private static void SubscribeProgressToChain(Promise promise, InternalProtected.IProgressListener progressListener, ref ValueLinkedStack <InternalProtected.PromisePassThrough> passThroughs)
{
Promise next;
// If the promise is not waiting on another promise (is the root), it sets next to null, does not add the listener, and returns false.
// If the promise is waiting on another promise that is not its previous, it adds the listener, transforms progresslistener, sets next to the one it's waiting on, and returns true.
// Otherwise, it sets next to its previous, adds the listener only if it is a WaitPromise, and returns true.
while (promise.SubscribeProgressIfWaiterAndContinueLoop(ref progressListener, out next, ref passThroughs))
{
promise = next;
}
// promise is the root of the promise tree.
switch (promise._state)
{
case State.Pending:
{
progressListener.SetInitialProgress(promise.CurrentProgress());
break;
}
case State.Resolved:
{
progressListener.SetInitialProgress(promise._waitDepthAndProgress.GetIncrementedWholeTruncated());
break;
}
default: // Rejected or Canceled:
{
progressListener.Retain();
progressListener.CancelOrSetProgress(promise, promise._waitDepthAndProgress);
break;
}
}
}
protected void SubscribeProgress <TCapture>(TCapture capturedValue, Action <TCapture, float> onProgress, CancelationToken cancelationToken)
{
ValidateOperation(this, 2);
ValidateArgument(onProgress, "onProgress", 2);
if (_state == State.Pending)
{
InternalProtected.IProgressListener progressListener = InternalProtected.ProgressDelegateCapture <TCapture> .GetOrCreate(capturedValue, onProgress, this, cancelationToken);
// Directly add to listeners for this promise.
// Sets promise to the one this is waiting on. Returns false if not waiting on another promise.
Promise promise;
if (!SubscribeProgressAndContinueLoop(ref progressListener, out promise))
{
// This is the root of the promise tree.
progressListener.SetInitialProgress(_waitDepthAndProgress);
return;
}
SubscribeProgressToBranchesAndRoots(promise, progressListener);
}
else if (_state == State.Resolved)
{
Internal.AddToHandleQueueBack(InternalProtected.ProgressDelegateCapture <TCapture> .GetOrCreate(capturedValue, onProgress, this));
}
// Don't report progress if the promise is canceled or rejected.
}
private static void SubscribeProgressToBranchesAndRoots(Promise promise, InternalProtected.IProgressListener progressListener)
{
// This allows us to subscribe progress to AllPromises and RacePromises iteratively instead of recursively
ValueLinkedStack <InternalProtected.PromisePassThrough> passThroughs = new ValueLinkedStack <InternalProtected.PromisePassThrough>();
Repeat:
SubscribeProgressToChain(promise, progressListener, ref passThroughs);
if (passThroughs.IsNotEmpty)
{
// passThroughs are removed from their targets before adding to passThroughs. Add them back here.
var passThrough = passThroughs.Pop();
promise = passThrough.Owner;
progressListener = passThrough;
passThrough.Target.ReAdd(passThrough);
goto Repeat;
}
}
protected virtual bool SubscribeProgressIfWaiterAndContinueLoop(ref InternalProtected.IProgressListener progressListener, out Promise previous, ref ValueLinkedStack <InternalProtected.PromisePassThrough> passThroughs)
{
return((previous = _valueOrPrevious as Promise) != null);
}
protected virtual bool SubscribeProgressAndContinueLoop(ref InternalProtected.IProgressListener progressListener, out Promise previous)
{
progressListener.Retain();
_progressListeners.Push(progressListener);
return((previous = _valueOrPrevious as Promise) != null);
}
