fix download race: use tempfile + BackgroundTasks, tránh Response content shorter than Content-Length

backend/app/api/listing.py

@@ -2,7 +2,7 @@ import json
 import os
 import shutil
 import uuid
-from fastapi import APIRouter, File, UploadFile, Form, HTTPException
+from fastapi import APIRouter, File, UploadFile, Form, HTTPException, BackgroundTasks
 from fastapi.responses import FileResponse
 
 from ..config import settings
@@ -414,11 +414,15 @@ def serve_file(sid: str, filename: str):
 
 
 @router.get("/download/{sid}")
-def download_all(sid: str):
+def download_all(sid: str, background_tasks: BackgroundTasks):
+    import tempfile
+    import zipfile
+
     s = _get(sid)
-    zip_path = os.path.join(s["dir"], f"listing_{sid}.zip")
+    tmp = tempfile.NamedTemporaryFile(delete=False, suffix=".zip")
+    zip_path = tmp.name
+    tmp.close()
 
-    import zipfile
     with zipfile.ZipFile(zip_path, "w", zipfile.ZIP_DEFLATED) as zf:
         for r in s.get("results") or []:
             for img in r.get("images") or []:
@@ -432,6 +436,7 @@ def download_all(sid: str):
         if os.path.exists(text_file):
             zf.write(text_file, f"listing_text_{sid}.txt")
 
+    background_tasks.add_task(os.unlink, zip_path)
     return FileResponse(zip_path, filename=f"listing_images_{sid}.zip", media_type="application/zip")