From 59f89c10d3b19d2dff02b651d893181519a7f3e0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franti=C5=A1ek=20Boh=C3=A1=C4=8Dek?=
 <fandabohacek@gmail.com>
Date: Wed, 25 Jan 2023 16:21:50 +0100
Subject: [PATCH] feat: add named pipes implementation

---
 .../Extensions/ServiceCollectionExtensions.cs |  41 ++++++
 .../NamedPipeClient.cs                        |  64 +++++++++
 .../NamedPipeServer.cs                        | 125 ++++++++++++++++++
 .../NosSmooth.Comms.NamedPipes.csproj         |  13 ++
 4 files changed, 243 insertions(+)
 create mode 100644 src/Core/NosSmooth.Comms.NamedPipes/Extensions/ServiceCollectionExtensions.cs
 create mode 100644 src/Core/NosSmooth.Comms.NamedPipes/NamedPipeClient.cs
 create mode 100644 src/Core/NosSmooth.Comms.NamedPipes/NamedPipeServer.cs
 create mode 100644 src/Core/NosSmooth.Comms.NamedPipes/NosSmooth.Comms.NamedPipes.csproj

diff --git a/src/Core/NosSmooth.Comms.NamedPipes/Extensions/ServiceCollectionExtensions.cs b/src/Core/NosSmooth.Comms.NamedPipes/Extensions/ServiceCollectionExtensions.cs
new file mode 100644
index 0000000..f6a6b32
--- /dev/null
+++ b/src/Core/NosSmooth.Comms.NamedPipes/Extensions/ServiceCollectionExtensions.cs
@@ -0,0 +1,41 @@
+//
+//  ServiceCollectionExtensions.cs
+//
+//  Copyright (c) František Boháček. All rights reserved.
+//  Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.IO.Pipes;
+using Microsoft.Extensions.DependencyInjection;
+using NosSmooth.Comms.Data;
+
+namespace NosSmooth.Comms.NamedPipes.Extensions;
+
+/// <summary>
+/// Extension methods for <see cref="IServiceCollection"/>.
+/// </summary>
+public static class ServiceCollectionExtensions
+{
+    /// <summary>
+    /// Adds a named pipe client as a <see cref="IClient"/>.
+    /// </summary>
+    /// <param name="serviceCollection">The service collection.</param>
+    /// <param name="pipeNameResolver">A function for resolving the name of the pipe using service provider.</param>
+    /// <returns>The same service collection.</returns>
+    public static IServiceCollection AddNamedPipeClient
+        (this IServiceCollection serviceCollection, Func<IServiceProvider, string> pipeNameResolver)
+        => serviceCollection
+            .AddSingleton<NamedPipeClient>(p => new NamedPipeClient(pipeNameResolver(p)))
+            .AddSingleton<IClient>(p => p.GetRequiredService<NamedPipeClient>());
+
+    /// <summary>
+    /// Adds a named pipe server as a <see cref="IServer"/>.
+    /// </summary>
+    /// <param name="serviceCollection">The service collection.</param>
+    /// <param name="pipeNameResolver">A function for resolving the name of the pipe using service provider.</param>
+    /// <returns>The same service collection.</returns>
+    public static IServiceCollection AddNamedPipeServer
+        (this IServiceCollection serviceCollection, Func<IServiceProvider, string> pipeNameResolver)
+        => serviceCollection
+            .AddSingleton<NamedPipeServer>(p => new NamedPipeServer(pipeNameResolver(p)))
+            .AddSingleton<IServer>(p => p.GetRequiredService<NamedPipeServer>());
+}
\ No newline at end of file
diff --git a/src/Core/NosSmooth.Comms.NamedPipes/NamedPipeClient.cs b/src/Core/NosSmooth.Comms.NamedPipes/NamedPipeClient.cs
new file mode 100644
index 0000000..d806ddf
--- /dev/null
+++ b/src/Core/NosSmooth.Comms.NamedPipes/NamedPipeClient.cs
@@ -0,0 +1,64 @@
+//
+//  NamedPipeClient.cs
+//
+//  Copyright (c) František Boháček. All rights reserved.
+//  Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Data;
+using System.IO.Pipes;
+using NosSmooth.Comms.Data;
+using Remora.Results;
+
+namespace NosSmooth.Comms.NamedPipes;
+
+/// <summary>
+/// A client using named pipes.
+/// </summary>
+public class NamedPipeClient : IClient
+{
+    private readonly NamedPipeClientStream _stream;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="NamedPipeClient"/> class.
