Add low level client.

Source/MQTTnet/Diagnostics/IMqttNetChildLogger.cs

@@ -1,17 +0,0 @@
-using System;
-
-namespace MQTTnet.Diagnostics
-{
-    public interface IMqttNetChildLogger
-    {
-        IMqttNetChildLogger CreateChildLogger(string source = null);
-
-        void Verbose(string message, params object[] parameters);
-
-        void Info(string message, params object[] parameters);
-
-        void Warning(Exception exception, string message, params object[] parameters);
-
-        void Error(Exception exception, string message, params object[] parameters);
-    }
-}

Source/MQTTnet/Diagnostics/IMqttNetLogger.cs

@@ -6,8 +6,8 @@ namespace MQTTnet.Diagnostics
     {
         event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
 
-        IMqttNetChildLogger CreateChildLogger(string source = null);
+        IMqttNetLogger CreateChildLogger(string source = null);
 
-        void Publish(MqttNetLogLevel logLevel, string source, string message, object[] parameters, Exception exception);
+        void Publish(MqttNetLogLevel logLevel, string message, object[] parameters, Exception exception);
     }
 }

Source/MQTTnet/Diagnostics/MqttNetChildLogger.cs

@@ -1,51 +0,0 @@
-using System;
-
-namespace MQTTnet.Diagnostics
-{
-    public class MqttNetChildLogger : IMqttNetChildLogger
-    {
-        private readonly IMqttNetLogger _logger;
-        private readonly string _source;
-
-        public MqttNetChildLogger(IMqttNetLogger logger, string source)
-        {
-            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
-            _source = source;
-        }
-
-        public IMqttNetChildLogger CreateChildLogger(string source)
-        {
-            string childSource;
-            if (!string.IsNullOrEmpty(_source))
-            {
-                childSource = _source + "." + source;
-            }
-            else
-            {
-                childSource = source;
-            }
-
-            return new MqttNetChildLogger(_logger, childSource);
-        }
-
-        public void Verbose(string message, params object[] parameters)
-        {
-            _logger.Publish(MqttNetLogLevel.Verbose, _source, message, parameters, null);
-        }
-
-        public void Info(string message, params object[] parameters)
-        {
-            _logger.Publish(MqttNetLogLevel.Info, _source, message, parameters, null);
-        }
-
-        public void Warning(Exception exception, string message, params object[] parameters)
-        {
-            _logger.Publish(MqttNetLogLevel.Warning, _source, message, parameters, exception);
-        }
-
-        public void Error(Exception exception, string message, params object[] parameters)
-        {
-            _logger.Publish(MqttNetLogLevel.Error, _source, message, parameters, exception);
-        }
-    }
-}

Source/MQTTnet/Diagnostics/MqttNetLogMessagePublishedEventArgs.cs

@@ -7,8 +7,12 @@ namespace MQTTnet.Diagnostics
         public MqttNetLogMessagePublishedEventArgs(MqttNetLogMessage logMessage)
         {
             TraceMessage = logMessage ?? throw new ArgumentNullException(nameof(logMessage));
+            LogMessage = logMessage ?? throw new ArgumentNullException(nameof(logMessage));
         }
 
+        [Obsolete("Use new proeprty LogMessage instead.")]
         public MqttNetLogMessage TraceMessage { get; }
+
+        public MqttNetLogMessage LogMessage { get; }
     }
 }

Source/MQTTnet/Diagnostics/MqttNetLogger.cs

@@ -4,21 +4,27 @@ namespace MQTTnet.Diagnostics
 {
     public class MqttNetLogger : IMqttNetLogger
     {
-        private readonly string _logId;
+        readonly string _logId;
+        readonly string _source;
 
-        public MqttNetLogger(string logId = null)
+        public MqttNetLogger(string source, string logId = null)
         {
+            _source = source;
             _logId = logId;
         }
 
+        public MqttNetLogger()
+        {
+        }
+
         public event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
 
-        public IMqttNetChildLogger CreateChildLogger(string source = null)
+        public IMqttNetLogger CreateChildLogger(string source = null)
         {
-            return new MqttNetChildLogger(this, source);
+            return new MqttNetLogger(source, _logId);
         }
 
-        public void Publish(MqttNetLogLevel logLevel, string source, string message, object[] parameters, Exception exception)
+        public void Publish(MqttNetLogLevel logLevel, string message, object[] parameters, Exception exception)
         {
             var hasLocalListeners = LogMessagePublished != null;
             var hasGlobalListeners = MqttNetGlobalLogger.HasListeners;
@@ -40,7 +46,7 @@ namespace MQTTnet.Diagnostics
                 }
             }
 
-            var traceMessage = new MqttNetLogMessage(_logId, DateTime.UtcNow, Environment.CurrentManagedThreadId, source, logLevel, message, exception);
+            var traceMessage = new MqttNetLogMessage(_logId, DateTime.UtcNow, Environment.CurrentManagedThreadId, _source, logLevel, message, exception);
 
             if (hasGlobalListeners)
             {

Source/MQTTnet/Diagnostics/MqttNetLoggerExtensions.cs

@@ -0,0 +1,35 @@
+using System;
+
+namespace MQTTnet.Diagnostics
+{
+    public static class MqttNetLoggerExtensions
+    {
+        public static void Verbose(this IMqttNetLogger logger, string message, params object[] parameters)
+        {
+            if (logger is null) throw new ArgumentNullException(nameof(logger));
+
+            logger.Publish(MqttNetLogLevel.Verbose, message, parameters, null);
+        }
+
+        public static void Info(this IMqttNetLogger logger, string message, params object[] parameters)
+        {
+            if (logger is null) throw new ArgumentNullException(nameof(logger));
+
+            logger.Publish(MqttNetLogLevel.Info, message, parameters, null);
+        }
+
+        public static void Warning(this IMqttNetLogger logger, Exception exception, string message, params object[] parameters)
+        {
+            if (logger is null) throw new ArgumentNullException(nameof(logger));
+
+            logger.Publish(MqttNetLogLevel.Warning, message, parameters, exception);
+        }
+
+        public static void Error(this IMqttNetLogger logger, Exception exception, string message, params object[] parameters)
+        {
+            if (logger is null) throw new ArgumentNullException(nameof(logger));
+
+            logger.Publish(MqttNetLogLevel.Error, message, parameters, exception);
+        }
+    }
+}

Source/MQTTnet/Diagnostics/TargetFrameworkProvider.cs

@@ -1,6 +1,6 @@
 namespace MQTTnet.Diagnostics
 {
-    public static class TargetFrameworkInfoProvider
+    public static class TargetFrameworkProvider
     {
         public static string TargetFramework
         {