Pushing data to the signalr clients.

DataController.cs

public class DataController : Controller
{
  private readonly IMachineState machineState;
  private readonly ISampleWriter sampleWriter;
  private readonly IHubContext<FeedHub> feedHub;

  public DataController(IMachineState machineState, ISampleWriter sampleWriter, IHubContext<FeedHub> feedHub)
  {
    this.machineState = machineState;
    this.sampleWriter = sampleWriter;
    this.feedHub = feedHub;
  }

  [HttpPost]
  public async Task<ActionResult> ProvideReading(uint milliseconds, double speed, int count)
  {
    // Update our machine state.
    machineState.UpdateMachineState(milliseconds, speed, count);

    // Write the sample to file (our sample writer) and update all clients
    // Wait for them both to finish.
    await Task.WhenAll(
      sampleWriter.ProvideSample(machineState.LastSample, machineState.Speed, machineState.Count),
      feedHub.Clients.All.SendAsync("newData", 
                                    machineState.LastSample.ToString("o"), 
                                    machineState.Speed, 
                                    machineState.Count)
    );

    return StatusCode(200);
  }
}