NTDLS / NTDLS.MemQueue

In memory non-persistent message queue with messaging and query/reply support for inter-process-communication, queuing, load-balancing and buffering.

NTDLS.MemQueue

📦 Be sure to check out the (replacement) NuGet pacakge: https://www.nuget.org/packages/NTDLS.MemoryQueue

❗ MemQueue has been rewritten and greatly simplified for stability, durability, performance, ease of use and maintainability. You can find the replacement at https://github.com/NTDLS/NTDLS.MemoryQueue.

🗃️ While we could have continued with this project, we ultimately decided to move to a new project because the framework is vastly different and we wanted to preserve the lower-level work that had been done here.

In memory non-persistent message queue with notifications/messages, query/reply support and several message broadcast schemes. Intended for inter-process-communication, queuing, load-balancing and buffering over TCP/IP.

Running the server:

Running the server is literally two lines of code and can be run in the same process as the client. The server does not have to be dedicated either, it can eimply be one of the process that is involved in inner-process-communication.

using MemQueue;

internal class Program
{
    static void Main()
    {
        var server = new NMQServer()
        {
            //There are lots of options if you want to get fancy.
        };

        server.Start(); //Start the server on the default port.
    }
}

Enqueuing a notification. A message type which does not expect a reply.

Enqueuing a notification (as we call them) is a one way message that is broadcast to all connected peer that have subscribed to the queue.

using MemQueue;
using System;

internal class Program
{
    static void Main()
    {
        var client = new NMQClient();

        client.Connect("localhost");

        var message = new NMQNotification("TestQueue", "TestLabel", $"This is a message sent at {DateTime.Now:u}!");
        client.Enqueue(message);
    }
}

Receiving a notification message:

Receiving a notification is easy. If you are subscribed to the queue, you will receive the message. Further messages will be held until the event method returns.

using MemQueue;
using System;

internal class Program
{
    static void Main()
    {
        var client = new NMQClient();

        client.OnNotificationReceived += Client_OnNotificationReceived; //Setup the event handler
        client.Connect("localhost"); //Connect to the server on the default port.
        client.Subscribe("TestQueue"); //We have to subscribe to a queue, otherwise we wont receive anything.
    }

    private static void Client_OnNotificationReceived(NMQClient sender, NMQNotification notification)
    {
        Console.WriteLine($"Message received: {notification.Message}");
    }
}

Enqueuing a query, a message type that does expect a reply:

You can also enque a query. The query will be received by a connected peer that is subscribed to the queue, respond to the query and you will receive the reply in code.

using MemQueue;
using System;
using System.Threading.Tasks;

internal class Program
{
    static void Main()
    {
        var client = new NMQClient();

        client.Connect("localhost"); //Connect to the server on the default port.
        client.Subscribe("TestQueue"); //We have to subscribe to a queue, otherwise we wont receive anything.

        var query = new NMQQuery("TestQueue", "Ping");

        //Enqueue a query and wait for the reply.
        client.QueryAsync(query).ContinueWith((t) =>
        {
            if (t.Status == TaskStatus.RanToCompletion && t.Result != null)
            {
                Console.WriteLine($"Received message: {t.Result.Message}.");
            }
        });
    }
}

Receiving a query and replying to it:

Receiving a query and responding to it is easy. The server handles all the routing.

using MemQueue;
using System;

internal class Program
{
    static void Main()
    {
        var client = new NMQClient();

        client.OnQueryReceived += Client_OnQueryReceived; //Setup the event handler.
        client.Connect("localhost"); //Connect to the server on the default port.
        client.Subscribe("TestQueue"); //We have to subscribe to a queue, otherwise we wont receive anything.
    }

    private static NMQQueryReplyResult Client_OnQueryReceived(NMQClient sender, NMQQuery query)
    {
        if (query.Message == "Ping") //We receive a query with the message "Ping", reply with "Pong".
        {
            return sender.Reply(query, new NMQReply("Pong"));
        }
        else
        {
            throw new NotImplementedException();
        }
    }
}

License

Apache-2.0