Add server implementation

MQTTnet.Core/Diagnostics/MqttTrace.cs

@@ -0,0 +1,44 @@
+using System;
+
+namespace MQTTnet.Core.Diagnostics
+{
+    public static class MqttTrace
+    {
+        public static event EventHandler<MqttTraceMessagePublishedEventArgs> TraceMessagePublished;
+
+        public static void Verbose(string source, string message)
+        {
+            Publish(source, MqttTraceLevel.Verbose, null, message);
+        }
+
+        public static void Information(string source, string message)
+        {
+            Publish(source, MqttTraceLevel.Information, null, message);
+        }
+
+        public static void Warning(string source, string message)
+        {
+            Publish(source, MqttTraceLevel.Warning, null, message);
+        }
+
+        public static void Warning(string source, Exception exception, string message)
+        {
+            Publish(source, MqttTraceLevel.Warning, exception, message);
+        }
+
+        public static void Error(string source, string message)
+        {
+            Publish(source, MqttTraceLevel.Error, null, message);
+        }
+
+        public static void Error(string source, Exception exception, string message)
+        {
+            Publish(source, MqttTraceLevel.Error, exception, message);
+        }
+
+        private static void Publish(string source, MqttTraceLevel traceLevel, Exception exception, string message)
+        {
+            TraceMessagePublished?.Invoke(null, new MqttTraceMessagePublishedEventArgs(Environment.CurrentManagedThreadId, source, traceLevel, message, exception));
+        }
+    }
+}

MQTTnet.Core/Diagnostics/MqttTraceLevel.cs

@@ -0,0 +1,10 @@
+namespace MQTTnet.Core.Diagnostics
+{
+    public enum  MqttTraceLevel
+    {
+        Verbose,
+        Information,
+        Warning,
+        Error
+    }
+}

MQTTnet.Core/Diagnostics/MqttTraceMessagePublishedEventArgs.cs

@@ -0,0 +1,26 @@
+using System;
+
+namespace MQTTnet.Core.Diagnostics
+{
+    public class MqttTraceMessagePublishedEventArgs : EventArgs
+    {
+        public MqttTraceMessagePublishedEventArgs(int threadId, string source, MqttTraceLevel level, string message, Exception exception)
+        {
+            ThreadId = threadId;
+            Source = source;
+            Level = level;
+            Message = message;
+            Exception = exception;
+        }
+
+        public int ThreadId { get; }
+
+        public string Source { get; }
+
+        public MqttTraceLevel Level { get; }
+
+        public string Message { get; }
+
+        public Exception Exception { get; }
+    }
+}