一个工作单元内多个消息的相同Rebus处理程序实例

Question

我希望在批处理中处理相关消息，例如使用Rebus服务总线在相同范围/事务中使用相同处理程序(相同实例)处理事件CustomerCreated和PreferredCustomer。

同一个处理程序同时处理两个消息/事件:

class CustomerHandler : IHandleMessages<CustomerCreated>, IHandleMessages<PreferredCustomer>
{
    Customer Customer { get; set; }
    public CustomerHandler() {
        Customer = new Customer();
    }
    public void Handle(CustomerCreated message) {
        Customer.Name = message.Name;
        Console.WriteLine(Customer);
    }
    public void Handle(PreferredCustomer message) {
        Customer.Rebate = message.Rebate;
        Console.WriteLine(Customer);
    }
}

发送消息时，我使用批处理操作(在NServiceBus中传输消息)

bus.Advanced.Batch.Publish(
  new CustomerCreated() { Name = "Anders" }, 
  new PreferredCustomer() { Rebate = 10 });

为了控制处理程序的生命周期，我使用了Windsor Castle的Scoped lifestyle

_container.Register(
  Component.For<IHandleMessages<CustomerCreated>, IHandleMessages<PreferredCustomer>>)
    .ImplementedBy<CustomerHandler>().LifestyleScoped());

和一个实例化ScopedUnitOfWork的自定义UnitOfWorkManager

class CustomUnitOfWorkManager : IUnitOfWorkManager
{
    private readonly IWindsorContainer _container;
    public CustomUnitOfWorkManager(IWindsorContainer container) {
        _container = container;
    }
    public IUnitOfWork Create() {
        return new ScopedUnitOfWork(_container);
    }
}
class ScopedUnitOfWork : IUnitOfWork
{
    private readonly IDisposable _scope;
    public ScopedUnitOfWork(IWindsorContainer container) {
        // Begin transaction
        _scope = container.BeginScope();
    }
    public void Dispose() {
        _scope.Dispose();
    }
    public void Commit() {
        // Commit transaction
        Console.WriteLine("Commiting");
    }
    public void Abort() {
        // Rollback transaction            
        Console.WriteLine("Aborting!!!");
    }
}

最后配置Rebus使用CustomUnitOfWorkManager

var bus = Configure.With(new WindsorContainerAdapter(_container))
  .Transport(t => t.UseMsmqAndGetInputQueueNameFromAppConfig())
  .MessageOwnership(d => d.FromRebusConfigurationSection())
  .Events(x => x.AddUnitOfWorkManager(new CustomUnitOfWorkManager(_container)))
  .CreateBus()
  .Start();

这个方法正确吗?

我有限的测试表明这应该可以工作。我甚至可以将其扩展为在ScopedUnitOfWork中包含针对数据存储的事务管理。

Answer 1

听起来你已经搞定了:)

如果你得到正确的提交/回滚行为，那么我会说它很好，很好。

如果你对另一种方法感兴趣，你可能想看看PerTransportMessage Castle Windsor作用域访问器——它可以这样使用:

container.Register(
    Component
        .For<ISomething>()
        .ImplementedBy<Whatever>()
        .LifestyleScoped<PerTransportMessage>()
);

应该能够达到完全相同的行为