/*The PipeMessage method is what will connect to the IoT Edge Hub and will queue the shelf data
* for processing.
*
* It will be registered as an inputMessageHandler with the IoT Edge Hub in the ExecuteAsync method
* that follows.
*/
public async Task <MessageResponse> PipeMessage(Message message, object userContext)
{
var moduleClient = userContext as ModuleClient;
if (moduleClient == null)
{
throw new InvalidOperationException("UserContext doesn't contain " + "expected values");
}
/*This section receives the data from the IoT Edge Hub and converts it to a Shelf object
* for processing through signalR to the WebApp module.
*/
byte[] messageBytes = message.GetBytes();
string messageString = Encoding.UTF8.GetString(messageBytes);
if (!string.IsNullOrEmpty(messageString))
{
try
{
_logger.LogInformation($"Receiving Message: {messageString.TrimStart('"').TrimEnd('"').Replace('\\', ' ')}");
Payload productData = JsonConvert.DeserializeObject <Payload>
(messageString.TrimStart('"').TrimEnd('"').Replace("\\", String.Empty));
PayloadQueue.QueuePayload(productData);
if (PayloadQueue.Count() > 1)
{
while (PayloadQueue.Count() > 1)
{
await PayloadQueue.DequeueAsync(new CancellationToken()); //throw away result
_logger.LogInformation("Dequeue extra data");
}
}
// catch and swallow exceptions
}
catch (AggregateException ex)
{
_logger.LogError($"Error processing message: {ex.Flatten()}");
}
catch (Exception ex)
{
_logger.LogError($"Error processing message: {ex}");
}
}
return(MessageResponse.Completed);
}
protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
/*hubContext allows ClientNotifier to act as a part of the signalR hub and send messages. See this
* for more information: https://docs.microsoft.com/en-us/aspnet/core/signalr/hubcontext?view=aspnetcore-2.1 */
var notifytask = Task.Run(async() =>
{
while (!stoppingToken.IsCancellationRequested)
{
if (PayloadQueue.Count() > 0)
{
await this.HubContext.Clients.All.SendAsync("NewData");
}
await Task.Delay(TimeSpan.FromSeconds(1));
}
}, stoppingToken);
await Task.WhenAll(notifytask);
}
