public ConsumableResultCursor(IInternalResultCursor cursor)
{
_cursor = cursor;
}
private IDisposable StartStreaming(IInternalResultCursor cursor,
IObserver <IRecord> recordObserver = null, IObserver <IResultSummary> summaryObserver = null)
{
var cancellation = new CompositeDisposable(2);
if (summaryObserver != null)
{
cancellation.Add(_summary.Subscribe(summaryObserver));
}
if (StartStreaming())
{
if (recordObserver != null)
{
cancellation.Add(_records.Subscribe(recordObserver));
}
var streamingCancellation = new CancellationDisposable();
cancellation.Add(streamingCancellation);
Task.Run(async() =>
{
try
{
// Ensure that we propagate any errors from the KeysAsync call
await cursor.KeysAsync().ConfigureAwait(false);
if (!_records.HasObservers)
{
cursor.Cancel();
}
else
{
streamingCancellation.Token.Register(cursor.Cancel);
}
while (await cursor.FetchAsync().ConfigureAwait(false))
{
_records.OnNext(cursor.Current);
}
_records.OnCompleted();
}
catch (Exception exc)
{
_records.OnError(exc);
if (summaryObserver != null)
{
_summary.OnError(exc);
}
}
try
{
_summary.OnNext(await cursor.ConsumeAsync().ConfigureAwait(false));
_summary.OnCompleted();
}
catch (Exception exc)
{
_summary.OnError(exc);
}
CompleteStreaming();
}, streamingCancellation.Token);
}
else
{
recordObserver?.OnError(new ResultConsumedException(
"Streaming has already started and/or finished with a previous Records or Summary subscription."));
}
return(cancellation);
}
