Fix LocalFileDescriptorStore mutation persistence

Previously, `LocalFileDescriptorStore` (and `LocalFileIdentifiableStore`
in the same iteration) had two compounding bugs: `get_item()` always
re-read from disk even on a cache hit, and mutations were never written
back to disk at all — so any change to a retrieved descriptor was lost
once its cache entry was evicted.

This change mirrors the fix already applied to `LocalFileIdentifiableStore`
(SDK) and `repository.py`:

- `get_descriptor_by_hash()` / `get_identifiable_by_hash()`: check the
  cache before inserting a freshly-deserialized object, so `__iter__`
  returns the same instance already in use rather than a new one.
- `get_item()` in `LocalFileDescriptorStore`: return the cached object
  directly on a hit without going to disk.
- Add `LocalFileDescriptorStore.commit()` to write the current in-memory
  state of a descriptor back to its file.
- `registry.py`: replace all `descriptor.commit()` / `aas_descriptor.commit()`
  / `submodel_descriptor.commit()` calls (which were no-ops on the model
  object) with `self.object_store.commit(x)`.

Author: s-heppner

sdk/basyx/aas/backend/local_file.py

@@ -75,6 +75,8 @@ def get_identifiable_by_hash(self, hash_: str) -> model.Identifiable:
         except FileNotFoundError as e:
             raise KeyError("No Identifiable with hash {} found in local file database".format(hash_)) from e
         with self._object_cache_lock:
+            if obj.id in self._object_cache:
+                return self._object_cache[obj.id]
             self._object_cache[obj.id] = obj
         return obj
 

server/app/backend/local_file.py

@@ -67,20 +67,15 @@ def get_descriptor_by_hash(self, hash_: str) -> _DESCRIPTOR_TYPE:
 
         :raises KeyError: If the respective file could not be found
         """
-        # Try to get the correct file
         try:
             with open("{}/{}.json".format(self.directory_path, hash_), "r") as file:
                 obj = json.load(file, cls=jsonization.ServerAASFromJsonDecoder)
         except FileNotFoundError as e:
             raise KeyError("No Descriptor with hash {} found in local file database".format(hash_)) from e
-        # If we still have a local replication of that object (since it is referenced from anywhere else), update that
-        # replication and return it.
         with self._object_cache_lock:
             if obj.id in self._object_cache:
-                old_obj = self._object_cache[obj.id]
-                old_obj.update_from(obj)
-                return old_obj
-        self._object_cache[obj.id] = obj
+                return self._object_cache[obj.id]
+            self._object_cache[obj.id] = obj
         return obj
 
     def get_item(self, identifier: model.Identifier) -> _DESCRIPTOR_TYPE:
@@ -89,6 +84,9 @@ def get_item(self, identifier: model.Identifier) -> _DESCRIPTOR_TYPE:
 
         :raises KeyError: If the respective file could not be found
         """
+        with self._object_cache_lock:
+            if identifier in self._object_cache:
+                return self._object_cache[identifier]
         try:
             return self.get_descriptor_by_hash(self._transform_id(identifier))
         except KeyError as e:
@@ -113,6 +111,20 @@ def add(self, x: _DESCRIPTOR_TYPE) -> None:
             with self._object_cache_lock:
                 self._object_cache[x.id] = x
 
+    def commit(self, x: _DESCRIPTOR_TYPE) -> None:
+        """
+        Write the current in-memory state of a stored descriptor back to its file.
+
+        :param x: The descriptor to persist
+        :raises KeyError: If the descriptor is not present in the store
+        """
+        if not os.path.exists("{}/{}.json".format(self.directory_path, self._transform_id(x.id))):
+            raise KeyError("No AAS Descriptor object with id {} exists in local file database".format(x.id))
+        with open("{}/{}.json".format(self.directory_path, self._transform_id(x.id)), "w") as file:
+            serialized = json.loads(json.dumps(x, cls=jsonization.ServerAASToJsonEncoder))
+            serialized["modelType"] = DESCRIPTOR_TYPE_TO_STRING[type(x)]
+            json.dump(serialized, file, indent=4)
+
     def discard(self, x: _DESCRIPTOR_TYPE) -> None:
         """
         Delete an :class:`~app.model.descriptor.Descriptor` AAS object from the local file store

