Menees.Remoting 0.4.0-alpha

Remoting

This repo provides a simple RMI and IPC library for .NET Framework 4.8 and .NET 6.0+ applications. It's designed to help ease the migration from legacy WCF and .NET Remoting when porting code from .NET Framework to modern .NET. However, this library doesn't try to do all the things like WCF and .NET Remoting.

Menees.Remoting:

• Prefers simplicity over performance.
• Is designed for non-chatty communication.
• Can't pass or return a .NET reference directly.
• Requires values to be serialized going to and from the server.
• Uses named pipes and a serializer of your choice (default is System.Text.Json).
• Doesn't use or care about MarshalByRefObject, OperationContract, ServiceContract, etc.

RMI

Menees.Remoting provides RmiClient to invoke .NET interface methods in a remote RmiServer. The server process exposes a .NET interface for a given instance object. Then one or more client processes invoke .NET interface methods on the server's instance object. .NET's DispatchProxy.Create is used to generate the interface proxy, so clients can invoke the interface methods as normal C# calls.

[TestMethod]
public void HasherExample()
{
    const string ServerPath = "Menees.Remoting.RmiClientTests.HasherExample";

    using RmiServer<IHasher> server = new(new Hasher(), ServerPath);
    server.Start();

    using RmiClient<IHasher> client = new(ServerPath);
    IHasher proxy = client.CreateProxy();

    proxy.Hash(new byte[] { 1, 2, 3, 4 }).Length.ShouldBe(20);
    proxy.Hash("Testing").ShouldBe("0820b32b206b7352858e8903a838ed14319acdfd");
}

internal interface IHasher
{
    byte[] Hash(byte[] data);
    string Hash(string text);
}

internal class Hasher : IHasher
{
    public byte[] Hash(byte[] data)
    {
        using HashAlgorithm hasher = SHA1.Create();
        return hasher.ComputeHash(data);
    }

    public string Hash(string text)
    {
        byte[] hash = this.Hash(Encoding.UTF8.GetBytes(text));
        return string.Concat(hash.Select(b => $"{b:x2}"));
    }
}

For more usage examples see:

• RmiClientTests
• RmiServerTests

Due to the synchronous API of the underlying DispatchProxy.Invoke method, all the client invocations are sent synchronously to the server. The RmiClient can't do asynchronous calls to the RmiServer due to risks with sync over async. For more on DispatchProxy's lack of InvokeAsync support see #19349 and the comments for Migrating RealProxy Usage to DispatchProxy.

IPC

Menees.Remoting provides MessageClient to send a TIn-typed request message to a MessageServer and receive a TOut-typed response message. Message IPC only supports asynchronous calls, and the server requires a lambda that takes a TIn and returns a Task<TOut>.

[TestMethod]
public async Task Base64ExampleAsync()
{
    const string ServerPath = "Menees.Remoting.MessageNodeTests.Base64ExampleAsync";

    using MessageServer<byte[], string> server = new(data => Task.FromResult(Convert.ToBase64String(data)), ServerPath);
    server.Start();

    using MessageClient<byte[], string> client = new(ServerPath);
    string response = await client.SendAsync(new byte[] { 1, 2, 3, 4 }).ConfigureAwait(false);
    response.ShouldBe("AQIDBA==");
}

For more usage examples see:

• MessageNodeTests

No .NET Standard 2.0 Support

This library doesn't target .NET Standard 2.0 because that standard doesn't support:

• DispatchProxy.Create due to lack of Reflection.Emit support in .NET Standard 2.0.
• Named pipe security (see #26869 and StackOverflow).