input: 
  from typing import List, Dict, Optional
  
  class FileSystem(object):
      def __init__(self, param: Dict[str, str]):
          self.__jsub_dir = os.path.expanduser(param.get('taskDir', '~/jsub/'))
          self.__logger = logging.getLogger('JSUB')
          self.__json_format = param.get('format', 'compact')
  
      def save_task(self, data: Dict) -> None:
          """
          Saves task data to the specified directory. If the data dictionary does not 
          include an 'id' key, one will be generated and added. The task data is then 
          stored in a file within a subdirectory named after the task ID.
          >>> fs = FileSystem({'taskDir': '~/tasks/'})
          >>> fs.save_task({'name': 'task1', 'description': 'first task'})
          """
          if 'id' not in data:
              safe_mkdir(self.__jsub_dir)
              data['id'] = self.__new_task_id()
          safe_mkdir(os.path.join(self.__jsub_dir, str(data['id']), 'taskInfo'))
          task_path = os.path.join(self.__jsub_dir, str(data['id']), 'taskInfo', 'repo')
  
          data_str = self.__json_str(data)
          with open(task_path, 'a+') as f:
              fcntl.flock(f, fcntl.LOCK_EX)
              f.seek(0)
              f.truncate()
              f.write(data_str)
  
      def delete_task(self, task_id: int) -> None:
          """
          Deletes the task data for the specified task ID by removing the corresponding 
          subdirectory.
          >>> fs = FileSystem({'taskDir': '~/tasks/'})
          >>> fs.delete_task(1)
          """
          safe_rmdir(os.path.join(self.__jsub_dir, str(task_id)))
  
      def find_by_id(self, task_id: int) -> Optional[Dict]:
          """
          Finds and returns the task data for the specified task ID as a dictionary.
          >>> fs = FileSystem({'taskDir': '~/tasks/'})
          >>> fs.find_by_id(1)
          """
          return self.task_data(task_id)
  
      def find_by_ids(self, task_ids: List[int]) -> List[Dict]:
          """
          Finds and returns the task data for the specified list of task IDs as a list of 
          dictionaries.
          >>> fs = FileSystem({'taskDir': '~/tasks/'})
          >>> fs.find_by_ids([1, 2])
          """
          all_data = []
          for task_id in task_ids:
              try:
                  td = self.task_data(task_id)
                  all_data.append(td)
              except RepoReadError as e:
                  self.__logger.debug(e)
          return all_data
  
      def all_task_data(self, order: str = 'asc') -> List[Dict]:
          """
          Returns a list of all task data dictionaries, sorted by ID in ascending order 
          by default (or descending order if 'order' is set to 'desc').
          >>> fs = FileSystem({'taskDir': '~/tasks/'})
          >>> fs.all_task_data(order='desc')
          """
          task_ids = [d for d in os.listdir(self.__jsub_dir) if os.path.isdir(os.path.join(self.__jsub_dir, d))]
          task_ids.sort(key=int, reverse=(order == 'desc'))
          return self.find_by_ids(task_ids)
  
      def task_data(self, task_id: int) -> Optional[Dict]:
          """
          Returns the task data for the specified task ID as a dictionary, or None if 
          the task data is not found.
          >>> fs = FileSystem({'taskDir': '~/tasks/'})
          >>> fs.task_data(1)
          """
          safe_mkdir(os.path.join(self.__jsub_dir, str(task_id), 'taskInfo'))
          task_path = os.path.join(self.__jsub_dir, str(task_id), 'taskInfo', 'repo')
          with open(task_path, 'a+') as f:
              fcntl.flock(f, fcntl.LOCK_EX)
              f.seek(0)
              data_str = f.read()
  
          try:
              return json.loads(data_str)
          except ValueError as e:
              raise RepoReadError('JSON decode error on task %s: %s' % (task_id, e))
  
      def __new_task_id(self) -> int:
          """
          Generates a new task ID by finding the highest existing ID and incrementing it.
          """
          task_ids = [int(d) for d in os.listdir(self.__jsub_dir) if os.path.isdir(os.path.join(self.__jsub_dir, d))]
          if not task_ids:
              return 1
          task_ids.sort(key=int, reverse=True)
          return task_ids[0] + 1
  
      def __json_str(self, data: Dict) -> str:
          """
          Converts the data dictionary to a JSON string, either in compact or pretty print format.
          """
          if self.__json_format == 'pretty':
              return json.dumps(data, indent=2)
          return json.dumps(data, separators=(',', ':'))
  
output:     def update_task(self, task_id: int, new_data: Dict) -> None:
          """
          Updates the task data for the specified task ID with the new data.
          >>> fs = FileSystem({'taskDir': '~/tasks/'})
          >>> fs.update_task(1, {'name': 'updated_task1', 'description': 'updated first task'})
          """
          task_path = os.path.join(self.__jsub_dir, str(task_id), 'taskInfo', 'repo')
          with open(task_path, 'a+') as f:
              fcntl.flock(f, fcntl.LOCK_EX)
              f.seek(0)
              data_str = f.read()
              try:
                  current_data = json.loads(data_str)
              except ValueError as e:
                  raise RepoReadError('JSON decode error on task %s: %s' % (task_id, e))
              current_data.update(new_data)
              f.seek(0)
              f.truncate()
              f.write(self.__json_str(current_data))