static_web_server/
control_headers.rs

1// SPDX-License-Identifier: MIT OR Apache-2.0
2// This file is part of Static Web Server.
3// See https://static-web-server.net/ for more information
4// Copyright (C) 2019-present Jose Quintana <joseluisq.net>
5
6//! It provides an arbitrary `Cache-Control` headers functionality
7//! for incoming requests based on a set of file types.
8//!
9
10use hyper::{Body, Request, Response, header::HeaderValue};
11
12use crate::{Error, handler::RequestHandlerOpts};
13
14// Pre-computed static Cache-Control header values
15static CACHE_CONTROL_ONE_HOUR: HeaderValue = HeaderValue::from_static("max-age=3600");
16static CACHE_CONTROL_ONE_DAY: HeaderValue = HeaderValue::from_static("max-age=86400");
17static CACHE_CONTROL_ONE_YEAR: HeaderValue = HeaderValue::from_static("max-age=31536000");
18
19// `Cache-Control` list of extensions
20const CACHE_EXT_ONE_HOUR: [&str; 4] = ["atom", "json", "rss", "xml"];
21const CACHE_EXT_ONE_YEAR: [&str; 32] = [
22    "avif", "bmp", "bz2", "css", "doc", "gif", "gz", "htc", "ico", "jpeg", "jpg", "js", "jxl",
23    "map", "mjs", "mp3", "mp4", "ogg", "ogv", "pdf", "png", "rar", "rtf", "tar", "tgz", "wav",
24    "weba", "webm", "webp", "woff", "woff2", "zip",
25];
26
27pub(crate) fn init(enabled: bool, handler_opts: &mut RequestHandlerOpts) {
28    handler_opts.cache_control_headers = enabled;
29    tracing::info!("cache control headers: enabled={enabled}");
30}
31
32/// Appends `Cache-Control` header to a response if necessary
33pub(crate) fn post_process<T>(
34    opts: &RequestHandlerOpts,
35    req: &Request<T>,
36    mut resp: Response<Body>,
37) -> Result<Response<Body>, Error> {
38    if opts.cache_control_headers {
39        append_headers(req.uri().path(), &mut resp);
40    }
41    Ok(resp)
42}
43
44/// It appends a `Cache-Control` header to a response if that one is part of a set of file types.
45pub fn append_headers(uri: &str, resp: &mut Response<Body>) {
46    let header_value = get_cache_control_header(uri);
47    resp.headers_mut()
48        .insert("cache-control", header_value.clone());
49}
50
51/// Gets the file extension for a URI.
52///
53/// This assumes the extension contains a single dot. e.g. for "/file.tar.gz" it returns "gz".
54#[inline(always)]
55fn get_file_extension(uri: &str) -> Option<&str> {
56    uri.rsplit_once('.').map(|(_, rest)| rest)
57}
58
59/// Returns the pre-computed static Cache-Control header value for the given URI.
60#[inline(always)]
61fn get_cache_control_header(uri: &str) -> &'static HeaderValue {
62    if let Some(extension) = get_file_extension(uri) {
63        if CACHE_EXT_ONE_HOUR.binary_search(&extension).is_ok() {
64            return &CACHE_CONTROL_ONE_HOUR;
65        } else if CACHE_EXT_ONE_YEAR.binary_search(&extension).is_ok() {
66            return &CACHE_CONTROL_ONE_YEAR;
67        }
68    }
69    &CACHE_CONTROL_ONE_DAY
70}
71
72#[cfg(test)]
73mod tests {
74    use hyper::{Body, Response, StatusCode};
75
76    use super::{CACHE_EXT_ONE_HOUR, CACHE_EXT_ONE_YEAR, append_headers, get_file_extension};
77
78    #[test]
79    fn headers_one_hour() {
80        let mut resp = Response::new(Body::empty());
81        *resp.status_mut() = StatusCode::OK;
82
83        for ext in CACHE_EXT_ONE_HOUR.iter() {
84            append_headers(&["/some.", ext].concat(), &mut resp);
85
86            let cache_control = resp.headers().get(http::header::CACHE_CONTROL).unwrap();
87            assert_eq!(resp.status(), StatusCode::OK);
88            assert_eq!(cache_control.to_str().unwrap(), "max-age=3600");
89        }
90    }
91
92    #[test]
93    fn headers_one_day_default() {
94        let mut resp = Response::new(Body::empty());
95        *resp.status_mut() = StatusCode::OK;
96
97        append_headers("/", &mut resp);
98
99        let cache_control = resp.headers().get(http::header::CACHE_CONTROL).unwrap();
100        assert_eq!(resp.status(), StatusCode::OK);
101        assert_eq!(cache_control.to_str().unwrap(), "max-age=86400");
102    }
103
104    #[test]
105    fn headers_one_year() {
106        let mut resp = Response::new(Body::empty());
107        *resp.status_mut() = StatusCode::OK;
108
109        for ext in CACHE_EXT_ONE_YEAR.iter() {
110            append_headers(&["/some.", ext].concat(), &mut resp);
111
112            let cache_control = resp.headers().get(http::header::CACHE_CONTROL).unwrap();
113            assert_eq!(resp.status(), StatusCode::OK);
114            assert_eq!(cache_control.to_str().unwrap(), "max-age=31536000");
115        }
116    }
117
118    #[test]
119    fn find_uri_extension() {
120        assert_eq!(get_file_extension("/potato.zip"), Some("zip"));
121        assert_eq!(get_file_extension("/potato."), Some(""));
122        assert_eq!(get_file_extension("/"), None);
123    }
124}
static_web_server/control_headers.rs

static_web_server/
control_headers.rs