server/app/interfaces/registry.py

@@ -180,7 +180,7 @@ def post_aas_descriptor(
             self.object_store.add(descriptor)
         except KeyError as e:
             raise Conflict(f"AssetAdministrationShellDescriptor with Identifier {descriptor.id} already exists!") from e
-        descriptor.commit()
+        self.object_store.commit(descriptor)
         created_resource_url = map_adapter.build(
             self.get_aas_descriptor_by_id, {"aas_id": descriptor.id}, force_external=True
         )
@@ -202,12 +202,12 @@ def put_aas_descriptor_by_id(
                     request, server_model.AssetAdministrationShellDescriptor, is_stripped_request(request)
                 )
             )
-            descriptor.commit()
+            self.object_store.commit(descriptor)
             return response_t()
         except NotFound:
             descriptor = HTTPApiDecoder.request_body(request, server_model.AssetAdministrationShellDescriptor, False)
             self.object_store.add(descriptor)
-            descriptor.commit()
+            self.object_store.commit(descriptor)
             created_resource_url = map_adapter.build(
                 self.get_aas_descriptor_by_id, {"aas_id": descriptor.id}, force_external=True
             )
@@ -247,7 +247,7 @@ def post_submodel_descriptor_through_superpath(
         if any(sd.id == submodel_descriptor.id for sd in aas_descriptor.submodel_descriptors):
             raise Conflict(f"Submodel Descriptor with Identifier {submodel_descriptor.id} already exists!")
         aas_descriptor.submodel_descriptors.append(submodel_descriptor)
-        aas_descriptor.commit()
+        self.object_store.commit(aas_descriptor)
         created_resource_url = map_adapter.build(
             self.get_submodel_descriptor_by_id_through_superpath,
             {"aas_id": aas_descriptor.id, "submodel_id": submodel_descriptor.id},
@@ -269,14 +269,14 @@ def put_submodel_descriptor_by_id_through_superpath(
             submodel_descriptor.update_from(
                 HTTPApiDecoder.request_body(request, server_model.SubmodelDescriptor, is_stripped_request(request))
             )
-            aas_descriptor.commit()
+            self.object_store.commit(aas_descriptor)
             return response_t()
         except NotFound:
             submodel_descriptor = HTTPApiDecoder.request_body(
                 request, server_model.SubmodelDescriptor, is_stripped_request(request)
             )
             aas_descriptor.submodel_descriptors.append(submodel_descriptor)
-            aas_descriptor.commit()
+            self.object_store.commit(aas_descriptor)
             created_resource_url = map_adapter.build(
                 self.get_submodel_descriptor_by_id_through_superpath,
                 {"aas_id": aas_descriptor.id, "submodel_id": submodel_descriptor.id},
@@ -293,7 +293,7 @@ def delete_submodel_descriptor_by_id_through_superpath(
         if submodel_descriptor is None:
             raise NotFound(f"Submodel Descriptor with Identifier {submodel_id} not found in AssetAdministrationShell!")
         aas_descriptor.submodel_descriptors.remove(submodel_descriptor)
-        aas_descriptor.commit()
+        self.object_store.commit(aas_descriptor)
         return response_t()
 
     # ------ Submodel REGISTRY ROUTES -------
@@ -321,7 +321,7 @@ def post_submodel_descriptor(
             self.object_store.add(submodel_descriptor)
         except KeyError as e:
             raise Conflict(f"Submodel Descriptor with Identifier {submodel_descriptor.id} already exists!") from e
-        submodel_descriptor.commit()
+        self.object_store.commit(submodel_descriptor)
         created_resource_url = map_adapter.build(
             self.get_submodel_descriptor_by_id, {"submodel_id": submodel_descriptor.id}, force_external=True
         )
@@ -335,14 +335,14 @@ def put_submodel_descriptor_by_id(
             submodel_descriptor.update_from(
                 HTTPApiDecoder.request_body(request, server_model.SubmodelDescriptor, is_stripped_request(request))
             )
-            submodel_descriptor.commit()
+            self.object_store.commit(submodel_descriptor)
             return response_t()
         except NotFound:
             submodel_descriptor = HTTPApiDecoder.request_body(
                 request, server_model.SubmodelDescriptor, is_stripped_request(request)
             )
             self.object_store.add(submodel_descriptor)
-            submodel_descriptor.commit()
+            self.object_store.commit(submodel_descriptor)
             created_resource_url = map_adapter.build(
                 self.get_submodel_descriptor_by_id, {"submodel_id": submodel_descriptor.id}, force_external=True
             )