private async void OnAccept(Stream stream)
{
try
{
using (stream)
{
var onSendingHeadersCallbacks = new List <(Action <object>, object)>();
var owinContext = new OwinContext();
// this is an owin extension
owinContext.Set <Action <Action <object>, object> >("server.OnSendingHeaders", (callback, state) =>
{
onSendingHeadersCallbacks.Add((callback, state));
});
owinContext.Set("owin.Version", "1.0");
_logger.WriteVerbose("Server: reading message..");
await PopulateRequestAsync(stream, owinContext.Request, CancellationToken.None).ConfigureAwait(false);
// some transports (shuch as Named Pipes) may require the server to read some data before being able to get the
// client identity. So we get the client identity after reading the request headers
var transportIdentity = _listener.GetTransportIdentity(stream);
owinContext.Request.User = transportIdentity;
_logger.WriteVerbose("Server: finished reading message");
Func <Task> sendHeadersAsync = async() =>
{
// notify we are sending headers
foreach ((var callback, var state) in onSendingHeadersCallbacks)
{
callback(state);
}
// send status and headers
string statusCode = owinContext.Response.StatusCode.ToString();
_logger.WriteVerbose("Server: Statuscode was " + statusCode);
await stream.WriteServerResponseStatusAndHeadersAsync(owinContext.Request.Protocol, statusCode, owinContext.Response.ReasonPhrase, owinContext.Response.Headers.Select(i => new KeyValuePair <string, IEnumerable <string> >(i.Key, i.Value)), _logger.WriteVerbose, CancellationToken.None).ConfigureAwait(false);
_logger.WriteVerbose("Server: Wrote status and headers.");
await stream.FlushAsync().ConfigureAwait(false);
};
var body = new WriteInterceptStream(stream, sendHeadersAsync);
owinContext.Response.Body = body;
// execute higher level middleware
_logger.WriteVerbose("Server: executing middleware..");
try
{
await _app(owinContext.Environment).ConfigureAwait(false);
}
catch (Exception e)
{
await HandleMiddlewareException(e, owinContext, body);
}
_logger.WriteVerbose("Server: finished executing middleware..");
await body.FlushAsync().ConfigureAwait(false);
_logger.WriteVerbose("Server: Finished request. Disposing connection.");
}
}
catch (EndOfStreamException e)
{
_logger.WriteWarning("Server: Error handling client stream, (Client disconnected early / invalid HTTP request)", e);
}
catch (Exception e)
{
_logger.WriteError("Server: Error handling client stream " + e);
}
}
private async Task HandleMiddlewareException(Exception e, OwinContext owinContext, WriteInterceptStream body)
{
var logMessage = "Exception trying to execute middleware: " + e;
_logger.WriteError(logMessage);
owinContext.Response.StatusCode = 500;
var payload = Encoding.ASCII.GetBytes("Exception trying to execute middleware. See logs for details.");
await body.WriteAsync(payload, 0, payload.Length).ConfigureAwait(false);
await body.WriteAsync(_eol, 0, _eol.Length).ConfigureAwait(false);
}