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, encoder};
32
33    use crate::{
34        body::{BodyStream, NONE_BODY_HINT},
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                (low, Some(up)) if low == up && low < 64 => encoding = ContentEncoding::NoOp,
57                // this variant is a crate hack. see NONE_BODY_HINT for detail.
58                NONE_BODY_HINT => encoding = ContentEncoding::NoOp,
59                _ => {}
60            }
61
62            Ok(encoder(res, encoding))
63        }
64    }
65
66    impl<S> ReadyService for CompressService<S>
67    where
68        S: ReadyService,
69    {
70        type Ready = S::Ready;
71
72        #[inline]
73        async fn ready(&self) -> Self::Ready {
74            self.0.ready().await
75        }
76    }
77}
78
79#[cfg(test)]
80mod test {
81    use xitca_unsafe_collection::futures::NowOrPanic;
82
83    use crate::{App, handler::handler_service, http::WebRequest};
84
85    use super::*;
86
87    #[test]
88    fn build() {
89        async fn noop() -> &'static str {
90            "noop"
91        }
92
93        App::new()
94            .at("/", handler_service(noop))
95            .enclosed(Compress)
96            .finish()
97            .call(())
98            .now_or_panic()
99            .unwrap()
100            .call(WebRequest::default())
101            .now_or_panic()
102            .ok()
103            .unwrap();
104    }
105}
xitca_web/middleware/compress.rs

xitca_web/middleware/
compress.rs
