1use std::error::Error as StdError;
2
3use crate::body::HttpBody;
4use crate::common::{task, Future, Poll};
5use crate::{Request, Response};
6
7/// An asynchronous function from `Request` to `Response`.
8pub trait HttpService<ReqBody>: sealed::Sealed<ReqBody> {
9 /// The `HttpBody` body of the `http::Response`.
10 type ResBody: HttpBody;
11
12 /// The error type that can occur within this `Service`.
13 ///
14 /// Note: Returning an `Error` to a hyper server will cause the connection
15 /// to be abruptly aborted. In most cases, it is better to return a `Response`
16 /// with a 4xx or 5xx status code.
17 type Error: Into<Box<dyn StdError + Send + Sync>>;
18
19 /// The `Future` returned by this `Service`.
20 type Future: Future<Output = Result<Response<Self::ResBody>, Self::Error>>;
21
22 #[doc(hidden)]
23 fn poll_ready(&mut self, cx: &mut task::Context<'_>) -> Poll<Result<(), Self::Error>>;
24
25 #[doc(hidden)]
26 fn call(&mut self, req: Request<ReqBody>) -> Self::Future;
27}
28
29impl<T, B1, B2> HttpService<B1> for T
30where
31 T: tower_service::Service<Request<B1>, Response = Response<B2>>,
32 B2: HttpBody,
33 T::Error: Into<Box<dyn StdError + Send + Sync>>,
34{
35 type ResBody = B2;
36
37 type Error = T::Error;
38 type Future = T::Future;
39
40 fn poll_ready(&mut self, cx: &mut task::Context<'_>) -> Poll<Result<(), Self::Error>> {
41 tower_service::Service::poll_ready(self, cx)
42 }
43
44 fn call(&mut self, req: Request<B1>) -> Self::Future {
45 tower_service::Service::call(self, req)
46 }
47}
48
49impl<T, B1, B2> sealed::Sealed<B1> for T
50where
51 T: tower_service::Service<Request<B1>, Response = Response<B2>>,
52 B2: HttpBody,
53{
54}
55
56mod sealed {
57 pub trait Sealed<T> {}
58}
59