feat(compress): use response content type to decide compress

actix-web/src/middleware/compress.rs

@@ -1,6 +1,7 @@
 //! For middleware documentation, see [`Compress`].
 
 use std::{
+    fmt,
     future::Future,
     marker::PhantomData,
     pin::Pin,
@@ -11,14 +12,14 @@ use actix_http::encoding::Encoder;
 use actix_service::{Service, Transform};
 use actix_utils::future::{ok, Either, Ready};
 use futures_core::ready;
+use mime::Mime;
 use once_cell::sync::Lazy;
 use pin_project_lite::pin_project;
-use mime::Mime;
 
 use crate::{
     body::{EitherBody, MessageBody},
     http::{
-        header::{self, AcceptEncoding, ContentType, Encoding, HeaderValue},
+        header::{self, AcceptEncoding, ContentEncoding, Encoding, HeaderValue},
         StatusCode,
     },
     service::{ServiceRequest, ServiceResponse},
@@ -72,17 +73,22 @@ use crate::{
 /// ```
 ///
 /// [feature flags]: ../index.html#crate-features
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 #[non_exhaustive]
 pub struct Compress {
-    pub compress: fn(Mime) -> bool,
+    pub compress: fn(&HeaderValue) -> bool,
 }
 
+impl fmt::Debug for Compress {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Compress").finish()
+    }
+}
 impl Default for Compress {
     fn default() -> Self {
-	Compress {
-	    compress: |_| { true }
-	}
+        Compress {
+            compress: |_| false,
+        }
     }
 }
 
@@ -98,13 +104,16 @@ where
     type Future = Ready<Result<Self::Transform, Self::InitError>>;
 
     fn new_transform(&self, service: S) -> Self::Future {
-        ok(CompressMiddleware { service, compress: self.compress })
+        ok(CompressMiddleware {
+            service,
+            compress: self.compress,
+        })
     }
 }
 
 pub struct CompressMiddleware<S> {
     service: S,
-    compress: fn(Mime) -> bool,
+    compress: fn(&HeaderValue) -> bool,
 }
 
 impl<S, B> Service<ServiceRequest> for CompressMiddleware<S>
@@ -131,6 +140,7 @@ where
                     encoding: Encoding::identity(),
                     fut: self.service.call(req),
                     _phantom: PhantomData,
+                    compress: self.compress,
                 })
             }
 
@@ -158,6 +168,7 @@ where
                 fut: self.service.call(req),
                 encoding,
                 _phantom: PhantomData,
+                compress: self.compress,
             }),
         }
     }
@@ -172,6 +183,7 @@ pin_project! {
         fut: S::Future,
         encoding: Encoding,
         _phantom: PhantomData<B>,
+    compress: fn(&HeaderValue) -> bool,
     }
 }
 
@@ -182,8 +194,8 @@ where
 {
     type Output = Result<ServiceResponse<EitherBody<Encoder<B>>>, Error>;
 
-    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let this = self.project();
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let this = self.as_mut().project();
 
         match ready!(this.fut.poll(cx)) {
             Ok(resp) => {
@@ -195,7 +207,19 @@ where
                 };
 
                 Poll::Ready(Ok(resp.map_body(move |head, body| {
-                    EitherBody::left(Encoder::response(enc, head, body))
+                    let content_type = head.headers.get(header::CONTENT_TYPE);
+                    let should_compress = content_type
+                        .map(|value| (self.compress)(value))
+                        .unwrap_or(true);
+                    if should_compress {
+                        EitherBody::left(Encoder::response(enc, head, body))
+                    } else {
+                        EitherBody::left(Encoder::response(
+                            ContentEncoding::Identity,
+                            head,
+                            body,
+                        ))
+                    }
                 })))
             }
 
@@ -259,6 +283,7 @@ mod tests {
     use std::collections::HashSet;
 
     use super::*;
+    use crate::http::header::ContentType;
     use crate::{middleware::DefaultHeaders, test, web, App};
 
     pub fn gzip_decode(bytes: impl AsRef<[u8]>) -> Vec<u8> {
@@ -345,9 +370,9 @@ mod tests {
             App::new().wrap(Compress::default()).route(
                 "/image",
                 web::get().to(move || {
-                    let mut builder = HttpResponse::Ok();
-                    builder.body(DATA);
-                    builder.insert_header(ContentType::jpeg());
+                    let builder = HttpResponse::Ok()
+                        .insert_header(ContentType::jpeg())
+                        .body(DATA);
                     builder
                 }),
             )
@@ -357,9 +382,12 @@ mod tests {
             .uri("/image")
             .insert_header((header::ACCEPT_ENCODING, "gzip"))
             .to_request();
-	let res = test::call_service(&app, req).await;
+        let res = test::call_service(&app, req).await;
         assert_eq!(res.status(), StatusCode::OK);
-        assert_eq!(res.headers().get(header::CONTENT_TYPE).unwrap(), "gzip");
+        assert_eq!(
+            res.headers().get(header::CONTENT_TYPE).unwrap(),
+            "image/jpeg"
+        );
         let bytes = test::read_body(res).await;
         assert_eq!(bytes, DATA.as_bytes());
     }