public static AsyncAsyncSubject <TSource> GetAwaiter <TSource>(this IConnectableAsyncObservable <TSource> source)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
var subject = new SequentialAsyncAsyncSubject <TSource>();
var subscribeTask = source.SubscribeSafeAsync(subject);
subscribeTask.AsTask().ContinueWith(t =>
{
if (t.Exception != null)
{
subject.OnErrorAsync(t.Exception); // NB: Should not occur due to use of SubscribeSafeAsync.
}
else
{
source.ConnectAsync();
}
});
return(subject);
}
public static AsyncAsyncSubject <TSource> RunAsync <TSource>(this IConnectableAsyncObservable <TSource> source, CancellationToken token)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
var subject = new SequentialAsyncAsyncSubject <TSource>();
if (token.IsCancellationRequested)
{
var ignored = subject.OnErrorAsync(new OperationCanceledException(token));
return(subject);
}
var d = new CompositeAsyncDisposable();
var subscribeTask = source.SubscribeSafeAsync(subject);
subscribeTask.ContinueWith(t =>
{
if (t.Exception != null)
{
subject.OnErrorAsync(t.Exception); // NB: Should not occur due to use of SubscribeSafeAsync.
}
else
{
var ignored = d.AddAsync(t.Result);
source.ConnectAsync().ContinueWith(t2 =>
{
if (t2.Exception == null)
{
var ignored2 = d.AddAsync(t2.Result);
}
});
}
});
if (token.CanBeCanceled)
{
token.Register(() =>
{
var ignored = d.DisposeAsync();
});
}
return(subject);
}
public static IAsyncObservable <TSource> RefCount <TSource>(this IConnectableAsyncObservable <TSource> source)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
var gate = new AsyncLock();
var count = 0;
var connectable = default(IAsyncDisposable);
return(Create <TSource>(async observer =>
{
var subscription = await source.SubscribeSafeAsync(observer).ConfigureAwait(false);
using (await gate.LockAsync().ConfigureAwait(false))
{
if (++count == 1)
{
connectable = await source.ConnectAsync().ConfigureAwait(false);
}
}
return AsyncDisposable.Create(async() =>
{
await subscription.DisposeAsync().ConfigureAwait(false);
using (await gate.LockAsync().ConfigureAwait(false))
{
if (--count == 0)
{
await connectable.DisposeAsync().ConfigureAwait(false);
}
}
});
}));
}
