public async Task ProcessAsync(IInvocationContext context, Message message)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (message == null)
{
throw new ArgumentNullException(nameof(message));
}
var messageContext = new MessageInvocationContext(context.Principal, message, this);
// when messages arrive through the listener there is not difference between
// messages and queries, since the result should be delivered over the queue.
if (IsQuery(message.Body))
{
await InvokeQueryHandler(messageContext, message);
}
else
{
await InvokeMessageHandlers(messageContext, message);
}
// someone else is taking care of the outbound messages
if (_outboundMessageRouter != null)
{
Logger?.Invoke(LogLevel.Debug, "", "Invoking IOutboundMessageRouter.");
await _outboundMessageRouter.SendAsync(messageContext);
}
foreach (var msg in messageContext.OutboundMessages)
{
Logger?.Invoke(LogLevel.Info, message.MessageId.ToString("N"), $"Sending {msg.Body.GetType()}");
await context.SendAsync(msg);
}
foreach (var msg in messageContext.Replies)
{
Logger?.Invoke(LogLevel.Info, message.MessageId.ToString("N"), $"Replying with {msg.Body.GetType()}");
await context.ReplyAsync(msg);
}
}
private async Task InvokeQueryHandler(MessageInvocationContext context, Message message)
{
var resultType = GetQueryResultType(message.Body);
var handlerType = typeof(IQueryHandler <,>).MakeGenericType(message.Body.GetType(), resultType);
var handlers = _scope.Create(handlerType).ToList();
if (handlers.Count == 0)
{
throw new NoHandlerRegisteredException($"Missing handler for query '{message.Body}'.");
}
if (handlers.Count > 1)
{
throw new OnlyOneQueryHandlerAllowedException(
$"Queries may only have one handler, '{message.Body}' got [{string.Join(", ", handlers.Select(x => x.GetType().FullName))}].");
}
var handler = handlers[0];
Task task;
Stopwatch sw = null;
var args1 = new InvokingHandlerEventArgs(_scope, handler, message)
{
Principal = context.Principal
};
try
{
if (HandlerInvoked != null)
{
sw = Stopwatch.StartNew();
}
InvokingHandler?.Invoke(this, args1);
task = (Task)handler
.GetType()
.GetMethod("HandleAsync")
.Invoke(handler, new[] { context, message.Body });
await task;
sw?.Stop();
var e = new HandlerInvokedEventArgs(_scope, handler, message, args1, sw?.Elapsed ?? TimeSpan.Zero)
{
Principal = context.Principal
};
HandlerInvoked?.Invoke(this, e);
}
catch (Exception ex)
{
var e = new HandlerInvokedEventArgs(_scope, handler, message, args1.ApplicationState,
sw?.Elapsed ?? TimeSpan.Zero)
{
Exception = ex
};
HandlerInvoked?.Invoke(this, e);
ExceptionDispatchInfo.Capture(ex).Throw();
return;
}
var resultProperty = typeof(Task <>).MakeGenericType(resultType).GetProperty("Result");
var result = resultProperty.GetValue(task);
await context.ReplyAsync(result);
}