+    /// </summary>
+    /// <param name="pipeName">The name of the pipe.</param>
+    public NamedPipeClient(string pipeName)
+    {
+        _stream = new NamedPipeClientStream(".", pipeName, PipeDirection.InOut, PipeOptions.Asynchronous);
+    }
+
+    /// <inheritdoc />
+    public ConnectionState State => _stream.IsConnected ? ConnectionState.Open : ConnectionState.Closed;
+
+    /// <inheritdoc />
+    public Stream ReadStream => _stream;
+
+    /// <inheritdoc />
+    public Stream WriteStream => _stream;
+
+    /// <inheritdoc />
+    public void Disconnect()
+    {
+        _stream.Close();
+        _stream.Dispose();
+    }
+
+    /// <inheritdoc />
+    public async Task<Result> ConnectAsync(CancellationToken ct)
+    {
+        try
+        {
+            await _stream.ConnectAsync(ct);
+            return Result.FromSuccess();
+        }
+        catch (OperationCanceledException)
+        {
+            // ignored
+            return Result.FromSuccess();
+        }
+        catch (Exception e)
+        {
+            return e;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Core/NosSmooth.Comms.NamedPipes/NamedPipeServer.cs b/src/Core/NosSmooth.Comms.NamedPipes/NamedPipeServer.cs
new file mode 100644
index 0000000..ec07069
--- /dev/null
+++ b/src/Core/NosSmooth.Comms.NamedPipes/NamedPipeServer.cs
@@ -0,0 +1,125 @@
+//
+//  NamedPipeServer.cs
+//
+//  Copyright (c) František Boháček. All rights reserved.
+//  Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Data;
+using System.IO.Pipes;
+using NosSmooth.Comms.Data;
+using Remora.Results;
+
+namespace NosSmooth.Comms.NamedPipes;
+
+/// <summary>
+/// A server using named pipes.
+/// </summary>
+public class NamedPipeServer : IServer
+{
+    private readonly List<IConnection> _connections;
+    private readonly ReaderWriterLockSlim _readerWriterLock;
+    private readonly string _pipeName;
+    private bool _listening;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="NamedPipeServer"/> class.
+    /// </summary>
+    /// <param name="pipeName">The name of the pipe.</param>
+    public NamedPipeServer(string pipeName)
+    {
+        _readerWriterLock = new ReaderWriterLockSlim();
+        _pipeName = pipeName;
+        _connections = new List<IConnection>();
+    }
+
+    /// <inheritdoc />
+    public IReadOnlyList<IConnection> Clients
+    {
+        get
+        {
+            _readerWriterLock.EnterReadLock();
+            var connections = new List<IConnection>(_connections);
+            _readerWriterLock.ExitReadLock();
+            return connections.AsReadOnly();
+        }
+    }
+
+    /// <inheritdoc />
+    public async Task<Result<IConnection>> WaitForConnectionAsync(CancellationToken ct = default)
+    {
+        if (!_listening)
+        {
+            throw new InvalidOperationException("The server is not listening.");
+        }
+
+        var serverStream = new NamedPipeServerStream
+        (
+            _pipeName,
+            PipeDirection.InOut,
+            NamedPipeServerStream.MaxAllowedServerInstances,
+            PipeTransmissionMode.Byte,
+            PipeOptions.Asynchronous
+        );
+
+        await serverStream.WaitForConnectionAsync(ct);
+
+        var connection = new NamedPipeConnection(this, serverStream);
+        _readerWriterLock.EnterWriteLock();
+        _connections.Add(connection);
+        _readerWriterLock.ExitWriteLock();
+
+        return connection;
+    }
+
+    /// <inheritdoc />
+    public Task<Result> ListenAsync(CancellationToken stopToken = default)
+    {
+        _listening = true;
+        stopToken.Register(Close);
+        return Task.FromResult(Result.FromSuccess());
+    }
+
+    /// <inheritdoc />
+    public void Close()
+    {
+        _readerWriterLock.EnterReadLock();
+        var connections = new List<IConnection>(_connections);
+        _readerWriterLock.ExitReadLock();
+
+        foreach (var connection in connections)
+        {
+            connection.Disconnect();
+        }
+
+        _listening = false;
+    }
+
+    private class NamedPipeConnection : IConnection
+    {
+        private readonly NamedPipeServer _server;
+        private readonly NamedPipeServerStream _serverStream;
+
+        public NamedPipeConnection(NamedPipeServer server, NamedPipeServerStream serverStream)
+        {
+            _server = server;
+            _serverStream = serverStream;
+        }
+
+        public ConnectionState State { get; private set; } = ConnectionState.Open;
+
+        public Stream ReadStream => _serverStream;
+
+        public Stream WriteStream => _serverStream;
+
+        public void Disconnect()
+        {
+            _serverStream.Disconnect();
+            _serverStream.Close();
+            State = ConnectionState.Closed;
+
+            _server._readerWriterLock.EnterWriteLock();
+            _server._connections.Remove(this);
+            _server._readerWriterLock.ExitWriteLock();
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Core/NosSmooth.Comms.NamedPipes/NosSmooth.Comms.NamedPipes.csproj b/src/Core/NosSmooth.Comms.NamedPipes/NosSmooth.Comms.NamedPipes.csproj
new file mode 100644
index 0000000..62eb048
--- /dev/null
+++ b/src/Core/NosSmooth.Comms.NamedPipes/NosSmooth.Comms.NamedPipes.csproj
@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>net7.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\NosSmooth.Comms.Abstractions\NosSmooth.Comms.Abstractions.csproj" />
+    </ItemGroup>
+
+</Project>
-- 
2.48.1