Struct tower::util::BoxService

pub struct BoxService<T, U, E> { /* private fields */ }

A boxed Service + Send trait object.

BoxService turns a service into a trait object, allowing the response future type to be dynamic. This type requires both the service and the response future to be Send.

If you need a boxed Service that implements Clone consider using BoxCloneService.

Dynamically dispatched Service objects allow for erasing the underlying Service type and using the Service instances as opaque handles. This can be useful when the service instance cannot be explicitly named for whatever reason.

Examples

use futures_util::future::ready;
// Respond to requests using a closure, but closures cannot be named...
let svc = service_fn(|mut request: String| {
    request.push_str(" response");
    ready(Ok(request))
});

let service: BoxService<String, String, ()> = BoxService::new(svc);
}

Implementations

impl<T, U, E> BoxService<T, U, E>

pub fn new<S>(inner: S) -> Self

where S: Service<T, Response = U, Error = E> + Send + 'static, S::Future: Send + 'static,

pub fn layer<S>() -> LayerFn<fn(_: S) -> Self>

where S: Service<T, Response = U, Error = E> + Send + 'static, S::Future: Send + 'static,

Returns a Layer for wrapping a Service in a BoxService middleware.

Trait Implementations

impl<T, U, E> Debug for BoxService<T, U, E>

fn fmt(&self, fmt: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T, U, E> Service<T> for BoxService<T, U, E>

type Response = U

Responses given by the service.

type Error = E

Errors produced by the service.

type Future = Pin<Box<dyn Future<Output = Result<U, E>> + Send>>

The future response value.

fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), E>>

Returns Poll::Ready(Ok(())) when the service is able to process requests.

fn call( &mut self, request: T, ) -> Pin<Box<dyn Future<Output = Result<U, E>> + Send>>

Process the request and return the response asynchronously.