private async Task FetchAndProcess(TimeSpan startupDelay, CancellationToken cancellationToken)
{
var numberRetrievedInLastBatch = 0;
if (startupDelay > TimeSpan.Zero)
{
await Task.Delay(startupDelay).ConfigureAwait(false);
}
while (!cancellationToken.IsCancellationRequested)
{
try
{
var messages = await messageSource
.WaitForNextMessageBatch(
batchSizeProvider.CalculateNewRecommendedBatchSize(numberRetrievedInLastBatch),
cancellationToken)
.ConfigureAwait(false);
numberRetrievedInLastBatch = messages?.Count ?? 0;
await pipeline
.Process(messages, cancellationToken)
.ConfigureAwait(false);
}
catch (TaskCanceledException)
{
break;
}
catch (Exception exception)
{
// Cannot stop the loop as a subscriber would silently just fail. Need to log and try again.
logger.LogError(exception, "Unhandled exception when checking for messages.");
}
}
}