tower_async_http/compression/
layer.rs

1use super::{Compression, Predicate};
2use crate::compression::predicate::DefaultPredicate;
3use crate::compression::CompressionLevel;
4use crate::compression_utils::AcceptEncoding;
5use tower_async_layer::Layer;
6
7/// Compress response bodies of the underlying service.
8///
9/// This uses the `Accept-Encoding` header to pick an appropriate encoding and adds the
10/// `Content-Encoding` header to responses.
11///
12/// See the [module docs](crate::compression) for more details.
13#[derive(Clone, Debug, Default)]
14pub struct CompressionLayer<P = DefaultPredicate> {
15    accept: AcceptEncoding,
16    predicate: P,
17    quality: CompressionLevel,
18}
19
20impl<S, P> Layer<S> for CompressionLayer<P>
21where
22    P: Predicate,
23{
24    type Service = Compression<S, P>;
25
26    fn layer(&self, inner: S) -> Self::Service {
27        Compression {
28            inner,
29            accept: self.accept,
30            predicate: self.predicate.clone(),
31            quality: self.quality,
32        }
33    }
34}
35
36impl CompressionLayer {
37    /// Create a new [`CompressionLayer`]
38    pub fn new() -> Self {
39        Self::default()
40    }
41
42    /// Sets whether to enable the gzip encoding.
43    #[cfg(feature = "compression-gzip")]
44    pub fn gzip(mut self, enable: bool) -> Self {
45        self.accept.set_gzip(enable);
46        self
47    }
48
49    /// Sets whether to enable the Deflate encoding.
50    #[cfg(feature = "compression-deflate")]
51    pub fn deflate(mut self, enable: bool) -> Self {
52        self.accept.set_deflate(enable);
53        self
54    }
55
56    /// Sets whether to enable the Brotli encoding.
57    #[cfg(feature = "compression-br")]
58    pub fn br(mut self, enable: bool) -> Self {
59        self.accept.set_br(enable);
60        self
61    }
62
63    /// Sets whether to enable the Zstd encoding.
64    #[cfg(feature = "compression-zstd")]
65    pub fn zstd(mut self, enable: bool) -> Self {
66        self.accept.set_zstd(enable);
67        self
68    }
69
70    /// Sets the compression quality.
71    pub fn quality(mut self, quality: CompressionLevel) -> Self {
72        self.quality = quality;
73        self
74    }
75
76    /// Disables the gzip encoding.
77    ///
78    /// This method is available even if the `gzip` crate feature is disabled.
79    pub fn no_gzip(mut self) -> Self {
80        self.accept.set_gzip(false);
81        self
82    }
83
84    /// Disables the Deflate encoding.
85    ///
86    /// This method is available even if the `deflate` crate feature is disabled.
87    pub fn no_deflate(mut self) -> Self {
88        self.accept.set_deflate(false);
89        self
90    }
91
92    /// Disables the Brotli encoding.
93    ///
94    /// This method is available even if the `br` crate feature is disabled.
95    pub fn no_br(mut self) -> Self {
96        self.accept.set_br(false);
97        self
98    }
99
100    /// Disables the Zstd encoding.
101    ///
102    /// This method is available even if the `zstd` crate feature is disabled.
103    pub fn no_zstd(mut self) -> Self {
104        self.accept.set_zstd(false);
105        self
106    }
107
108    /// Replace the current compression predicate.
109    ///
110    /// See [`Compression::compress_when`] for more details.
111    pub fn compress_when<C>(self, predicate: C) -> CompressionLayer<C>
112    where
113        C: Predicate,
114    {
115        CompressionLayer {
116            accept: self.accept,
117            predicate,
118            quality: self.quality,
119        }
120    }
121}
122
123#[cfg(test)]
124mod tests {
125    use super::*;
126
127    use crate::test_helpers::Body;
128
129    use http::{header::ACCEPT_ENCODING, Request, Response};
130    use http_body_util::BodyExt;
131    use std::convert::Infallible;
132    use tokio::fs::File;
133    use tokio_util::io::ReaderStream;
134    use tower_async::{Service, ServiceBuilder};
135
136    async fn handle(_req: Request<Body>) -> Result<Response<Body>, Infallible> {
137        // Open the file.
138        let file = File::open("Cargo.toml").await.expect("file missing");
139        // Convert the file into a `Stream`.
140        let stream = ReaderStream::new(file);
141        // Convert the `Stream` into a `Body`.
142        let body = Body::from_stream(stream);
143        // Create response.
144        Ok(Response::new(body))
145    }
146
147    #[tokio::test]
148    async fn accept_encoding_configuration_works() -> Result<(), crate::BoxError> {
149        let deflate_only_layer = CompressionLayer::new()
150            .quality(CompressionLevel::Best)
151            .no_br()
152            .no_gzip();
153
154        let service = ServiceBuilder::new()
155            // Compress responses based on the `Accept-Encoding` header.
156            .layer(deflate_only_layer)
157            .service_fn(handle);
158
159        // Call the service with the deflate only layer
160        let request = Request::builder()
161            .header(ACCEPT_ENCODING, "gzip, deflate, br")
162            .body(Body::empty())?;
163
164        let response = service.call(request).await?;
165
166        assert_eq!(response.headers()["content-encoding"], "deflate");
167
168        // Read the body
169        let body = response.into_body();
170        let bytes = body.collect().await.unwrap().to_bytes();
171
172        let deflate_bytes_len = bytes.len();
173
174        let br_only_layer = CompressionLayer::new()
175            .quality(CompressionLevel::Best)
176            .no_gzip()
177            .no_deflate();
178
179        let service = ServiceBuilder::new()
180            // Compress responses based on the `Accept-Encoding` header.
181            .layer(br_only_layer)
182            .service_fn(handle);
183
184        // Call the service with the br only layer
185        let request = Request::builder()
186            .header(ACCEPT_ENCODING, "gzip, deflate, br")
187            .body(Body::empty())?;
188
189        let response = service.call(request).await?;
190
191        assert_eq!(response.headers()["content-encoding"], "br");
192
193        // Read the body
194        let body = response.into_body();
195        let bytes = body.collect().await.unwrap().to_bytes();
196
197        let br_byte_length = bytes.len();
198
199        // check the corresponding algorithms are actually used
200        // br should compresses better than deflate
201        assert!(br_byte_length < deflate_bytes_len * 9 / 10);
202
203        Ok(())
204    }
205}
tower_async_http/compression/layer.rs

tower_async_http/compression/
layer.rs
