Struct Constant

pub struct Constant<T, M> { /* private fields */ }

Wraps a type so that Load::load returns a constant value.

Implementations

impl<T, M: Copy> Constant<T, M>

pub fn new(inner: T, load: M) -> Self

Wraps a T-typed service with a constant M-typed load metric.

Trait Implementations

impl<T: Debug, M: Debug> Debug for Constant<T, M>

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

Formats the value using the given formatter.

impl<D: Discover + Unpin, M: Copy> Discover for Constant<D, M>

Proxies Discover such that all changes are wrapped with a constant load.

fn poll_discover( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Result<Change<D::Key, Self::Service>, D::Error>>

Yields the next discovery change set.

type Key = <D as Discover>::Key

NewService key

type Service = Constant<<D as Discover>::Service, M>

The type of Service yielded by this Discover.

type Error = <D as Discover>::Error

Error produced during discovery

impl<T, M: Copy + PartialOrd> Load for Constant<T, M>

type Metric = M

A comparable load metric. Lesser values are “preferable” to greater values.

fn load(&self) -> M

Obtains a service’s load.

impl<S, M, Request> Service<Request> for Constant<S, M>

where S: Service<Request>, M: Copy,

type Response = <S as Service<Request>>::Response

Responses given by the service.

type Error = <S as Service<Request>>::Error

Errors produced by the service.

type Future = <S as Service<Request>>::Future

The future response value.

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

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

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

Process the request and return the response asynchronously.

impl<'pin, T, M> Unpin for Constant<T, M>

where __Constant<'pin, T, M>: Unpin,

impl<T, M> UnsafeUnpin for Constant<T, M>