public async Task <Stream> SendAsync(IQueuedRequest request)
{
while (true)
{
try
{
return(await SendAsyncInternal(request).ConfigureAwait(false));
}
catch (HttpRateLimitException ex)
{
//When a 429 occurs, we drop all our locks.
//This is generally safe though since 429s actually occuring should be very rare.
RequestQueueBucket bucket;
bool success = FindBucket(ex.BucketId, out bucket);
await _queue.RaiseRateLimitTriggered(ex.BucketId, success?bucket.Definition : null, ex.RetryAfterMilliseconds).ConfigureAwait(false);
bucket.Pause(ex.RetryAfterMilliseconds);
}
}
}
private async Task <Stream> SendAsyncInternal(IQueuedRequest request)
{
var endTick = request.TimeoutTick;
//Wait until a spot is open in our bucket
if (_semaphore != null)
{
await EnterAsync(endTick).ConfigureAwait(false);
}
try
{
while (true)
{
//Get our 429 state
Task notifier;
int resumeTime;
lock (_pauseLock)
{
notifier = _resumeNotifier.Task;
resumeTime = _pauseEndTick;
}
//Are we paused due to a 429?
if (!notifier.IsCompleted)
{
//If the 429 ends after the maximum time for this request, timeout immediately
if (endTick.HasValue && endTick.Value < resumeTime)
{
throw new TimeoutException();
}
//Wait for the 429 to complete
await notifier.ConfigureAwait(false);
}
try
{
//If there's a parent bucket, pass this request to them
if (Parent != null)
{
return(await Parent.SendAsyncInternal(request).ConfigureAwait(false));
}
//We have all our semaphores, send the request
return(await request.SendAsync().ConfigureAwait(false));
}
catch (HttpException ex) when(ex.StatusCode == HttpStatusCode.BadGateway)
{
continue;
}
}
}
finally
{
//Make sure we put this entry back after WindowMilliseconds
if (_semaphore != null)
{
QueueExitAsync();
}
}
}
