From b2a7787e45c0fa092ff9481cbe5247061c626b7f Mon Sep 17 00:00:00 2001
From: stefiosif <si.iosifidis@gmail.com>
Date: Sun, 7 Jun 2026 19:53:19 +0300
Subject: [PATCH] feat(backend): serve video with HTTP range requests

---
 backend/src/model.rs                          | 19 ++++++++
 backend/src/web/routes_file.rs                | 47 ++++++++++++++++++-
 .../src/lib/components/FilePreview.svelte     |  2 +-
 3 files changed, 65 insertions(+), 3 deletions(-)

diff --git a/backend/src/model.rs b/backend/src/model.rs
index b617217..597f49c 100644
--- a/backend/src/model.rs
+++ b/backend/src/model.rs
@@ -120,6 +120,25 @@ impl FileRepository {
         Ok(stream)
     }
 
+    pub async fn stream_part(
+        &self,
+        file_id: i64,
+        user_id: i64,
+        from: u64,
+        to: u64,
+    ) -> Result<impl Stream<Item = std::io::Result<Bytes>> + use<>, LoftError> {
+        info!(
+            "Fetching metadata of file \"{}\" from file_records",
+            file_id
+        );
+        let record = self.get_file(file_id, user_id).await?;
+        info!("Streaming chunk of file \"{}\"", file_id);
+        let reader = self.op.reader(&record.storage_key).await.unwrap();
+        let stream = reader.into_bytes_stream(from..to).await.unwrap();
+
+        Ok(stream)
+    }
+
     pub async fn get_file(&self, file_id: i64, user_id: i64) -> Result<FileRecord, LoftError> {
         info!(
             "Fetching metadata of file \"{}\" from file_records",
diff --git a/backend/src/web/routes_file.rs b/backend/src/web/routes_file.rs
index 7c11231..31f2de4 100644
--- a/backend/src/web/routes_file.rs
+++ b/backend/src/web/routes_file.rs
@@ -2,6 +2,7 @@ use axum::{
     Json, Router,
     body::Body,
     extract::{Multipart, Path, State},
+    http::{HeaderMap, Response, StatusCode, header},
     response::IntoResponse,
     routing::get,
 };
@@ -19,6 +20,7 @@ pub fn routes_file(file_repository: FileRepository) -> Router {
         .route("/files", get(list_files).post(upload_file))
         .route("/files/{id}", get(get_file).delete(delete_file))
         .route("/files/{id}/download", get(download_file))
+        .route("/files/{id}/stream_part", get(stream_part))
         .with_state(file_repository)
 }
 
@@ -54,7 +56,6 @@ async fn upload_file(
     Err(LoftError::UndefinedErrorType)
 }
 
-#[axum::debug_handler]
 async fn get_file(
     State(file_repository): State<FileRepository>,
     ctx: Ctx,
@@ -66,7 +67,6 @@ async fn get_file(
     Ok(Json(record))
 }
 
-#[axum::debug_handler]
 async fn download_file(
     State(file_repository): State<FileRepository>,
     ctx: Ctx,
@@ -78,6 +78,49 @@ async fn download_file(
     Ok(Body::from_stream(stream))
 }
 
+async fn stream_part(
+    State(file_repository): State<FileRepository>,
+    ctx: Ctx,
+    headers: HeaderMap,
+    Path(file_id): Path<u64>,
+) -> Result<impl IntoResponse, LoftError> {
+    info!("stream_part");
+    let file_record = file_repository
+        .get_file(file_id as i64, ctx.user_id())
+        .await?;
+    let file_size = file_record.size as u64;
+    let (start, end): (u64, u64) = parse_range(&headers, file_size);
+
+    let stream = file_repository
+        .stream_part(file_id as i64, ctx.user_id(), start, end + 1)
+        .await?;
+
+    let respones = Response::builder()
+        .status(StatusCode::PARTIAL_CONTENT)
+        .header(header::CONTENT_TYPE, file_record.file_type)
+        .header(header::CONTENT_LENGTH, end - start + 1)
+        .header(
+            header::CONTENT_RANGE,
+            format!("bytes {start}-{end}/{file_size}"),
+        )
+        .header(header::ACCEPT_RANGES, "bytes")
+        .body(Body::from_stream(stream))
+        .unwrap();
+
+    Ok(respones)
+}
+
+fn parse_range(headers: &HeaderMap, file_size: u64) -> (u64, u64) {
+    let range = headers.get(header::RANGE);
+    let str = range.unwrap().to_str().unwrap();
+    let strip = str.strip_prefix("bytes=").unwrap();
+    let tuple = strip.split_once("-").unwrap();
+    let start = tuple.0.parse::<u64>().unwrap();
+    let end = tuple.1.parse::<u64>().unwrap_or(file_size - 1);
+
+    (start, end)
+}
+
 async fn delete_file(
     State(file_repository): State<FileRepository>,
     ctx: Ctx,
diff --git a/frontend/src/lib/components/FilePreview.svelte b/frontend/src/lib/components/FilePreview.svelte
index 6541743..aead4a7 100644
--- a/frontend/src/lib/components/FilePreview.svelte
+++ b/frontend/src/lib/components/FilePreview.svelte
@@ -25,7 +25,7 @@
         onclick={(e) => e.stopPropagation()}
     >
         {#if isVideo}
-            <VideoPreview src={`/api/files/${file.id}/download`} />
+            <VideoPreview src={`/api/files/${file.id}/stream_part`} />
             <div
                 class="pointer-events-none absolute inset-x-0 top-0 z-10 flex items-center justify-between bg-linear-to-b from-black/70 to-transparent px-4 py-3"
             >