1 files changed, 56 insertions, 0 deletions
diff --git a/server/src/helper/cache.rs b/server/src/helper/cache.rs
new file mode 100644
index 0000000..d4c0595
--- /dev/null
+++ b/server/src/helper/cache.rs
@@ -0,0 +1,56 @@
+/*
+    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
+    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
+    Copyright (C) 2025 metamuffin <metamuffin.org>
+*/
+
+use log::debug;
+use rocket::{
+    http::{Header, Status},
+    response::{self, Responder},
+    Request, Response,
+};
+use std::{
+    hash::{DefaultHasher, Hash, Hasher},
+    os::unix::fs::MetadataExt,
+    path::Path,
+};
+use tokio::fs::File;
+
+pub struct CacheControlFile(File, String);
+impl CacheControlFile {
+    pub async fn new_cachekey(p: &Path) -> anyhow::Result<Self> {
+        let tag = p.file_name().unwrap().to_str().unwrap().to_owned();
+        let f = File::open(p).await?;
+        Ok(Self(f, tag))
+    }
+    pub async fn new_mtime(f: File) -> Self {
+        let meta = f.metadata().await.unwrap();
+        let modified = meta.mtime();
+        let mut h = DefaultHasher::new();
+        modified.hash(&mut h);
+        let tag = format!("{:0>16x}", h.finish());
+        Self(f, tag)
+    }
+}
+impl<'r> Responder<'r, 'static> for CacheControlFile {
+    fn respond_to(self, req: &'r Request<'_>) -> response::Result<'static> {
+        let Self(file, tag) = self;
+        if req.headers().get_one("if-none-match") == Some(&tag) {
+            debug!("file cache: not modified");
+            Response::build()
+                .status(Status::NotModified)
+                .header(Header::new("cache-control", "private"))
+                .header(Header::new("etag", tag))
+                .ok()
+        } else {
+            debug!("file cache: transfer");
+            Response::build()
+                .status(Status::Ok)
+                .header(Header::new("cache-control", "private"))
+                .header(Header::new("etag", tag))
+                .streamed_body(file)
+                .ok()
+        }
+    }
+}