/// <summary>
/// Attaches a <see cref="StreamingRequestHandler"/> to process requests via the connected named pipe
/// and begins listening for incoming traffic.
/// </summary>
/// <param name="bot">The bot to use when processing messages.</param>
/// <param name="middleware">The middleware the bot will execute as part of the pipeline.</param>
/// <param name="onTurnError">Callback to execute when an error occurs while executing the pipeline.</param>
public void InitializeNamedPipeServer(IBot bot, IList <IMiddleware> middleware = null, Func <ITurnContext, Exception, Task> onTurnError = null)
{
if (bot == null)
{
throw new ArgumentNullException(nameof(bot));
}
middleware = middleware ?? new List <IMiddleware>();
var handler = new StreamingRequestHandler(onTurnError, bot, middleware);
StartServer(handler);
}
private async Task CreateStreamingServerConnectionAsync(Func <ITurnContext, Exception, Task> onTurnError, List <Builder.IMiddleware> middlewareSet, HttpContext httpContext)
{
var handler = new StreamingRequestHandler(onTurnError, httpContext.RequestServices, middlewareSet);
var socket = await httpContext.WebSockets.AcceptWebSocketAsync().ConfigureAwait(false);
try
{
await handler.StartAsync(socket).ConfigureAwait(false);
}
catch (Exception ex)
{
httpContext.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
await httpContext.Response.WriteAsync("Unable to create transport server.").ConfigureAwait(false);
throw ex;
}
}
private void StartServer(StreamingRequestHandler handler)
{
try
{
Task.Run(() => handler.StartAsync(_pipeName));
}
catch (Exception ex)
{
/* The inability to establish a named pipe connection is not a terminal condition,
* and should not interrupt the bot's initialization sequence. We log the failure
* as informative but do not throw an exception or cause a disruption to the bot,
* as either would require developers to spend time and effort on a feature they
* may not care about or intend to make use of.
* As our support for named pipe bots evolves we will likely be able to restrict
* connection attempts to when they're likely to succeed, but for now it's possible
* a bot will check for a named pipe connection, find that one does not exist, and
* simply continue to serve as an HTTP and/or WebSocket bot, none the wiser.
*/
_logger.LogInformation(string.Format("Failed to create server: {0}", ex));
}
}