public IDisposable GetOrAdd <TScope, TService>(
TScope scope,
out TService service,
out bool wasAdded,
Func <TScope, TService> serviceFactory)
{
lock (registrations) {
if (TryGet(scope, out service))
{
wasAdded = false;
return(DelegateDisposable.NoOp());
}
service = serviceFactory(scope);
if (service == null)
{
throw new ArgumentException(
$"{nameof(service)} result is null for {typeof(TService).GetFriendlyFullName()}"
+ $" --- for scope '{scope}'.",
nameof(serviceFactory));
}
if (!registrations.TryGetValue(typeof(TScope), out Dictionary <object, object> scopes))
{
scopes = new Dictionary <object, object>(8);
registrations[typeof(TScope)] = scopes;
}
else
{
Debug.Assert(!scopes.ContainsKey(scope), "!scopes.ContainsKey(scope)");
}
scopes[scope] = service;
wasAdded = true;
return(DelegateDisposable.With(scope, s => Remove(typeof(TScope), s)));
}
}
