Source code
Revision control
Copy as Markdown
Other Tools
use std::future::Future;
use std::pin::Pin;
use std::task::{Context, Poll};
use futures_util::{ready, TryFuture};
use pin_project::pin_project;
use super::{Filter, FilterBase, Internal};
use crate::generic::Either;
use crate::reject::CombineRejection;
use crate::route;
type Combined<E1, E2> = <E1 as CombineRejection<E2>>::Combined;
#[derive(Clone, Copy, Debug)]
pub struct Or<T, U> {
pub(super) first: T,
pub(super) second: U,
}
impl<T, U> FilterBase for Or<T, U>
where
T: Filter,
U: Filter + Clone + Send,
U::Error: CombineRejection<T::Error>,
{
type Extract = (Either<T::Extract, U::Extract>,);
//type Error = <U::Error as CombineRejection<T::Error>>::Combined;
type Error = Combined<U::Error, T::Error>;
type Future = EitherFuture<T, U>;
fn filter(&self, _: Internal) -> Self::Future {
let idx = route::with(|route| route.matched_path_index());
EitherFuture {
state: State::First(self.first.filter(Internal), self.second.clone()),
original_path_index: PathIndex(idx),
}
}
}
#[allow(missing_debug_implementations)]
#[pin_project]
pub struct EitherFuture<T: Filter, U: Filter> {
#[pin]
state: State<T, U>,
original_path_index: PathIndex,
}
#[pin_project(project = StateProj)]
enum State<T: Filter, U: Filter> {
First(#[pin] T::Future, U),
Second(Option<T::Error>, #[pin] U::Future),
Done,
}
#[derive(Copy, Clone)]
struct PathIndex(usize);
impl PathIndex {
fn reset_path(&self) {
route::with(|route| route.reset_matched_path_index(self.0));
}
}
impl<T, U> Future for EitherFuture<T, U>
where
T: Filter,
U: Filter,
U::Error: CombineRejection<T::Error>,
{
type Output = Result<(Either<T::Extract, U::Extract>,), Combined<U::Error, T::Error>>;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
loop {
let pin = self.as_mut().project();
let (err1, fut2) = match pin.state.project() {
StateProj::First(first, second) => match ready!(first.try_poll(cx)) {
Ok(ex1) => {
return Poll::Ready(Ok((Either::A(ex1),)));
}
Err(e) => {
pin.original_path_index.reset_path();
(e, second.filter(Internal))
}
},
StateProj::Second(err1, second) => {
let ex2 = match ready!(second.try_poll(cx)) {
Ok(ex2) => Ok((Either::B(ex2),)),
Err(e) => {
pin.original_path_index.reset_path();
let err1 = err1.take().expect("polled after complete");
Err(e.combine(err1))
}
};
self.set(EitherFuture {
state: State::Done,
..*self
});
return Poll::Ready(ex2);
}
StateProj::Done => panic!("polled after complete"),
};
self.set(EitherFuture {
state: State::Second(Some(err1), fut2),
..*self
});
}
}
}