public IDisposable Subscribe(IObserver <T> observer)
{
if (observer == null)
{
throw new ArgumentNullException(nameof(observer));
}
IObserver <T> original;
IObserver <T> nextState;
do
{
original = _current;
if (original == FastSubjectHelpers <T> .DisposedSubjectMarker)
{
throw new ObjectDisposedException("");
}
if (original == FastSubjectHelpers <T> .CompletedSubjectMarker)
{
observer.OnCompleted();
return(Disposable.Empty);
}
if (original is FastSubjectHelpers <T> .ExceptionedSubject)
{
observer.OnError(((FastSubjectHelpers <T> .ExceptionedSubject)original).Error);
return(Disposable.Empty);
}
if (original == FastSubjectHelpers <T> .EmptySubjectMarker)
{
nextState = observer;
}
else if (original is FastSubjectHelpers <T> .MultiSubject)
{
var originalArray = ((FastSubjectHelpers <T> .MultiSubject)original).Array;
var originalCount = originalArray.Length;
var newArray = new IObserver <T> [originalCount + 1];
Array.Copy(originalArray, newArray, originalCount);
newArray[originalCount] = observer;
nextState = new FastSubjectHelpers <T> .MultiSubject(newArray);
}
else
{
nextState = new FastSubjectHelpers <T> .MultiSubject(new[] { original, observer });
}
} while (Interlocked.CompareExchange(ref _current, nextState, original) != original);
return(new FastSubjectHelpers <T> .Subscription(this, observer));
}
public void Unsubscribe(IObserver <T> observer)
{
IObserver <T> original;
IObserver <T> nextState;
do
{
original = _current;
if (original is IStoppedSubjectMarker)
{
return;
}
if (original is FastSubjectHelpers <T> .MultiSubject)
{
var originalArray = ((FastSubjectHelpers <T> .MultiSubject)original).Array;
var indexOf = Array.IndexOf(originalArray, observer);
if (indexOf < 0)
{
return;
}
if (originalArray.Length == 2)
{
nextState = originalArray[1 - indexOf];
}
else
{
var newArray = new IObserver <T> [originalArray.Length - 1];
Array.Copy(originalArray, newArray, indexOf);
Array.Copy(originalArray, indexOf + 1, newArray, indexOf, newArray.Length - indexOf);
nextState = new FastSubjectHelpers <T> .MultiSubject(newArray);
}
}
else
{
if (original != observer)
{
return;
}
nextState = FastSubjectHelpers <T> .EmptySubjectMarker;
}
} while (Interlocked.CompareExchange(ref _current, nextState, original) != original);
}
public void OnNext(T value)
{
IObserver <T> original;
IObserver <T> nextState;
do
{
original = _current;
if (original is FastSubjectHelpers <T> .SingleSubjectWithValue)
{
nextState = new FastSubjectHelpers <T> .SingleSubjectWithValue(
((FastSubjectHelpers <T> .SingleSubjectWithValue)original).Observer, value);
}
else if (original is FastSubjectHelpers <T> .EmptySubjectWithValue || original == FastSubjectHelpers <T> .EmptySubjectMarker)
{
nextState = new FastSubjectHelpers <T> .EmptySubjectWithValue(value);
}
else if (original is FastSubjectHelpers <T> .MultiSubjectWithValue)
{
nextState = new FastSubjectHelpers <T> .MultiSubjectWithValue(
((FastSubjectHelpers <T> .MultiSubjectWithValue)original).Array, value);
}
else if (original is FastSubjectHelpers <T> .MultiSubject)
{
nextState = new FastSubjectHelpers <T> .MultiSubjectWithValue(
((FastSubjectHelpers <T> .MultiSubject)original).Array, value);
}
else if (original is IStoppedSubjectMarker)
{
break;
}
else
{
nextState = new FastSubjectHelpers <T> .SingleSubjectWithValue(original, value);
}
} while (Interlocked.CompareExchange(ref _current, nextState, original) != original);
original.OnNext(value);
}
