Stride.Networking.Simple

This is a small lib which I wrote because it came to my mind and bugged me for the whole day.

Basically you want to do a simple connection client-server, but don't care for all that pesky networking stuff. Well, you're in luck - slap that lib onto your project and do the following:

Client

First add the NetworkClientSystem to your game - if you want to connect to the server straight away I have an extension for you:

using (var game = new Game())
{
    // Instantiate a connection to the server
    game.AddNetworkClient(out var networkClient);
    networkClient.Open("localhost", 25565);

    game.Run();
}

If you want to add it later (after game systems have been initialized), you need to call Open before adding it to the game systems collection.

var networkClient = new NetworkClientSystem(game.Services);
networkClient.Open("localhost", 25565);

game.Services.AddService(networkClient);
game.GameSystems.Add(networkClient);

Ok, that's it for connections, now let's write some scripts. The general idea is:

• We define a request for a handler using an enum
• Client has a custom script which extends NetworkScript
• Server has a custom script which extends NetworkScript
• We registered server script with the request
• Client runs first and sends the request
• They both then use Send/Receive methods to communicate
• Both scripts will use the Guid ScriptId to identify that they are supposed to talk to each other

/// Enum used to link <see cref="PingScript"/> and <see cref="PongScript"/>.
/// Put it in a project shared between client and server.
public enum PingRequest
{
    Start
}

public class PingScript : NetworkScript
{
    protected override async Task Execute()
    {
        // This will tell the server to instantiate a new PongScript
        await StartNewServerHandler(PingRequest.Start);

        while (!IsCancelled)
        {
            await Send("Ping");
            var response = await Receive<string>();
            Log.Info("Sent Ping; Received " + response);
            await Task.Delay(TimeSpan.FromSeconds(1));
        }
    }
}

Server

Right now the idea is to just have a standalone server - not sure how it would look if there was a fully headless Stride (which right now is not).

Running the server is pretty straight forward:

var services = new ServiceRegistry();
services.AddNetworkServer(out var networkServer)
    .AddNetworkHandler(PingRequest.Start, (srv, conn) => new PongScript(srv, conn));

await networkServer.OpenAsync(25565);
Console.WriteLine("Server started. Press any key to stop...");
Console.ReadKey();

Notice how we used the PingRequest enum to register the PongScript factory. And then for the script:

// Server script - needs to have the constructor with those two parameters to correctly use it
public class PongScript : NetworkScript
{
    public PongScript(IServiceRegistry serviceRegistry, NetworkConnection connection)
        : base(serviceRegistry, connection)
    {
    }

    protected override async Task Execute()
    {
        while (!IsCancelled)
        {
            var response = await Receive<string>();
            await Send("Pong");
            Log.Info($"Received {response}; Sent Pong");
        }
    }
}

There's a second example script in the repo.

Enjoy!

Custom serialization

I used the default Stride binary serialization for sending messages across the network - it's very efficient. If you're gonna use it remember about putting [DataContract] on your message classes. Also the server and client must have the same version of the class, because it's definition is hashed and that's how serialization system figures out the type of the serialized object.

You can write your own serialization provider if you wish. Just implement Stride.Networking.Simple.Serialization.INetworkSerializationProvider and add it to the services collection before the first network script is invoked.