fix: avoid holding uow during long-running file operations

Signed-off-by: Aleš Kalfas <kalfas.ales@gmail.com>

Author: aleskalfas

apps/agentstack-server/src/agentstack_server/service_layer/services/files.py

@@ -185,18 +185,19 @@ async def get_content(
         async with self._uow() as uow:
             # check if the user owns the file
             await uow.files.get(file_id=file_id, user_id=user.id, context_id=context_id)
-            async with self._object_storage.get_file(file_id=file_id) as file:
-                yield file
+
+        async with self._object_storage.get_file(file_id=file_id) as file:
+            yield file
 
     async def get_extraction(self, *, file_id: UUID, user: User, context_id: UUID | None = None) -> TextExtraction:
         async with self._uow() as uow:
             return await uow.files.get_extraction_by_file_id(file_id=file_id, user_id=user.id, context_id=context_id)
 
     async def delete(self, *, file_id: UUID, user: User, context_id: UUID | None = None) -> None:
-        async with self._uow() as uow:
-            # Collect all file IDs to delete from object storage
-            file_ids_to_delete = [file_id]
+        file_ids_to_delete = [file_id]
+        deleted = False
 
+        async with self._uow() as uow:
             # Find all extractions for this file and collect their extracted files
             try:
                 extraction = await uow.files.get_extraction_by_file_id(
@@ -209,10 +210,11 @@ async def delete(self, *, file_id: UUID, user: User, context_id: UUID | None = N
                 pass
 
             # Delete from database first (this will cascade delete extractions and extraction_files)
-            if await uow.files.delete(file_id=file_id, user_id=user.id, context_id=context_id):
-                # Then delete all related files from object storage
-                await self._object_storage.delete_files(file_ids=file_ids_to_delete)
-                await uow.commit()
+            deleted = await uow.files.delete(file_id=file_id, user_id=user.id, context_id=context_id)
+            await uow.commit()
+
+        if deleted:
+            await self._object_storage.delete_files(file_ids=file_ids_to_delete)
 
     async def _cleanup_extracted_files(self, file_ids: list[UUID]) -> None:
         """Best-effort cleanup for partially uploaded extracted files."""
@@ -282,13 +284,13 @@ async def delete_extraction(self, *, file_id: UUID, user: User, context_id: UUID
                 file_id=file_id, user_id=user.id, context_id=context_id
             )
 
-            # Delete all extracted files
-            if extraction.extracted_files:
-                file_ids_to_delete = [ef.file_id for ef in extraction.extracted_files if ef.file_id != file_id]
-                if file_ids_to_delete:
-                    await self._object_storage.delete_files(file_ids=file_ids_to_delete)
-                    for fid in file_ids_to_delete:
-                        await uow.files.delete(file_id=fid)
+        file_ids_to_delete = [ef.file_id for ef in extraction.extracted_files if ef.file_id != file_id]
+        if file_ids_to_delete:
+            await self._object_storage.delete_files(file_ids=file_ids_to_delete)
+
+        async with self._uow() as uow:
+            for fid in file_ids_to_delete:
+                await uow.files.delete(file_id=fid)
 
             await uow.files.delete_extraction(extraction_id=extraction.id)
             await uow.commit()