feat: Add logging to the TCP and USB connection.

ScpiNet/TcpScpiConnection.cs

@@ -2,6 +2,7 @@
 using System.Net.Sockets;
 using System.Threading.Tasks;
 using System.Threading;
+using Microsoft.Extensions.Logging;
 
 namespace ScpiNet
 {
@@ -35,17 +36,29 @@ public class TcpScpiConnection : IScpiConnection
 		/// </summary>
 		public int Port { get; }
 
+		/// <summary>
+		/// Default response timeout in milliseconds.
+		/// </summary>
+		public const int DefaultTimeout = 250;
+
+		/// <summary>
+		/// Logger instance.
+		/// </summary>
+		protected ILogger<TcpScpiConnection> Logger { get; }
+
 		/// <summary>
 		/// Creates an instance of TcpScpiConnection.
 		/// </summary>
 		/// <param name="host">DNS name or IP address of the SCPI device.</param>
 		/// <param name="port">Target TCP port of the connected SCPI device.</param>
 		/// <param name="timeout">Read/write operation timeout in milliseconds.</param>
-		public TcpScpiConnection(string host, int port, int timeout = 250)
+		/// <param name="logger">Instance of a logger abstraction.</param>
+		public TcpScpiConnection(string host, int port, int timeout = DefaultTimeout, ILogger<TcpScpiConnection> logger = null)
 		{
 			Host = host;
 			Port = port;
 			Timeout = timeout;
+			Logger = logger;
 		}
 
 		/// <summary>
@@ -62,6 +75,7 @@ public async Task Open(CancellationToken cancellationToken = default)
 			};
 
 			// Start asynchronous connection and connection timeout task:
+			Logger?.LogInformation($"Creating TCP connection to {Host}:{Port}...", Host, Port);
 			Task timeoutTask = Task.Delay(100, cancellationToken);
 			Task connTask = _Client.ConnectAsync(Host, Port);
 
@@ -70,24 +84,29 @@ public async Task Open(CancellationToken cancellationToken = default)
 
 			// Check for cancelling:
 			if (timeoutTask.IsCanceled) {
+				Logger?.LogWarning("Connection to the remote device has been cancelled.");
 				_Client.Dispose();
 				_Client = null;
 				throw new OperationCanceledException();
 			}
 
 			// Check for timeout:
 			if (timeoutTask.IsCompleted) {
+				Logger?.LogError($"Connection to the remote device {Host}:{Port} timed out.");
 				_Client.Dispose();
 				_Client = null;
 				throw new TimeoutException($"Connection to the remote device {Host}:{Port} timed out.");
 			}
+
+			Logger?.LogInformation("Connection succeeded.");
 		}
 
 		/// <summary>
 		/// Closes active connection.
 		/// </summary>
 		public void Close()
 		{
+			Logger?.LogInformation("Closing the TCP connection.");
 			_Client?.Dispose();
 			_Client = null;
 		}
@@ -163,6 +182,7 @@ public async Task ClearBuffers(CancellationToken cancellationToken = default)
 				throw new InvalidOperationException("Cannot clear buffers, the connection is not open.");
 			}
 
+			Logger?.LogDebug("Clearing input buffer.");
 			NetworkStream stream = _Client.GetStream();
 			while (stream.DataAvailable) {
 				await stream.ReadAsync(buffer, 0, buffer.Length, cancellationToken);

ScpiNet/UsbScpiConnection.cs

@@ -1,4 +1,5 @@
-using Microsoft.Win32.SafeHandles;
+using Microsoft.Extensions.Logging;
+using Microsoft.Win32.SafeHandles;
 using System;
 using System.Collections.Generic;
 using System.Runtime.InteropServices;
@@ -365,6 +366,11 @@ private struct SP_DEVICE_INTERFACE_DETAIL_DATA
 		/// </summary>
 		public bool IsOpen => DevHandle?.IsInvalid == false && !DevHandle.IsClosed;
 
+		/// <summary>
+		/// Logger instance.
+		/// </summary>
+		protected ILogger<UsbScpiConnection> Logger { get; }
+
 		/// <summary>
 		/// Gets the list of connected USB devices.
 		/// </summary>
@@ -428,11 +434,13 @@ public static List<string> GetUsbDeviceList()
 		/// Creates an instance of UsbTmc device driver and opens the device..
 		/// </summary>
 		/// <param name="devPath">Device path to open.</param>
-		public UsbScpiConnection(string devPath)
+		/// <param name="logger">Instance of a logger abstraction.</param>
+		public UsbScpiConnection(string devPath, ILogger<UsbScpiConnection> logger = null)
 		{
 			DevicePath = devPath;
 			DevHandle = null;
 			Tag = 1;
+			Logger = logger;
 		}
 
 		/// <summary>
@@ -445,6 +453,7 @@ public Task Open(CancellationToken cancellationToken = default)
 			Close();
 
 			// Open the device for exclusive asynchronous access:
+			Logger?.LogInformation($"Opening USB TMC device '{DevicePath}'...");
 			DevHandle = CreateFile(
 				DevicePath,
 				EFileAccess.GenericRead | EFileAccess.GenericWrite,
@@ -466,6 +475,7 @@ public Task Open(CancellationToken cancellationToken = default)
 			// it breaks communication with Keysight multimeter.
 			//ResetPipe();
 
+			Logger?.LogInformation("USB TMC connection succeeded.");
 			return Task.CompletedTask;
 		}
 
@@ -474,8 +484,11 @@ public Task Open(CancellationToken cancellationToken = default)
 		/// </summary>
 		public void Close()
 		{
-			DevHandle?.Close();
-			DevHandle = null;
+			if (DevHandle != null) {
+				Logger?.LogInformation("Closing USB TMC device.");
+				DevHandle.Close();
+				DevHandle = null;
+			}
 		}
 
 		/// <summary>
@@ -490,6 +503,7 @@ public async Task ClearBuffers(CancellationToken cancellationToken = default)
 
 			// Read all data from the device until it is empty. The other way is to use the ResetPipe() method,
 			// but it does not work with all TMC devices.
+			Logger?.LogDebug("Clearing input buffer.");
 			ReadResult result;
 			byte[] buffer = new byte[1024];
 			do {
@@ -504,6 +518,7 @@ public void ResetPipe()
 		{
 			byte[] pipeType = new byte[4] { (byte)UsbTmcPipeType.AllPipes, 0, 0, 0 };
 
+			Logger?.LogDebug("Reset pipe.");
 			bool ret = DeviceIoControl(DevHandle, IoctlUsbTmc.ResetPipe, pipeType, pipeType.Length, IntPtr.Zero, 0, out int _, IntPtr.Zero);
 			if (!ret) {
 				throw new Exception(string.Format("ResetPipe() failed. Last error: {0}.", Marshal.GetLastWin32Error()));