Support ETag header and HEAD requests in static files

crates/static-files/src/lib.rs

@@ -24,11 +24,11 @@ use std::{
 };
 
 use axum::{
-    body::{boxed, Full},
     response::{IntoResponse, Response},
+    TypedHeader,
 };
-use headers::{ContentLength, ContentType, HeaderMapExt};
-use http::{Request, StatusCode};
+use headers::{ContentLength, ContentType, ETag, HeaderMapExt, IfNoneMatch};
+use http::{Method, Request, StatusCode};
 use rust_embed::RustEmbed;
 use tower::Service;
 
@@ -40,15 +40,49 @@ use tower::Service;
 pub struct Assets;
 
 impl Assets {
-    fn get_response(path: &str) -> Option<Response> {
+    fn get_response(
+        is_head: bool,
+        path: &str,
+        if_none_match: Option<IfNoneMatch>,
+    ) -> Option<Response> {
         let asset = Self::get(path)?;
 
+        let etag: String = asset
+            .metadata
+            .sha256_hash()
+            .iter()
+            .map(|x| format!("{:02x}", x))
+            .collect();
+        let etag: ETag = format!("\"{}\"", etag).parse().unwrap();
+
+        if let Some(if_none_match) = if_none_match {
+            if if_none_match.precondition_passes(&etag) {
+                return Some(StatusCode::NOT_MODIFIED.into_response());
+            }
+        }
+
         let len = asset.data.len().try_into().unwrap();
         let mime = mime_guess::from_path(path).first_or_octet_stream();
 
-        let mut res = Response::new(boxed(Full::from(asset.data)));
-        res.headers_mut().typed_insert(ContentType::from(mime));
-        res.headers_mut().typed_insert(ContentLength(len));
+        let res = if is_head {
+            (
+                StatusCode::OK,
+                TypedHeader(ContentType::from(mime)),
+                TypedHeader(ContentLength(len)),
+                TypedHeader(etag),
+            )
+                .into_response()
+        } else {
+            (
+                StatusCode::OK,
+                TypedHeader(ContentType::from(mime)),
+                TypedHeader(ContentLength(len)),
+                TypedHeader(etag),
+                asset.data,
+            )
+                .into_response()
+        };
+
         Some(res)
     }
 }
@@ -67,11 +101,16 @@ impl<B> Service<Request<B>> for Assets {
 
     fn call(&mut self, req: Request<B>) -> Self::Future {
         let path = req.uri().path().trim_start_matches('/');
-        // TODO: support HEAD requests
-        // TODO: support ETag
+        let if_none_match = req.headers().typed_get();
+        let is_head = match *req.method() {
+            Method::GET => false,
+            Method::HEAD => true,
+            _ => return ready(Ok(StatusCode::METHOD_NOT_ALLOWED.into_response())),
+        };
+
         // TODO: support range requests
-        let response =
-            Self::get_response(path).unwrap_or_else(|| StatusCode::NOT_FOUND.into_response());
+        let response = Self::get_response(is_head, path, if_none_match)
+            .unwrap_or_else(|| StatusCode::NOT_FOUND.into_response());
         ready(Ok(response))
     }
 }