public async Task ExecuteAsync(string streamName, IObserver <IEvent> observer,
CancellationToken cancellationToken)
{
var goOn = true;
var iteration = 0;
while (goOn && !cancellationToken.IsCancellationRequested)
{
int pos = iteration * batchSize;
iteration++;
StreamEventsSlice result = await connection.ReadStreamEventsForwardAsync(streamName, pos, batchSize, false);
goOn = !result.IsEndOfStream;
foreach (ResolvedEvent item in result.Events)
{
IEvent @event = eventTransformer.FromResolvedEvent(item);
if (@event != null)
{
observer.OnNext(@event);
}
else
{
//If a event could not be created from the data, a placeholder event should be created to maintain the number and order of the total events
observer.OnNext(new SubstitutionEvent(item.OriginalStreamId, item.OriginalEventNumber, item.Event.Metadata, item.Event.Data));
HandleEventCreationFailure(item);
}
}
}
observer.OnCompleted();
}
public void Handle(EventStoreCatchUpSubscription sub, ResolvedEvent @event)
{
IEvent result = null;
try
{
result = transformer.FromResolvedEvent(@event);
}
catch (Exception err)
{
Console.WriteLine(
$"Error parsing event {@event.OriginalStreamId}/{@event.OriginalEventNumber}; Msg: {err.Message}");
}
if (result != null)
{
long pos = @event.OriginalEventNumber;
eventSub.OnNext(new OccuredEvent(pos, result));
}
}