1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
use crate::{
    body::{boxed, BoxBody},
    server::NamedService,
};
use http::{Request, Response};
use hyper::Body;
use pin_project::pin_project;
use std::{
    convert::Infallible,
    fmt,
    future::Future,
    pin::Pin,
    task::{ready, Context, Poll},
};
use tower::ServiceExt;
use tower_service::Service;

/// A [`Service`] router.
#[derive(Debug, Default, Clone)]
pub struct Routes {
    router: axum::Router,
}

#[derive(Debug, Default, Clone)]
/// Allows adding new services to routes by passing a mutable reference to this builder.
pub struct RoutesBuilder {
    routes: Option<Routes>,
}

impl RoutesBuilder {
    /// Add a new service.
    pub fn add_service<S>(&mut self, svc: S) -> &mut Self
    where
        S: Service<Request<Body>, Response = Response<BoxBody>, Error = Infallible>
            + NamedService
            + Clone
            + Send
            + 'static,
        S::Future: Send + 'static,
        S::Error: Into<crate::Error> + Send,
    {
        let routes = self.routes.take().unwrap_or_default();
        self.routes.replace(routes.add_service(svc));
        self
    }

    /// Returns the routes with added services or empty [`Routes`] if no service was added
    pub fn routes(self) -> Routes {
        self.routes.unwrap_or_default()
    }
}
impl Routes {
    /// Create a new routes with `svc` already added to it.
    pub fn new<S>(svc: S) -> Self
    where
        S: Service<Request<Body>, Response = Response<BoxBody>, Error = Infallible>
            + NamedService
            + Clone
            + Send
            + 'static,
        S::Future: Send + 'static,
        S::Error: Into<crate::Error> + Send,
    {
        let router = axum::Router::new().fallback(unimplemented);
        Self { router }.add_service(svc)
    }

    /// Add a new service.
    pub fn add_service<S>(mut self, svc: S) -> Self
    where
        S: Service<Request<Body>, Response = Response<BoxBody>, Error = Infallible>
            + NamedService
            + Clone
            + Send
            + 'static,
        S::Future: Send + 'static,
        S::Error: Into<crate::Error> + Send,
    {
        let svc = svc.map_response(|res| res.map(axum::body::boxed));
        self.router = self
            .router
            .route_service(&format!("/{}/*rest", S::NAME), svc);
        self
    }

    pub(crate) fn prepare(self) -> Self {
        Self {
            // this makes axum perform update some internals of the router that improves perf
            // see https://docs.rs/axum/latest/axum/routing/struct.Router.html#a-note-about-performance
            router: self.router.with_state(()),
        }
    }

    /// Convert this `Routes` into an [`axum::Router`].
    pub fn into_router(self) -> axum::Router {
        self.router
    }
}

async fn unimplemented() -> impl axum::response::IntoResponse {
    let status = http::StatusCode::OK;
    let headers = [("grpc-status", "12"), ("content-type", "application/grpc")];
    (status, headers)
}

impl Service<Request<Body>> for Routes {
    type Response = Response<BoxBody>;
    type Error = crate::Error;
    type Future = RoutesFuture;

    #[inline]
    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        Poll::Ready(Ok(()))
    }

    fn call(&mut self, req: Request<Body>) -> Self::Future {
        RoutesFuture(self.router.call(req))
    }
}

#[pin_project]
pub struct RoutesFuture(#[pin] axum::routing::future::RouteFuture<Body, Infallible>);

impl fmt::Debug for RoutesFuture {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_tuple("RoutesFuture").finish()
    }
}

impl Future for RoutesFuture {
    type Output = Result<Response<BoxBody>, crate::Error>;

    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
        match ready!(self.project().0.poll(cx)) {
            Ok(res) => Ok(res.map(boxed)).into(),
            Err(err) => match err {},
        }
    }
}