private async Task OpenConnection(IDuplexPipe application, Uri url, TaskCompletionSource <object> startTcs, CancellationToken cancellationToken)
{
Log.StartReceive(_logger);
var request = new HttpRequestMessage(HttpMethod.Get, url);
SendUtils.PrepareHttpRequest(request, _httpOptions);
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("text/event-stream"));
HttpResponseMessage response;
try
{
response = await _httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
response.EnsureSuccessStatusCode();
startTcs.TrySetResult(null);
}
catch (Exception ex)
{
Log.TransportStopping(_logger);
startTcs.TrySetException(ex);
return;
}
using (var stream = await response.Content.ReadAsStreamAsync())
{
var pipeOptions = new PipeOptions(pauseWriterThreshold: 0, resumeWriterThreshold: 0);
var pipelineReader = StreamPipeConnection.CreateReader(pipeOptions, stream);
var readCancellationRegistration = cancellationToken.Register(
reader => ((PipeReader)reader).CancelPendingRead(), pipelineReader);
try
{
while (true)
{
var result = await pipelineReader.ReadAsync();
var input = result.Buffer;
if (result.IsCanceled || (input.IsEmpty && result.IsCompleted))
{
Log.EventStreamEnded(_logger);
break;
}
var consumed = input.Start;
var examined = input.End;
try
{
Log.ParsingSSE(_logger, input.Length);
var parseResult = _parser.ParseMessage(input, out consumed, out examined, out var buffer);
switch (parseResult)
{
case ServerSentEventsMessageParser.ParseResult.Completed:
Log.MessageToApp(_logger, buffer.Length);
await _application.Output.WriteAsync(buffer);
_parser.Reset();
break;
case ServerSentEventsMessageParser.ParseResult.Incomplete:
if (result.IsCompleted)
{
throw new FormatException("Incomplete message.");
}
break;
}
}
finally
{
pipelineReader.AdvanceTo(consumed, examined);
}
}
}
catch (OperationCanceledException)
{
Log.ReceiveCanceled(_logger);
}
finally
{
readCancellationRegistration.Dispose();
_transportCts.Cancel();
Log.ReceiveStopped(_logger);
}
}
}
private async Task OpenConnection(Channel <byte[], SendMessage> application, Uri url, CancellationToken cancellationToken)
{
_logger.StartReceive();
var request = new HttpRequestMessage(HttpMethod.Get, url);
SendUtils.PrepareHttpRequest(request, _httpOptions);
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("text/event-stream"));
var response = await _httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
var stream = await response.Content.ReadAsStreamAsync();
var pipelineReader = StreamPipeConnection.CreateReader(new PipeOptions(_memoryPool), stream);
var readCancellationRegistration = cancellationToken.Register(
reader => ((IPipeReader)reader).CancelPendingRead(), pipelineReader);
try
{
while (true)
{
var result = await pipelineReader.ReadAsync();
var input = result.Buffer;
if (result.IsCancelled || (input.IsEmpty && result.IsCompleted))
{
_logger.EventStreamEnded();
break;
}
var consumed = input.Start;
var examined = input.End;
try
{
var parseResult = _parser.ParseMessage(input, out consumed, out examined, out var buffer);
switch (parseResult)
{
case ServerSentEventsMessageParser.ParseResult.Completed:
_application.Writer.TryWrite(buffer);
_parser.Reset();
break;
case ServerSentEventsMessageParser.ParseResult.Incomplete:
if (result.IsCompleted)
{
throw new FormatException("Incomplete message.");
}
break;
}
}
finally
{
pipelineReader.Advance(consumed, examined);
}
}
}
catch (OperationCanceledException)
{
_logger.ReceiveCanceled();
}
finally
{
readCancellationRegistration.Dispose();
_transportCts.Cancel();
stream.Dispose();
_logger.ReceiveStopped();
}
}