twitter_client/
traits.rs

1//! Trait aliases for [`Future`] and [`Service`].
2
3use std::future::Future;
4use std::pin::Pin;
5use std::task::{Context, Poll};
6
7use futures_core::TryFuture;
8use http::{Request, Response};
9use http_body::Body;
10use tower_service::Service;
11
12#[cfg_attr(not(feature = "__docs"), allow(intra_doc_link_resolution_failure))]
13/// An HTTP client (like [`hyper::Client`]).
14///
15/// This is just an alias for [`tower_service::Service`] introduced to reduce the number of type
16/// parameters.
17pub trait HttpService<B>: service_private::Sealed<B> {
18    /// Body of the responses given by the service.
19    type ResponseBody: Body;
20    type Error;
21    type Future: Future<Output = Result<Response<Self::ResponseBody>, Self::Error>>;
22
23    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>>;
24
25    fn call(&mut self, request: Request<B>) -> Self::Future;
26}
27
28/// An HTTP response future.
29///
30/// This is just an alias for [`Future`] introduced to reduce the number of type parameters.
31pub trait HttpTryFuture: future_private::Sealed {
32    type Body: Body;
33    type Error;
34
35    fn try_poll(
36        self: Pin<&mut Self>,
37        cx: &mut Context<'_>,
38    ) -> Poll<Result<Response<Self::Body>, Self::Error>>;
39}
40
41impl<F, B> HttpTryFuture for F
42where
43    F: TryFuture<Ok = Response<B>>,
44    B: Body,
45{
46    type Body = B;
47    type Error = F::Error;
48
49    fn try_poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<Response<B>, F::Error>> {
50        self.try_poll(cx)
51    }
52}
53
54impl<F, B> future_private::Sealed for F
55where
56    F: TryFuture<Ok = Response<B>>,
57    B: Body,
58{
59}
60
61impl<S, ReqB, ResB> HttpService<ReqB> for S
62where
63    S: Service<Request<ReqB>, Response = Response<ResB>> + ?Sized,
64    ResB: Body,
65{
66    type ResponseBody = ResB;
67    type Error = S::Error;
68    type Future = S::Future;
69
70    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
71        Service::poll_ready(self, cx)
72    }
73
74    fn call(&mut self, request: Request<ReqB>) -> S::Future {
75        Service::call(self, request)
76    }
77}
78
79impl<S, ReqB, ResB> service_private::Sealed<ReqB> for S
80where
81    S: Service<Request<ReqB>, Response = Response<ResB>> + ?Sized,
82    ResB: Body,
83{
84}
85
86mod future_private {
87    pub trait Sealed {}
88}
89
90mod service_private {
91    pub trait Sealed<B> {}
92}
twitter_client/traits.rs

twitter_client/
traits.rs
