Struct Singleton 

pub struct Singleton<M, Dst>
where
    M: Service<Dst>,
{ /* private fields */ }

Available on crate features client and client-pool only.

A singleton pool over an inner service.

The singleton wraps an inner service maker, bundling all calls to ensure only one service is created. Once made, it returns clones of the made service.

Implementations

impl<M, Target> Singleton<M, Target>

where M: Service<Target>, M::Response: Clone,

pub fn new(mk_svc: M) -> Self

Create a new singleton pool over an inner make service.

pub fn retain<F>(&mut self, predicate: F)

where F: FnMut(&mut M::Response) -> bool,

Retains the inner made service if specified by the predicate.

pub fn is_empty(&self) -> bool

Returns whether this singleton pool is empty.

If this pool has created a shared instance, or is currently in the process of creating one, this returns false.

Trait Implementations

impl<M, Target> Clone for Singleton<M, Target>

where M: Service<Target> + Clone,

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<M, Dst: Debug> Debug for Singleton<M, Dst>

where M: Service<Dst> + Debug, M::Response: Debug,

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

Formats the value using the given formatter.

impl<M, Target> Service<Target> for Singleton<M, Target>

where M: Service<Target>, M::Response: Clone, M::Error: Into<Box<dyn Error + Send + Sync>>,

type Response = Singled<<M as Service<Target>>::Response>

Responses given by the service.

type Error = SingletonError

Errors produced by the service.

type Future = SingletonFuture<<M as Service<Target>>::Future, <M as Service<Target>>::Response>

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, dst: Target) -> Self::Future

Process the request and return the response asynchronously.