribeUnsubscribe(topicFilters, null).ConfigureAwait(false);
                 }
             }
             catch (Exception exception)
@@ -665,4 +678,4 @@ namespace MQTTnet.Extensions.ManagedClient
             return remainingTime < TimeSpan.Zero ? TimeSpan.Zero : remainingTime;
         }
     }
-}
+}

Source/MQTTnet.Extensions.ManagedClient/ManagedMqttClientOptions.cs

@@ -4,7 +4,7 @@ using MQTTnet.Server;
 
 namespace MQTTnet.Extensions.ManagedClient
 {
-    public class ManagedMqttClientOptions : IManagedMqttClientOptions
+    public sealed class ManagedMqttClientOptions : IManagedMqttClientOptions
     {
         public IMqttClientOptions ClientOptions { get; set; }
 
@@ -18,6 +18,6 @@ namespace MQTTnet.Extensions.ManagedClient
 
         public MqttPendingMessagesOverflowStrategy PendingMessagesOverflowStrategy { get; set; } = MqttPendingMessagesOverflowStrategy.DropNewMessage;
 
-        public int? MaxSubcribeUnsubscribeMessagesAtOnce { get; set; } = null;
+        public int MaxTopicFiltersInSubscribeUnsubscribePackets { get; set; } = int.MaxValue;
     }
 }

Source/MQTTnet.Extensions.ManagedClient/ManagedMqttClientOptionsBuilder.cs

@@ -69,9 +69,9 @@ namespace MQTTnet.Extensions.ManagedClient
             return this;
         }
 
-        public ManagedMqttClientOptionsBuilder WithMaxSubcribeUnsubscribeMessagesAtOnce(int? value)
+        public ManagedMqttClientOptionsBuilder WithMaxTopicFiltersInSubscribeUnsubscribePackets(int value)
         {
-            _options.MaxSubcribeUnsubscribeMessagesAtOnce = value;
+            _options.MaxTopicFiltersInSubscribeUnsubscribePackets = value;
             return this;
         }