public void Publish(IntegrationEvent evt)
{
if (!_persistentConnection.IsConnected)
{
_persistentConnection.TryConnect();
}
var policy = RetryPolicy.Handle <BrokerUnreachableException>()
.Or <SocketException>()
.WaitAndRetry(_retryCount, retryAttempt => TimeSpan.FromSeconds(Math.Pow(2, retryAttempt)), (ex, time) =>
{
_logger.LogWarning(ex, "Could not publish event: {EventId} after {Timeout}s ({ExceptionMessage})", evt.EventId, $"{time.TotalSeconds:n1}", ex.Message);
});
var eventName = evt.GetNormalizeTypeName();
_logger.LogTrace("Creating RabbitMQ channel to publish event: {EventId} ({EventName})", evt.EventId, eventName);
_logger.LogTrace("Declaring RabbitMQ exchange to publish event: {EventId}", evt.EventId);
using var channel = GetChannelWithDeclare(evt.BusParams);
channel.QueueBind(evt.BusParams.QueueName, evt.BusParams.ExchangeName, eventName);
var message = JsonSerializer.Serialize(evt, evt.GetType(), new JsonSerializerOptions
{
WriteIndented = false,
Encoder = JavaScriptEncoder.Create(UnicodeRanges.BasicLatin, UnicodeRanges.Cyrillic)
});
var body = Encoding.UTF8.GetBytes(message);
policy.Execute(() =>
{
var properties = channel.CreateBasicProperties();
properties.DeliveryMode = 2; // persistent
_logger.LogTrace("Publishing event to RabbitMQ: {EventId}", evt.EventId);
channel.BasicPublish(
exchange: evt.BusParams.ExchangeName,
routingKey: eventName,
mandatory: true,
basicProperties: properties,
body: body);
});
}
private async Task ProcessEvent(IntegrationEvent iEvent)
{
var eventName = iEvent.GetNormalizeTypeName();
_logger.LogDebug("Processing event: {EventName}", eventName);
if (_subsManager.HasSubscriptionsForEvent(eventName))
{
var subscriptions = _subsManager.GetHandlersForEvent(eventName);
foreach (var subscription in subscriptions)
{
var handler = subscription.HandlerType;
if (handler == null)
{
continue;
}
var handlerConstructor = handler.GetConstructors(BindingFlags.Public | BindingFlags.Instance)
.OrderByDescending(c => c.GetParameters().Length).First();
var parameters = handlerConstructor.GetParameters();
var arguments = parameters.Select(p => _serviceProvider.GetService(p.ParameterType)).ToArray();
dynamic objectHandler = handlerConstructor.Invoke(arguments);
var eventType = _subsManager.GetEventTypeByName(eventName);
var concreteType = typeof(IIntegrationEventHandler <>).MakeGenericType(eventType);
await Task.Yield();
await(Task) concreteType.GetMethod("Handle").Invoke(objectHandler, new object[] { iEvent });
}
}
else
{
_logger.LogWarning("No subscription for event: {EventName}.", eventName);
}
}
