private async Task _processMessage(
QMessage qMessage,
Type messageType,
Type modelType,
object processor,
Message receivedMessage)
{
_settings.Logger?.Debug("Executing processor message received.", qMessage.Id);
await _executeAsyncMethod(Constants.MethodNames.Received,
messageType, processor, _obj(receivedMessage, _settings.Logger));
_settings.Logger?.Debug("Deserializing message body.", qMessage.Id);
var body = Newtonsoft.Json.JsonConvert.DeserializeObject(receivedMessage.Body, modelType);
_settings.Logger?.Debug("Executing processor message validation.", qMessage.Id);
var validatedModel = await _executeAsyncMethod <object>(Constants.MethodNames.Validate,
messageType, processor, _obj(receivedMessage, body, _settings.Logger));
if (validatedModel != null)
{
_settings.Logger?.Debug("Executing processor message processing.", qMessage.Id);
var reply = await _executeAsyncMethod <QReply>(Constants.MethodNames.Process,
messageType, processor, _obj(receivedMessage, validatedModel, _settings.Logger));
if (reply != null && !string.IsNullOrEmpty(reply.ReplyToQueueUrl))
{
await SendAsync(reply.Message, reply.ReplyToQueueUrl);
}
if (_settings.DeleteIfSuccess)
{
await DeleteAsync(qMessage);
}
}
else
{
_settings.Logger?.Debug("Message with id {Id} was marked invalid by processor and execution has stopped.",
qMessage.Id);
if (_settings.DeleteIfInvalid)
{
await DeleteAsync(qMessage);
}
}
}
/// <summary>
/// Delete a message from a queue.
/// </summary>
/// <param name="message">The QMessage to delete.</param>
/// <returns>Task</returns>
/// <exception cref="Exception">Throws if delete fails.</exception>
public async Task DeleteAsync(
QMessage message)
{
var result = await
_sqsClient.DeleteMessageAsync(new DeleteMessageRequest(_settings.QueueUrl,
message.AwsSqsMessage.ReceiptHandle));
if (result.HttpStatusCode == HttpStatusCode.OK)
{
_settings.Logger?.Debug("Message id {id} deleted from queue.", message.Id);
}
else
{
throw new Exception($"Error deleting message id {message.Id} to queue {_settings.QueueUrl}.");
}
}
/// <summary>
/// Send an SQS message to the specified queue url.
/// </summary>
/// <param name="message">QMessage to send.</param>
/// <param name="queueUrl">Queue url to send to.</param>
/// <returns>Task</returns>
/// <exception cref="Exception">Throws if not successful.</exception>
public async Task SendAsync(
QMessage message,
string queueUrl)
{
var result = await _sqsClient.SendMessageAsync(new SendMessageRequest()
{
MessageBody = message.Body,
QueueUrl = queueUrl,
MessageAttributes = message.MessageAttributes
});
if (result.HttpStatusCode == HttpStatusCode.OK)
{
_settings.Logger?.Debug("Sent message {MessageId} to queue {queueUrl}.", result.MessageId, queueUrl);
}
else
{
throw new Exception($"Error sending message to queue {queueUrl}.");
}
}
/// <summary>
/// Polls the queue url specified in the QBrokerSettings and processes according to the added processors.
/// </summary>
/// <returns>Task</returns>
/// <exception cref="Exception"></exception>
public async Task FetchAsync()
{
while (true)
{
_settings.Logger?.Information("Fetching queue messages.");
var received = await _readMessages();
if (received.HttpStatusCode != HttpStatusCode.OK)
{
throw new Exception($"Unable to read messages from queue {_settings.QueueUrl}. AWS responded with code {received.HttpStatusCode}.");
}
if (received.Messages.Count <= 0)
{
return;
}
_settings.Logger?.Information("Processing {Count} messages.", received.Messages.Count);
foreach (var receivedMessage in received.Messages)
{
QMessage qMessage;
try
{
qMessage = new QMessage(receivedMessage);
}
catch (ArgumentException)
{
_settings.Logger?
.Debug("Message id {Id} does not appear to be a valid QBroker message and will be skipped.",
receivedMessage.MessageId);
continue;
}
_settings.Logger?.Debug("Processing message with id {Id}.", qMessage.Id);
var messageVersion = Semver.SemVersion.Parse(qMessage.Version);
var compare = SemVersion.Compare(messageVersion, Constants.Library.SemVersion);
switch (compare)
{
case -1:
_settings.Logger?.Warning(
"Message id {id} was created using version {messageVersion} which is older than this version {currentVersion}",
qMessage.Id, messageVersion, Constants.Library.Version);
break;
case 1:
_settings.Logger?.Warning(
"Message id {id} was created using version {messageVersion} which is newer than this version {currentVersion}",
qMessage.Id, messageVersion, Constants.Library.Version);
break;
}
if (!_messageTypes.ContainsKey(qMessage.Name))
{
_settings.Logger?.Debug("Skipping message id {Id}. No processor found for message name.", qMessage.Id);
continue;
}
var messageType = _messageTypes[qMessage.Name];
var modelType = _modelTypes[qMessage.Name];
var processor = _serviceProvider == null
? Activator.CreateInstance(messageType)
: ActivatorUtilities.CreateInstance(_serviceProvider, messageType);
try
{
await _processMessage(qMessage, messageType, modelType, processor, receivedMessage);
}
catch (Exception e)
{
_settings.Logger?.Debug("Executing processor message error for message id {id}.", qMessage.Id);
await _executeAsyncMethod(Constants.MethodNames.Error, messageType, processor,
_obj(receivedMessage, e, _settings.Logger));
if (_settings.DeleteIfError)
{
await DeleteAsync(qMessage);
}
}
}
if (_settings.FetchUntilEmpty)
{
continue;
}
break;
}
}