93 lines
2.3 KiB
Rust
93 lines
2.3 KiB
Rust
//! Future types
|
|
|
|
use super::error::{self, Error};
|
|
use futures_core::ready;
|
|
use pin_project::{pin_project, project};
|
|
use std::{
|
|
future::Future,
|
|
pin::Pin,
|
|
task::{Context, Poll},
|
|
};
|
|
use tower_service::Service;
|
|
|
|
/// Filtered response future
|
|
#[pin_project]
|
|
#[derive(Debug)]
|
|
pub struct ResponseFuture<T, S, Request>
|
|
where
|
|
S: Service<Request>,
|
|
{
|
|
#[pin]
|
|
/// Response future state
|
|
state: State<Request, S::Future>,
|
|
|
|
#[pin]
|
|
/// Predicate future
|
|
check: T,
|
|
|
|
/// Inner service
|
|
service: S,
|
|
}
|
|
|
|
#[pin_project]
|
|
#[derive(Debug)]
|
|
enum State<Request, U> {
|
|
Check(Option<Request>),
|
|
WaitResponse(#[pin] U),
|
|
}
|
|
|
|
impl<F, T, S, Request> ResponseFuture<F, S, Request>
|
|
where
|
|
F: Future<Output = Result<T, Error>>,
|
|
S: Service<Request>,
|
|
S::Error: Into<error::Source>,
|
|
{
|
|
pub(crate) fn new(request: Request, check: F, service: S) -> Self {
|
|
ResponseFuture {
|
|
state: State::Check(Some(request)),
|
|
check,
|
|
service,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<F, T, S, Request> Future for ResponseFuture<F, S, Request>
|
|
where
|
|
F: Future<Output = Result<T, Error>>,
|
|
S: Service<Request>,
|
|
S::Error: Into<error::Source>,
|
|
{
|
|
type Output = Result<S::Response, Error>;
|
|
|
|
#[project]
|
|
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
|
|
let mut this = self.project();
|
|
|
|
loop {
|
|
#[project]
|
|
match this.state.as_mut().project() {
|
|
State::Check(request) => {
|
|
let request = request
|
|
.take()
|
|
.expect("we either give it back or leave State::Check once we take");
|
|
|
|
// Poll predicate
|
|
match this.check.as_mut().poll(cx)? {
|
|
Poll::Ready(_) => {
|
|
let response = this.service.call(request);
|
|
this.state.set(State::WaitResponse(response));
|
|
}
|
|
Poll::Pending => {
|
|
this.state.set(State::Check(Some(request)));
|
|
return Poll::Pending;
|
|
}
|
|
}
|
|
}
|
|
State::WaitResponse(response) => {
|
|
return Poll::Ready(ready!(response.poll(cx)).map_err(Error::inner));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|