use core::{
future::Future,
marker::PhantomData,
pin::Pin,
task::{Context, Poll},
};
use pin_project_lite::pin_project;
use super::ServiceFactory;
pub struct MapInitErr<A, F, Req, Err> {
a: A,
f: F,
e: PhantomData<fn(Req) -> Err>,
}
impl<A, F, Req, Err> MapInitErr<A, F, Req, Err>
where
A: ServiceFactory<Req>,
F: Fn(A::InitError) -> Err,
{
pub(crate) fn new(a: A, f: F) -> Self {
Self {
a,
f,
e: PhantomData,
}
}
}
impl<A, F, Req, E> Clone for MapInitErr<A, F, Req, E>
where
A: Clone,
F: Clone,
{
fn clone(&self) -> Self {
Self {
a: self.a.clone(),
f: self.f.clone(),
e: PhantomData,
}
}
}
impl<A, F, Req, E> ServiceFactory<Req> for MapInitErr<A, F, Req, E>
where
A: ServiceFactory<Req>,
F: Fn(A::InitError) -> E + Clone,
{
type Response = A::Response;
type Error = A::Error;
type Config = A::Config;
type Service = A::Service;
type InitError = E;
type Future = MapInitErrFuture<A, F, Req, E>;
fn new_service(&self, cfg: A::Config) -> Self::Future {
MapInitErrFuture::new(self.a.new_service(cfg), self.f.clone())
}
}
pin_project! {
pub struct MapInitErrFuture<A, F, Req, E>
where
A: ServiceFactory<Req>,
F: Fn(A::InitError) -> E,
{
f: F,
#[pin]
fut: A::Future,
}
}
impl<A, F, Req, E> MapInitErrFuture<A, F, Req, E>
where
A: ServiceFactory<Req>,
F: Fn(A::InitError) -> E,
{
fn new(fut: A::Future, f: F) -> Self {
MapInitErrFuture { f, fut }
}
}
impl<A, F, Req, E> Future for MapInitErrFuture<A, F, Req, E>
where
A: ServiceFactory<Req>,
F: Fn(A::InitError) -> E,
{
type Output = Result<A::Service, E>;
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
let this = self.project();
this.fut.poll(cx).map_err(this.f)
}
}