first commit

NitroxServer-Subnautica/Communication/IpcHost.cs

@@ -0,0 +1,102 @@
+using System;
+using System.IO;
+using System.IO.Pipes;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using NitroxModel.Helper;
+
+namespace NitroxServer_Subnautica.Communication;
+
+/// <summary>
+///     Exposes an IPC channel for other local processes to communicate with the server.
+/// </summary>
+public class IpcHost : IDisposable
+{
+    private readonly CancellationTokenSource commandReadCancellation;
+    private readonly NamedPipeServerStream server = new($"Nitrox Server {NitroxEnvironment.CurrentProcessId}", PipeDirection.In, 1);
+
+    private IpcHost(CancellationTokenSource commandReadCancellation)
+    {
+        this.commandReadCancellation = commandReadCancellation;
+    }
+
+    public static IpcHost StartReadingCommands(Action<string> onCommandReceived, CancellationToken cancellationToken = default)
+    {
+        Log.Info("Starting IPC host for command input");
+        ArgumentNullException.ThrowIfNull(onCommandReceived);
+
+        IpcHost host = new(CancellationTokenSource.CreateLinkedTokenSource(cancellationToken));
+        Thread thread = new(async () =>
+        {
+            while (!cancellationToken.IsCancellationRequested)
+            {
+                try
+                {
+                    string command = await host.ReadStringAsync(cancellationToken);
+                    onCommandReceived(command);
+                }
+                catch (OperationCanceledException)
+                {
+                    // ignored
+                }
+            }
+        });
+        thread.IsBackground = true;
+        thread.Start();
+        return host;
+    }
+
+    public async Task<string> ReadStringAsync(CancellationToken cancellationToken = default)
+    {
+        if (!await WaitForConnection())
+        {
+            return "";
+        }
+
+        try
+        {
+            byte[] sizeBytes = new byte[4];
+            await server.ReadExactlyAsync(sizeBytes, cancellationToken);
+            byte[] stringBytes = new byte[BitConverter.ToUInt32(sizeBytes)];
+            await server.ReadExactlyAsync(stringBytes, cancellationToken);
+
+            return Encoding.UTF8.GetString(stringBytes);
+        }
+        catch (Exception)
+        {
+            return "";
+        }
+    }
+
+    public void Dispose()
+    {
+        commandReadCancellation?.Cancel();
+        server.Dispose();
+    }
+
+    private async Task<bool> WaitForConnection()
+    {
+        if (server.IsConnected)
+        {
+            return true;
+        }
+        try
+        {
+            await server.WaitForConnectionAsync();
+            return true;
+        }
+        catch (IOException)
+        {
+            try
+            {
+                server.Disconnect();
+            }
+            catch (Exception)
+            {
+                // ignored
+            }
+        }
+        return false;
+    }
+}