public void OnPull()
{
if (_stage._maxBuffer == 0)
{
if (_pendingOffer != null)
{
Push(_stage.Out, _pendingOffer.Element);
_pendingOffer.CompletionSource.SetResult(QueueOfferResult.Enqueued.Instance);
_pendingOffer = null;
if (_terminating)
{
_completion.SetResult(new object());
CompleteStage();
}
}
}
else if (_buffer.NonEmpty)
{
Push(_stage.Out, _buffer.Dequeue());
if (_pendingOffer != null)
{
EnqueueAndSuccess(_pendingOffer);
_pendingOffer = null;
}
}
if (_terminating && _buffer.IsEmpty)
{
_completion.SetResult(new object());
CompleteStage();
}
}
public Logic(QueueSource <TOut> source, TaskCompletionSource <object> completion) : base(source.Shape)
{
_completion = completion;
_source = source;
SetHandler(source.Out,
onDownstreamFinish: () =>
{
if (_pendingOffer != null)
{
_pendingOffer.CompletionSource.SetResult(QueueOfferResult.QueueClosed.Instance);
_pendingOffer = null;
}
_completion.SetResult(new object());
CompleteStage();
},
onPull: () =>
{
if (_source._maxBuffer == 0)
{
if (_pendingOffer != null)
{
Push(source.Out, _pendingOffer.Element);
_pendingOffer.CompletionSource.SetResult(QueueOfferResult.Enqueued.Instance);
_pendingOffer = null;
if (_terminating)
{
_completion.SetResult(new object());
CompleteStage();
}
}
}
else if (_buffer.NonEmpty)
{
Push(source.Out, _buffer.Dequeue());
if (_pendingOffer != null)
{
EnqueueAndSuccess(_pendingOffer);
_pendingOffer = null;
}
}
if (_terminating && _buffer.IsEmpty)
{
_completion.SetResult(new object());
CompleteStage();
}
});
}
public Logic(QueueSource <TOut> source) : base(source.Shape)
{
_source = source;
SetHandler(source.Shape.Outlet,
onDownstreamFinish: () =>
{
if (_pendingOffer != null)
{
var promise = _pendingOffer.Item2;
promise.SetResult(QueueOfferResult.QueueClosed.Instance);
_pendingOffer = null;
}
_source._completion.SetResult(new object());
CompleteStage();
},
onPull: () =>
{
if (_source._maxBuffer == 0)
{
if (_pendingOffer != null)
{
var element = _pendingOffer.Item1;
var promise = _pendingOffer.Item2;
Push(source.Shape.Outlet, element);
promise.SetResult(QueueOfferResult.Enqueued.Instance);
_pendingOffer = null;
}
else
{
_pulled = true;
}
}
else if (!_buffer.IsEmpty)
{
Push(source.Shape.Outlet, _buffer.Dequeue());
if (_pendingOffer != null)
{
var element = _pendingOffer.Item1;
var promise = _pendingOffer.Item2;
EnqueueAndSuccess(element, promise);
}
}
else
{
_pulled = true;
}
});
}
protected virtual bool RequestElement(object message)
{
if (message is Request)
{
// totalDemand is tracked by base
if (BufferSize != 0)
{
while (TotalDemand > 0L && !Buffer.IsEmpty)
{
OnNext(Buffer.Dequeue());
}
}
return(true);
}
return(false);
}
private void PushOut()
{
var src = _q.Dequeue();
Push(_stage._out, src.Grab());
if (!src.IsClosed)
{
src.Pull();
}
else
{
RemoveSource(src);
}
}
private void SendDownstream(TaskCompletionSource <Option <T> > promise)
{
var e = _buffer.Dequeue();
if (e.IsSuccess)
{
promise.SetResult(e.Value);
if (!e.Value.HasValue)
{
CompleteStage();
}
}
else
{
promise.SetException(e.Exception);
FailStage(e.Exception);
}
}
/// <summary> /// TBD /// </summary> /// <returns>TBD</returns> public T Dequeue() => _q.Dequeue();