pvginkel / PipeRPC

Simple, fast, JSON based RPC protocol for communicating with external processes using anonymous named pipes.

PipeRpc

Apache License 2.0

Download from NuGet.

Introduction

PipeRpc is a library to simplify communication with external processes. It was designed as a simple replacement to AppDomain's.

Example

To setup PipeRpc, you need a server process and a client process. The server process is the process that starts the client application to communicate with.

A simple server implementation looks as follows:

// Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using PipeRpc;

namespace SampleServer
{
    public static class Program
    {
        public static void Main(string[] args)
        {
            using (var server = new PipeRpcServer())
            {
                // Start the server with the location and arguments to the RPC client.
                
                server.Start(new ClientStartInfo(
                    typeof(SampleClient.Program).Assembly.Location,
                    null,
                    server.Handle.ToString()
                ));

                // Invoke a method on the client service.

                int result = server.Invoke<int>("Add", 1, 2);

                // Write the results.

                Console.WriteLine($"1 + 2 = {result}");
            }
        }
    }
}

This hosts an RPC service and ensures that the RPC client is started automatically. The client looks as follows:

// Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using PipeRpc;

namespace SampleClient
{
    public static class Program
    {
        public static void Main(string[] args)
        {
            // Start the RPC client with the handle to the RPC server
            // and an instance of the service to host.

            using (var client = new PipeRpcClient(PipeRpcHandle.FromString(args[0]), new Service()))
            {
                client.Run();
            }
        }
    }
}

// Service.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SampleClient
{
    public class Service
    {
        public int Add(int a, int b)
        {
            return a + b;
        }
    }
}

The entry point of the RPC client starts an instance of the PipeRpcClient with the handle created by the server. The service itself is just an instance of a class with some public methods. PipeRpc will automatically find these methods and make them available to be called from the server.

Features

PipeRpc supports the following features:

• Calling methods with complex arguments. Newtonsoft.Json is used to serialize data between the RPC server and client, and supports a wide range of data types;
• Cancelling running request. If a CancellationToken is provided as an argument to Invoke, and the service takes a CancellationToken, cancellation request are automatically marshaled to the RPC client;
• Post back events. Events can be registered on an PipeRpcServer using the On method. If the service method takes an IOperationContext parameter, this can be used to post an event back. This can e.g. be used for progress reporting;
• Running the RPC client in process. During development, the RPC client can be run in process in an AppDomain by constructing the PipeRpcServer with the value PipeRpcServerMode.Local. This greatly simplifies debugging the RPC client.

Switching between local and remote mode can be done as follows:

#if DEBUG
var mode = PipeRpcServerMode.Local;
#else
var mode = PipeRpcServerMode.Remote;
#endif
using (var server = new PipeRpcServer(mode))
{
    // ...

Performance

PipeRpc is built to be fast. Below is a run of the benchmark suite part of the project, run on an Intel i7-7700HQ:

              Method |   Mode |      Mean |      Error |     StdDev |
-------------------- |------- |----------:|-----------:|-----------:|
 ReturnComplexObject |  Local |  53.83 us |  4.2649 us |  1.1078 us |
 ReturnComplexObject | Remote |  53.40 us |  2.4947 us |  0.6480 us |
        Cancellation |  Local |  50.21 us |  7.2700 us |  1.8884 us |
        Cancellation | Remote |  50.40 us |  2.0542 us |  0.5336 us |
           ReturnInt |  Local |  27.42 us |  0.9550 us |  0.2481 us |
           ReturnInt | Remote |  28.98 us |  1.7416 us |  0.4524 us |