Load overrides once, rather than in each settings handler

jupyterlab_server/handlers.py

@@ -20,6 +20,7 @@
 from .licenses_handler import LicensesHandler, LicensesManager
 from .listings_handler import ListingsHandler, fetch_listings
 from .settings_handler import SettingsHandler
+from .settings_utils import _get_overrides
 from .themes_handler import ThemesHandler
 from .translations_handler import TranslationsHandler
 from .workspaces_handler import WorkspacesHandler, WorkspacesManager
@@ -227,11 +228,19 @@ def add_handlers(handlers: list[Any], extension_app: LabServerApp) -> None:
 
     # Handle local settings.
     if extension_app.schemas_dir:
+        # Load overrides once, rather than in each copy of the settings handler
+        overrides, error = _get_overrides(extension_app.app_settings_dir)
+
+        if error:
+            overrides_warning = "Failed loading overrides: %s"
+            extension_app.log.warning(overrides_warning, error)
+
         settings_config: dict[str, Any] = {
             "app_settings_dir": extension_app.app_settings_dir,
             "schemas_dir": extension_app.schemas_dir,
             "settings_dir": extension_app.user_settings_dir,
             "labextensions_path": labextensions_path,
+            "overrides": overrides,
         }
 
         # Handle requests for the list of settings. Make slash optional.

jupyterlab_server/settings_handler.py

@@ -25,11 +25,12 @@ def initialize(  # type:ignore[override]
         schemas_dir: str,
         settings_dir: str,
         labextensions_path: list[str],
+        overrides: dict[str, Any],
         **kwargs: Any,  # noqa: ARG002
     ) -> None:
         """Initialize the handler."""
         SchemaHandler.initialize(
-            self, app_settings_dir, schemas_dir, settings_dir, labextensions_path
+            self, app_settings_dir, schemas_dir, settings_dir, labextensions_path, overrides
         )
         ExtensionHandlerMixin.initialize(self, name)
 

jupyterlab_server/settings_utils.py

@@ -448,20 +448,17 @@ def initialize(
         schemas_dir: str,
         settings_dir: str,
         labextensions_path: list[str] | None,
+        overrides: dict[str, Any],
         **kwargs: Any,
     ) -> None:
         """Initialize the handler."""
         super().initialize(**kwargs)
-        self.overrides, error = _get_overrides(app_settings_dir)
+        self.overrides = overrides
         self.app_settings_dir = app_settings_dir
         self.schemas_dir = schemas_dir
         self.settings_dir = settings_dir
         self.labextensions_path = labextensions_path
 
-        if error:
-            overrides_warning = "Failed loading overrides: %s"
-            self.log.warning(overrides_warning, error)
-
     def get_current_locale(self) -> str:
         """
         Get the current locale as specified in the translation-extension settings.