rama_core/layer/
map_request.rs

1use crate::{Context, Layer, Service};
2use rama_utils::macros::define_inner_service_accessors;
3use std::fmt;
4
5/// Composes a function *in front of* the service.
6///
7/// This adapter produces a new service that passes each value through the
8/// given function `f` before sending it to `self`.
9#[derive(Clone)]
10pub struct MapRequest<S, F> {
11    inner: S,
12    f: F,
13}
14
15impl<S, F> fmt::Debug for MapRequest<S, F>
16where
17    S: fmt::Debug,
18{
19    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
20        f.debug_struct("MapRequest")
21            .field("inner", &self.inner)
22            .field("f", &format_args!("{}", std::any::type_name::<F>()))
23            .finish()
24    }
25}
26
27impl<S, F> MapRequest<S, F> {
28    /// Creates a new [`MapRequest`] service.
29    pub const fn new(inner: S, f: F) -> Self {
30        MapRequest { inner, f }
31    }
32
33    define_inner_service_accessors!();
34}
35
36impl<S, F, State, R1, R2> Service<State, R1> for MapRequest<S, F>
37where
38    S: Service<State, R2>,
39    F: FnOnce(R1) -> R2 + Clone + Send + Sync + 'static,
40{
41    type Response = S::Response;
42    type Error = S::Error;
43
44    #[inline]
45    fn serve(
46        &self,
47        ctx: Context<State>,
48        request: R1,
49    ) -> impl Future<Output = Result<Self::Response, Self::Error>> + Send + '_ {
50        self.inner.serve(ctx, (self.f.clone())(request))
51    }
52}
53
54/// A [`Layer`] that produces [`MapRequest`] services.
55///
56/// [`Layer`]: crate::Layer
57#[derive(Clone)]
58pub struct MapRequestLayer<F> {
59    f: F,
60}
61
62impl<F> fmt::Debug for MapRequestLayer<F> {
63    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
64        f.debug_struct("MapRequestLayer")
65            .field("f", &format_args!("{}", std::any::type_name::<F>()))
66            .finish()
67    }
68}
69
70impl<F> MapRequestLayer<F> {
71    /// Creates a new [`MapRequestLayer`].
72    pub const fn new(f: F) -> Self {
73        MapRequestLayer { f }
74    }
75}
76
77impl<S, F> Layer<S> for MapRequestLayer<F>
78where
79    F: Clone,
80{
81    type Service = MapRequest<S, F>;
82
83    fn layer(&self, inner: S) -> Self::Service {
84        MapRequest {
85            f: self.f.clone(),
86            inner,
87        }
88    }
89
90    fn into_layer(self, inner: S) -> Self::Service {
91        MapRequest { f: self.f, inner }
92    }
93}
rama_core/layer/map_request.rs

rama_core/layer/
map_request.rs
