protected override async Task RunAsync(IReadOnlyList <Func <Task> > messages)
{
if (!IsReady)
{
// Do not do anything until the stream has finished loading.
return;
}
// Every time we wake up, we expect the wrapper to refresh itself, either
// as a consequence of one of the messages (i.e. a write) or because it
// detects that a state refresh was requested.
var _ = Wrapper.WaitForState();
foreach (var msg in messages)
{
try
{
await msg().ConfigureAwait(false);
}
catch
{
// TODO: log this
}
}
// If someone asked for a refresh, and it has not been satisfied by the
// above messages, perform a refresh automatically.
if (Wrapper.WaitingForState)
{
await Wrapper.CatchUpAsync(_cancel).ConfigureAwait(false);
}
}
/// <summary> Retrieve the current state. </summary>
/// <remarks>
/// The returned state includes all events written to the remote stream
/// until the moment this function is called.
/// </remarks>
public Task <TState> CurrentState(CancellationToken cancel)
{
if (!IsReady)
{
throw new StreamNotReadyException();
}
var syncStep = Wrapper.SyncStep;
return(EnqueueAction(async c =>
{
if (syncStep == Wrapper.SyncStep)
{
await Wrapper.CatchUpAsync(c).ConfigureAwait(false);
}
return Wrapper.Current;
}, cancel));
}