def __init__(self, statefile):
    self.statefile = statefile

    try:
      state_data = self.statefile.read()
      if not state_data:
        self._data = {}
      else:
        self._data = serializer.Load(state_data)
    except Exception, msg: # pylint: disable=W0703
      # Ignore errors while loading the file and treat it as empty
      self._data = {}
      logging.warning(("Invalid state file. Using defaults."
                       " Error message: %s"), msg)

    if "instance" not in self._data:
      self._data["instance"] = {}
    if "node" not in self._data:
      self._data["node"] = {}

    self._orig_data = serializer.Dump(self._data)
Open, lock, read and parse the file.
dataset/ETHPy150Open ganeti/ganeti/lib/watcher/state.py/WatcherState.__init__