inotify_file_watcher.py 文件源码

def _add_watch_for_path(self, path):
    # Must be called with _inotify_fd_lock held.
    logging.debug('_add_watch_for_path(%r)', path)

    for dirpath, directories, _ in itertools.chain(
        [(os.path.dirname(path), [os.path.basename(path)], None)],
        os.walk(path, topdown=True, followlinks=True)):
      watcher_common.skip_ignored_dirs(directories)
      # TODO: this is not an ideal solution as there are other ways for
      # symlinks to confuse our algorithm but a general solution is going to
      # be very complex and this is good enough to solve the immediate problem
      # with Dart's directory structure.
      watcher_common.skip_local_symlinks(
          self._real_directories, dirpath, directories)
      for directory in directories:
        directory_path = os.path.join(dirpath, directory)
        # dirpath cannot be used as the parent directory path because it is the
        # empty string for symlinks :-(
        parent_path = os.path.dirname(directory_path)

        watch_descriptor = _libc.inotify_add_watch(
            self._inotify_fd,
            ctypes.create_string_buffer(directory_path),
            _INTERESTING_INOTIFY_EVENTS)
        if watch_descriptor < 0:
          if ctypes.get_errno() == errno.ENOSPC:
            logging.warning(
                'There are too many directories in your application for '
                'changes in all of them to be monitored. You may have to '
                'restart the development server to see some changes to your '
                'files.')
            return
          error = OSError('could not add watch for %r' % directory_path)
          error.errno = ctypes.get_errno()
          error.strerror = errno.errorcode[ctypes.get_errno()]
          error.filename = directory_path
          raise error

        if parent_path in self._directory_to_subdirs:
          self._directory_to_subdirs[parent_path].add(directory_path)
        self._watch_to_directory[watch_descriptor] = directory_path
        self._directory_to_watch_descriptor[directory_path] = watch_descriptor
        self._directory_to_subdirs[directory_path] = set()