public static async Task Go(DbConnection connection, EventQueueItem item, IServiceProvider provider, DbTransaction transaction)
{
var type = Type.GetType(item.Action);
BaseTask resolved = null;
try
{
if (type != null)
{
resolved = (BaseTask)ActivatorUtilities.CreateInstance(provider, type, item);
await resolved.Go();
}
await connection.ExecuteAsync("DELETE from \"EventQueue\" where \"Id\" = @Id", new { Id = item.Id });
transaction.Commit();
}
catch (Exception e)
{
Console.WriteLine(e);
// failed
item.AttemptCount++;
item.NextAttempt = resolved.NextTry(item.AttemptCount);
transaction.Rollback();
await connection.ExecuteAsync("UPDATE \"EventQueue\" set \"AttemptCount\"=@AttemptCount, \"NextAttempt\"=@NextAttempt where \"Id\" = @Id", new { Attemptcount = item.AttemptCount, NextAttempt = item.NextAttempt, Id = item.Id });
}
transaction.Dispose();
}
public async void _do()
{
await Task.Delay(2000);
DateTime after = DateTime.MinValue;
while (true)
{
// set up the wait
_cancellationTokenSource?.Dispose();
_cancellationTokenSource = new CancellationTokenSource();
var sleepTime = await _getSleepTime(after);
if (sleepTime != 0)
{
try
{
if (sleepTime > 0)
{
_cancellationTokenSource.CancelAfter(sleepTime);
}
await _notifier.Subscribe(BackgroundTaskPath, (a) => _cancellationTokenSource?.Cancel());
await _connection.WaitAsync(_cancellationTokenSource.Token);
}
catch (OperationCanceledException) { }
}
_connection.Close(); // workaround for npgsql issue??
await _connection.OpenAsync();
var transaction = _connection.BeginTransaction();
var nextAction = await _connection.QuerySingleOrDefaultAsync <EventQueueItem>("SELECT * FROM \"EventQueue\" WHERE \"NextAttempt\" < @time order by \"NextAttempt\" limit 1 for update skip locked", new { time = DateTime.Now.AddMinutes(1) });
_logger.LogDebug($"Next action: {nextAction?.Action ?? "nothing"}");
if (nextAction == null)
{
transaction.Rollback();
transaction.Dispose();
continue;
}
await BaseTask.Go(_connection, nextAction, _serviceProvider, transaction);
}
}