Struct Envelope 

pub struct Envelope<S>(/* private fields */);

Type-erased mailbox item for service S: a typed message dispatch or a topic operation.

Usually constructed with Envelope::new, Envelope::new_with_result_channel, Envelope::new_subscribe_topic, or Envelope::new_publish_topic, then handled by Envelope::handle inside the service run loop.

Implementations

impl<S> Envelope<S>

pub fn new<M>(message: M) -> Self

where M: Message + Send + 'static, S: Handler<M> + Send, M::Result: Send,

Wrap a message for fire-and-forget delivery (no result sent to a caller).

pub fn new_with_result_channel<M>( message: M, result_channel: Option<Sender<M::Result>>, ) -> Self

where S: Handler<M> + Send, M: Message + Send + 'static, M::Result: Send,

Wrap a message and optionally send the handler’s return value on result_channel.

When result_channel is None, behaves like Self::new.

pub fn new_subscribe_topic<T>(topic: T, result_channel: Sender<T::Item>) -> Self

where S: Service + Send, T: Topic + RoutedTopic<S>,

Register a one-shot subscriber for a specific topic value.

pub fn new_publish_topic<T>(topic: T, item: T::Item) -> Self

where S: Service + Send, T: Topic + RoutedTopic<S>,

Publish one item to a specific topic value.

pub fn new_subscribe_all_topic<T>( topic: T, result_channel: UnboundedSender<T::Item>, ) -> Self

where S: Service + Send, T: Topic + RoutedTopic<S>,

Register a subscriber waiting for all future publications.

impl<S> Envelope<S>

where S: Service + Send,

pub async fn handle(self, svc: &mut S, ctx: &mut Context<S, S::Stream>)

Dispatch this envelope: run the message handler or apply the topic subscribe/publish.