cache car brands

selfdrive/car/interfaces.py

@@ -33,6 +33,8 @@
 TORQUE_OVERRIDE_PATH = os.path.join(BASEDIR, 'selfdrive/car/torque_data/override.toml')
 TORQUE_SUBSTITUTE_PATH = os.path.join(BASEDIR, 'selfdrive/car/torque_data/substitute.toml')
 
+CAR_BRANDS = sorted(entry.name for entry in os.scandir(BASEDIR + '/selfdrive/car') if entry.is_dir())
+
 
 class LatControlInputs(NamedTuple):
  lateral_acceleration: float
@@ -477,15 +479,13 @@ def update(self, CC: car.CarControl.Actuators, CS: car.CarState, now_nanos: int)
 }
 
 # interface-specific helpers
-
 def get_interface_attr(attr: str, combine_brands: bool = False, ignore_none: bool = False) -> dict[str | StrEnum, Any]:
  # read all the folders in selfdrive/car and return a dict where:
  # - keys are all the car models or brand names
  # - values are attr values from all car folders
  result = {}
- for car_folder in sorted([x[0] for x in os.walk(BASEDIR + '/selfdrive/car')]):
+ for brand_name in CAR_BRANDS:
  try:
- brand_name = car_folder.split('/')[-1]
  brand_values = __import__(f'openpilot.selfdrive.car.{brand_name}.{INTERFACE_ATTR_FILE.get(attr, "values")}', fromlist=[attr])
  if hasattr(brand_values, attr) or not ignore_none:
  attr_data = getattr(brand_values, attr, None)