protected virtual void QueryStorage(List <int> activeDeliveryTypes)
{
//update query state
_lastQueryTimeUtc = DateTime.UtcNow;
_lastQueryKeys = activeDeliveryTypes;
_isLastQueryMaxItemsReceived = false;
//query items
Stopwatch storageQueryTimer = Stopwatch.StartNew();
DateTime lockStartUtc = DateTime.UtcNow;
List <SignalDispatch <TKey> > items = null;
try
{
items = PickStorageQuery(activeDeliveryTypes);
}
catch (Exception ex)
{
items = new List <SignalDispatch <TKey> >();
_logger.LogError(ex, SenderInternalMessages.DatabaseDispatchProvider_DatabaseError);
}
storageQueryTimer.Stop();
//enqueue items for processing
_dispatchQueue.Append(items, true);
//turn on database event tracking
_isLastQueryMaxItemsReceived = items.Count == ItemsQueryCount;
if (_changeNotifier != null && _isLastQueryMaxItemsReceived == false)
{
_changeNotifier.StartMonitor();
}
//store metrics
_monitor.DispatchPersistentStorageQueried(storageQueryTimer.Elapsed, items);
//remember processed items, not to query them again while processing
_lockTracker.RememberLock(items.Select(x => x.SignalDispatchId), lockStartUtc);
}