use std::error::Error as StdError;
use std::fmt;
use std::marker::PhantomData;
use crate::body::Payload;
use crate::common::{Future, Poll, task};
use crate::{Request, Response};
pub trait Service<ReqBody>: sealed::Sealed<ReqBody> {
type ResBody: Payload;
type Error: Into<Box<dyn StdError + Send + Sync>>;
type Future: Future<Output=Result<Response<Self::ResBody>, Self::Error>>;
fn poll_ready(&mut self, cx: &mut task::Context<'_>) -> Poll<Result<(), Self::Error>>;
fn call(&mut self, req: Request<ReqBody>) -> Self::Future;
}
impl<T, B1, B2> Service<B1> for T
where
T: tower_service::Service<Request<B1>, Response = Response<B2>>,
B2: Payload,
T::Error: Into<Box<dyn StdError + Send + Sync>>,
{
type ResBody = B2;
type Error = T::Error;
type Future = T::Future;
fn poll_ready(&mut self, cx: &mut task::Context<'_>) -> Poll<Result<(), Self::Error>> {
tower_service::Service::poll_ready(self, cx)
}
fn call(&mut self, req: Request<B1>) -> Self::Future {
tower_service::Service::call(self, req)
}
}
impl<T, B1, B2> sealed::Sealed<B1> for T
where
T: tower_service::Service<Request<B1>, Response = Response<B2>>,
B2: Payload,
{}
mod sealed {
pub trait Sealed<T> {}
}
pub fn service_fn<F, R, S>(f: F) -> ServiceFn<F, R>
where
F: FnMut(Request<R>) -> S,
S: Future,
{
ServiceFn {
f,
_req: PhantomData,
}
}
pub struct ServiceFn<F, R> {
f: F,
_req: PhantomData<fn(R)>,
}
impl<F, ReqBody, Ret, ResBody, E> tower_service::Service<crate::Request<ReqBody>> for ServiceFn<F, ReqBody>
where
F: FnMut(Request<ReqBody>) -> Ret,
ReqBody: Payload,
Ret: Future<Output=Result<Response<ResBody>, E>>,
E: Into<Box<dyn StdError + Send + Sync>>,
ResBody: Payload,
{
type Response = crate::Response<ResBody>;
type Error = E;
type Future = Ret;
fn poll_ready(&mut self, _cx: &mut task::Context<'_>) -> Poll<Result<(), Self::Error>> {
Poll::Ready(Ok(()))
}
fn call(&mut self, req: Request<ReqBody>) -> Self::Future {
(self.f)(req)
}
}
impl<F, R> fmt::Debug for ServiceFn<F, R> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("impl Service")
.finish()
}
}