private async Task <int> ProcessMessageCallbacks(NpgsqlConnection connection, PostgreSqlBusMessage message, List <Func <IBusMessage, Task> > callbacks, Guid queueMessageId)
{
var timer = Stopwatch.StartNew();
for (var i = 0; i < callbacks.Count; i++)
{
var callback = callbacks[i];
try
{
await callback(message).ConfigureAwait(false);
}
catch (Exception e)
{
await _db.UpdateMessageState(connection, queueMessageId, e.ToString(), MessageState.Failed).ConfigureAwait(false);
throw new CallbackExecutionException(i, queueMessageId, e);
}
}
timer.Stop();
await _db.UpdateMessageState(connection, queueMessageId, $"Time spent={timer.Elapsed};", MessageState.Completed).ConfigureAwait(false);
return(callbacks.Count);
}
private async Task <int> ProcessQueue(List <Func <IBusMessage, Task> > callbacks, string stateProcessor, Queue queue)
{
var callbackCounter = 0;
using (var connection = new NpgsqlConnection(_options.ConnectionString))
{
await connection.OpenAsync().ConfigureAwait(false);
try
{
using (var transaction = connection.BeginTransaction(IsolationLevel.ReadCommitted))
{
try
{
var queueMessageId = await _db.FetchNextQueueMessageId(connection, queue, stateProcessor).ConfigureAwait(false);
if (queueMessageId.HasValue)
{
_logger.LogDebug("Received message id: {ReceivedMessageId}", queueMessageId);
var queueMessage = await _db.FetchQueueMessageAsync(connection, queueMessageId.Value).ConfigureAwait(false);
if (queueMessage == null)
{
_logger.LogWarning("Received message not loaded by id: {ReceivedMessageId}", queueMessageId);
return(0);
}
// did we loaded wrong message?
if (queueMessage.StateProcessor != stateProcessor)
{
_logger.LogWarning(
"Received message id: '{ReceivedMessageId}' state processor does not match. Expected: {ExpectedStateProcessor}. Received: {ReceivedStateProcessor}.",
queueMessageId, stateProcessor, queueMessage.StateProcessor);
return(0);
}
var messageId = queueMessage.QueueMessageId.ToString();
var body = Encoding.UTF8.GetBytes(queueMessage.Body);
var properties = _serializer.Deserialize <IDictionary <string, object> >(queueMessage.Properties);
var busMessage = new PostgreSqlBusMessage(messageId, body, properties);
callbackCounter = await ProcessMessageCallbacks(connection, busMessage, callbacks, queueMessageId.Value).ConfigureAwait(false);
}
await transaction.CommitAsync().ConfigureAwait(false);
}
catch (CallbackExecutionException)
{
// save message state
await transaction.CommitAsync().ConfigureAwait(false);
throw;
}
catch
{
await transaction.RollbackAsync().ConfigureAwait(false);
throw;
}
}
}
finally
{
connection.Close();
}
}
return(callbackCounter);
}