Optimize downloading

src/app/services/files_client.py

@@ -32,17 +32,22 @@ async def upload_file(content: bytes, filename: str, caption: str) -> UploadedFi
         return UploadedFile.parse_obj(response.json())
 
 
-async def download_file(chat_id: int, message_id: int) -> Optional[bytes]:
+async def download_file(
+    chat_id: int, message_id: int
+) -> Optional[tuple[httpx.Response, httpx.AsyncClient]]:
     headers = {"Authorization": env_config.FILES_SERVER_API_KEY}
 
-    async with httpx.AsyncClient(timeout=60) as client:
-        response = await client.get(
-            f"{env_config.FILES_SERVER_URL}"
-            f"/api/v1/files/download_by_message/{chat_id}/{message_id}",
-            headers=headers,
-        )
+    client = httpx.AsyncClient(timeout=60)
+    request = client.build_request(
+        "GET",
+        f"{env_config.FILES_SERVER_URL}"
+        f"/api/v1/files/download_by_message/{chat_id}/{message_id}",
+        headers=headers,
+    )
 
-        if response.status_code != 200:
-            return None
+    response = await client.send(request, stream=True)
 
-        return response.content
+    if response.status_code != 200:
+        return None
+
+    return response, client

src/app/views.py

@@ -1,8 +1,10 @@
+import asyncio
 import base64
 
 from fastapi import APIRouter, Depends, HTTPException, status, Request
+from fastapi.responses import StreamingResponse
 
-from starlette.responses import Response
+from starlette.background import BackgroundTask
 
 from arq.connections import ArqRedis
 from asyncpg import exceptions
@@ -51,25 +53,30 @@ async def download_cached_file(object_id: int, object_type: str):
 
     cache_data = cached_file.data
 
-    data = await download_file_from_cache(
-        cache_data["chat_id"], cache_data["message_id"]
+    data, filename, book = await asyncio.gather(
+        download_file_from_cache(cache_data["chat_id"], cache_data["message_id"]),
+        get_filename(object_id, object_type),
+        get_book(object_id),
     )
 
     if data is None:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND)
 
-    filename = await get_filename(object_id, object_type)
+    response, client = data
 
-    book = await get_book(object_id)
+    async def close():
+        await response.aclose()
+        await client.aclose()
 
-    return Response(
-        data,
+    return StreamingResponse(
+        response.aiter_bytes(),
         headers={
             "Content-Disposition": f"attachment; filename={filename}",
             "X-Caption-B64": base64.b64encode(get_caption(book).encode("utf-8")).decode(
                 "latin-1"
             ),
         },
+        background=BackgroundTask(close),
     )