use axum::http::{HeaderMap, StatusCode, header};
use axum::response::IntoResponse;
use std::hash::{Hash, Hasher};
pub const CACHE_STATIC_ASSET: &str = "public, max-age=31536000, immutable";
pub const CACHE_HTML: &str = "no-cache";
pub const CACHE_METADATA: &str = "public, max-age=3600";
pub fn compute_etag(content: &[u8]) -> String {
let mut hasher = std::collections::hash_map::DefaultHasher::new();
content.hash(&mut hasher);
format!("\"{}\"", hasher.finish())
}
pub(super) fn etag_matches(headers: &HeaderMap, etag: &str) -> bool {
headers
.get(header::IF_NONE_MATCH)
.and_then(|v| v.to_str().ok())
== Some(etag)
}
pub(super) fn not_modified_response(
etag: &str,
cache_control: &'static str,
) -> axum::response::Response {
(
StatusCode::NOT_MODIFIED,
[
(header::ETAG, etag.to_string()),
(header::CACHE_CONTROL, cache_control.to_string()),
],
)
.into_response()
}
fn serve_file_response(
content: Vec<u8>,
content_type: String,
cache_control: &'static str,
etag: String,
) -> axum::response::Response {
(
StatusCode::OK,
[
(header::CONTENT_TYPE, content_type),
(header::CACHE_CONTROL, cache_control.to_string()),
(header::ETAG, etag),
],
content,
)
.into_response()
}
pub(super) async fn serve_cached_file(
file_path: &std::path::Path,
headers: &HeaderMap,
content_type: &str,
cache_control: &'static str,
) -> axum::response::Response {
match tokio::fs::read(file_path).await {
Ok(content) => {
let etag = compute_etag(&content);
if etag_matches(headers, &etag) {
return not_modified_response(&etag, cache_control);
}
serve_file_response(content, content_type.to_string(), cache_control, etag)
},
Err(_) => (StatusCode::INTERNAL_SERVER_ERROR, "Error reading file").into_response(),
}
}
pub(super) fn resolve_mime_type(path: &std::path::Path) -> &'static str {
match path.extension().and_then(|ext| ext.to_str()) {
Some("js") => "application/javascript",
Some("css") => "text/css",
Some("woff" | "woff2") => "font/woff2",
Some("ttf") => "font/ttf",
Some("png") => "image/png",
Some("jpg" | "jpeg") => "image/jpeg",
Some("svg") => "image/svg+xml",
Some("ico") => "image/x-icon",
Some("json") => "application/json",
Some("pdf") => "application/pdf",
_ => "application/octet-stream",
}
}