Indigo is re-released into the wild

My team and product at Microsoft are code-named 'Indigo'. The last time we publicly revealed our work-in-progress product was at the 2003 PDC; as you might expect, there has been a lot of changes since then. Yesterday, we demonstrated our latest work at the VSLive conference, which means I can now talk about my particular area of ownership; I'm a tester of the 'queue channel' (or is it 'queued channel', I can never remember). This channel blends the power of MSMQ queued messaging with the usability and flexibility of the Indigo API.

I'll give an example; Mr. Vasters recently posted a simple 'Hello World' service that uses Indigo; I'll repeat his example below, then show how to convert it to a queued service - that is, the clients write messages into the queue, and the service reads them out:

namespace IndiHello
{
      [ServiceContract]
      public class Hello
      {
            [OperationContract]
            public string SayHello(string name)
            {
                  return "Hello " + name;
            }
      }
      class Program
      {
            static void Main(string[] args)
            {
                  ServiceHost<Hello> host = new ServiceHost<Hello>(new Uri("http://localhost/hello"));
                  host.AddEndpoint(typeof(Hello), new BasicProfileHttpBinding(), "ep");
                  host.Open();
                  Console.WriteLine("Press ENTER to quit");
                  Console.ReadLine();
                  host.Close();
            }
      }
}

Here's what it looks like as a queued service; I'll mark my changes in red:

using System;
using System.ServiceModel;

namespace IndiHello
{
      [ServiceContract]
      public class Hello
      {
            [OperationContract(IsOneWay = true)]
            public void SayHello(string name)
            {
                  Console.WriteLine("Hello " + name); // can't return anything - its one-way
}
            }
            class Program
            {
                  static void Main(string[] args)
                  {
                        ServiceHost<Hello> host = new ServiceHost<Hello>();
                        host.AddEndpoint(typeof(Hello), new NetMsmqBinding(), "net.msmq://localhost/Private$/hello/");
                        host.Open();
                        Console.WriteLine("Press ENTER to quit");
                        Console.ReadLine();
                        host.Close();
                  }
            }
      }
}

.
Pretty straightforward. Messages can only travel in one direction on a queued channel, so we make the appropriate changes for that. We adjust the binding to reflect the fact that we want to use MSMQ as our transport, not HTTP. Lastly, we change the address to use the net.msmq scheme and contain the address of an MSMQ queue that’s on the local machine.

One point I’ve glossed over – the queue that’s backing this channel needs to be created beforehand; Indigo does not create queues “under the covers”. Typically an admin would use the MSMQ MMC snap-in to create his queues; for my testing purposes, I use System.Messaging:

using System.Messaging;

string queueName = @”localhost\Private$\hello”;
if (!MessageQueue.Exists(queueName))
{
      MessageQueue queue = MessageQueue.Create(queueName, true);
      queue.Close();
}