xitca_web/middleware/
compress.rs

1//! compression middleware
2
3use crate::service::Service;
4
5/// compress middleware.
6///
7/// look into [WebRequest]'s `Accept-Encoding` header and apply according compression to
8/// [WebResponse]'s body according to enabled compress feature.
9/// `compress-x` feature must be enabled for this middleware to function correctly.
10///
11/// # Type mutation
12/// `Compress` would mutate response body type from `B` to `Coder<B>`. Service enclosed
13/// by it must be able to handle it's mutation or utilize [TypeEraser] to erase the mutation.
14/// For more explanation please reference [type mutation](crate::middleware#type-mutation).
15///
16/// [WebRequest]: crate::http::WebRequest
17/// [WebResponse]: crate::http::WebResponse
18/// [TypeEraser]: crate::middleware::eraser::TypeEraser
19#[derive(Clone)]
20pub struct Compress;
21
22impl<S, E> Service<Result<S, E>> for Compress {
23    type Response = service::CompressService<S>;
24    type Error = E;
25
26    async fn call(&self, res: Result<S, E>) -> Result<Self::Response, Self::Error> {
27        res.map(service::CompressService)
28    }
29}
30mod service {
31    use http_encoding::{Coder, ContentEncoding};
32
33    use crate::{
34        body::{BodyStream, SizeHint},
35        http::{BorrowReq, WebResponse, header::HeaderMap},
36        service::{Service, ready::ReadyService},
37    };
38
39    pub struct CompressService<S>(pub(super) S);
40
41    impl<S, Req, ResB> Service<Req> for CompressService<S>
42    where
43        Req: BorrowReq<HeaderMap>,
44        S: Service<Req, Response = WebResponse<ResB>>,
45        ResB: BodyStream,
46    {
47        type Response = WebResponse<Coder<ResB>>;
48        type Error = S::Error;
49
50        async fn call(&self, req: Req) -> Result<Self::Response, Self::Error> {
51            let mut encoding = ContentEncoding::from_headers(req.borrow());
52            let res = self.0.call(req).await?;
53
54            // TODO: expose encoding filter as public api.
55            match res.body().size_hint() {
56                SizeHint::Exact(size) if size < 64 => encoding = ContentEncoding::Identity,
57                SizeHint::None => encoding = ContentEncoding::Identity,
58                _ => {}
59            }
60
61            Ok(encoding.try_encode(res))
62        }
63    }
64
65    impl<S> ReadyService for CompressService<S>
66    where
67        S: ReadyService,
68    {
69        type Ready = S::Ready;
70
71        #[inline]
72        async fn ready(&self) -> Self::Ready {
73            self.0.ready().await
74        }
75    }
76}
77
78#[cfg(test)]
79mod test {
80    use xitca_unsafe_collection::futures::NowOrPanic;
81
82    use crate::{App, handler::handler_service, http::WebRequest};
83
84    use super::*;
85
86    #[test]
87    fn build() {
88        async fn noop() -> &'static str {
89            "noop"
90        }
91
92        App::new()
93            .at("/", handler_service(noop))
94            .enclosed(Compress)
95            .finish()
96            .call(())
97            .now_or_panic()
98            .unwrap()
99            .call(WebRequest::default())
100            .now_or_panic()
101            .ok()
102            .unwrap();
103    }
104}
xitca_web/middleware/compress.rs

xitca_web/middleware/
compress.rs
