Trait hyper::service::Service

pub trait Service<Request> {
    type Response;
    type Error;
    type Future: Future<Output = Result<Self::Response, Self::Error>>;

    // Required method
    fn call(&self, req: Request) -> Self::Future;
}

An asynchronous function from a Request to a Response.

The Service trait is a simplified interface making it easy to write network applications in a modular and reusable way, decoupled from the underlying protocol.

Functional

A Service is a function of a Request. It immediately returns a Future representing the eventual completion of processing the request. The actual request processing may happen at any time in the future, on any thread or executor. The processing may depend on calling other services. At some point in the future, the processing will complete, and the Future will resolve to a response or error.

At a high level, the Service::call function represents an RPC request. The Service value can be a server or a client.

Required Associated Types

type Response

Responses given by the service.

type Error

Errors produced by the service.

type Future: Future<Output = Result<Self::Response, Self::Error>>

The future response value.

Required Methods

fn call(&self, req: Request) -> Self::Future

Process the request and return the response asynchronously. call takes &self instead of mut &self because:

• It prepares the way for async fn, since then the future only borrows &self, and thus a Service can concurrently handle multiple outstanding requests at once.
• It’s clearer that Services can likely be cloned
• To share state across clones, you generally need Arc<Mutex<_>> That means you’re not really using the &mut self and could do with a &self. The discussion on this is here: https://github.com/hyperium/hyper/issues/3040

Implementors