public IIncludeForRetry Subscribe <TSubscriber, TRequest>(AbstractValidator <TRequest> validator) where TSubscriber : IResponder <TRequest> where TRequest : class
{
//subscriber registration in a container
Injection.AddTransient(typeof(TSubscriber));
//retry handler
IRetry retryHandler = new RetryHandler(MIN_RETRY_DELAY, MAX_RETRY_DELAY, RETRY_LIMIT, true);
//creates queue and exchange
string directory = typeof(TRequest).GetTypeInfo().GetCustomAttribute <BusNamespace>().Directory;
string subdirectory = typeof(TRequest).GetTypeInfo().GetCustomAttribute <BusNamespace>().Subdirectory;
string exchange = "request_" + directory.ToLower() + "_" + subdirectory.ToLower();
string routingKey = typeof(TRequest).Name.ToLower();
string queue = _appId.ToLower() + "-request-" + directory.ToLower() + "-" + subdirectory.ToLower() + "-" + typeof(TRequest).Name.ToLower();
_responderChannel.ExchangeDeclare(exchange, ExchangeType.Direct, true, false);
_responderChannel.QueueDeclare(queue, true, false, false, new Dictionary <string, object> {
{ "x-message-ttl", (int)REQUEST_TIMEOUT }, { "x-queue-mode", "default" }
});
_responderChannel.QueueBind(queue, exchange, routingKey);
//request listener
EventingBasicConsumer consumer = new EventingBasicConsumer(_responderChannel);
consumer.Received += (obj, args) =>
{
Task.Factory.StartNew(async() =>
{
//request message
string messageBody = Encoding.UTF8.GetString(args.Body.ToArray());
//tracing data
string traceSpanId = Encoding.UTF8.GetString((byte[])args.BasicProperties.Headers["TraceSpanId"]);
string traceId = Encoding.UTF8.GetString((byte[])args.BasicProperties.Headers["TraceId"]);
string traceDisplayName = "Respond-" + directory + "." + subdirectory + "." + typeof(TRequest).Name;
//response action
ResponseWrapper <object> responseWrapper = null;
await retryHandler.ExecuteAsync(async() =>
{
TRequest messageRequest = _jsonConverter.Deserialize <TRequest>(messageBody);
if (validator != null)
{
await validator.ValidateAndThrowAsync(messageRequest, (directory + "." + subdirectory + "." + messageRequest.GetType().Name + " is not valid"));
}
using (IServiceScope serviceScope = _serviceProvider.CreateScope())
using (ITraceScope traceScope = (traceSpanId != "" && traceId != "") ? new TraceScope(traceSpanId, traceId, traceDisplayName, _tracer) : new TraceScope(traceDisplayName, _tracer))
{
TSubscriber subscriber = serviceScope.ServiceProvider.GetService <TSubscriber>();
subscriber.Bus = this;
subscriber.TraceScope = traceScope;
traceScope.Attributes.Add("AppId", _appId);
traceScope.Attributes.Add("MessageId", args.BasicProperties.MessageId);
responseWrapper = new ResponseWrapper <object>(await subscriber.RespondAsync(messageRequest));
}
_logger.Send(new MessageDetail
{
Id = args.BasicProperties.MessageId,
CorrelationId = args.BasicProperties.CorrelationId,
Type = MessageType.Request,
Directory = directory,
Subdirectory = subdirectory,
Name = typeof(TRequest).Name,
Body = messageBody,
AppId = args.BasicProperties.AppId,
Exception = null,
ToRetry = false
});
},
async(exception, retryIndex, retryLimit) =>
{
responseWrapper = new ResponseWrapper <object>(exception);
_logger.Send(new MessageDetail
{
Id = args.BasicProperties.MessageId,
CorrelationId = args.BasicProperties.CorrelationId,
Type = MessageType.Request,
Directory = directory,
Subdirectory = subdirectory,
Name = typeof(TRequest).Name,
Body = messageBody,
AppId = args.BasicProperties.AppId,
Exception = exception,
ToRetry = retryIndex != retryLimit
});
await Task.CompletedTask;
});
//response message
if (typeof(TSubscriber).GetMethod("RespondAsync").GetCustomAttribute <FakeResponse>() == null)
{
messageBody = _jsonConverter.Serialize(responseWrapper);
IBasicProperties properties = _responderChannel.CreateBasicProperties();
properties.MessageId = Guid.NewGuid().ToString();
properties.Persistent = false;
properties.CorrelationId = args.BasicProperties.CorrelationId;
_responderChannel.BasicPublish("", args.BasicProperties.ReplyTo, properties, Encoding.UTF8.GetBytes(messageBody));
_logger.Send(new MessageDetail
{
Id = properties.MessageId,
CorrelationId = properties.CorrelationId,
Type = MessageType.Response,
Directory = directory,
Subdirectory = subdirectory,
Name = typeof(TRequest).Name,
Body = messageBody,
AppId = args.BasicProperties.AppId,
Exception = null,
ToRetry = false
});
}
//acknowledgment
_responderChannel.BasicAck(args.DeliveryTag, false);
},
_cancellationTokenSource.Token,
TaskCreationOptions.DenyChildAttach,
TaskScheduler.Default);
};
_toActivateConsumers.Add(new Tuple <IModel, string, EventingBasicConsumer>(_responderChannel, queue, consumer));
return(retryHandler);
}
private async Task <bool> Validate(CreateInventoryItemCommand command)
{
await validator.ValidateAndThrowAsync(command);
return(true);
}
public async Task Handle(TRequest request)
{
await _validator.ValidateAndThrowAsync(request);
}
public async Task <TResponse> Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate <TResponse> next)
{
await _validator.ValidateAndThrowAsync(request);
return(await next());
}
private async Task <bool> Validate(CreatePurchaseOrderCommand command)
{
await validator.ValidateAndThrowAsync(command);
return(true);
}