def filter(self, record):
    """Our custom record filtering logic.
    Built-in filtering logic (via logging.Filter) is too limiting.
    """
    if not self.filters:
      return True
    matched = False
    rname = record.name # shortcut
    for name in self.filters:
      if rname == name or rname.startswith(name+'.'):
        matched = True
    return matched

def _create_log_handlers(stream):
  """Create and return a default list of logging.Handler instances.
  Format WARNING messages and above to display the logging level, and
  messages strictly below WARNING not to display it.
  Args:
   stream: See the configure_logging() docstring.
  """
  # Handles logging.WARNING and above.
  error_handler = logging.StreamHandler(stream)
  error_handler.setLevel(logging.WARNING)
  formatter = logging.Formatter("%(levelname)s: %(message)s")
  error_handler.setFormatter(formatter)
 
  # Create a logging.Filter instance that only accepts messages
  # below WARNING (i.e. filters out anything WARNING or above).
  non_error_filter = logging.Filter()
  # The filter method accepts a logging.LogRecord instance.
  non_error_filter.filter = lambda record: record.levelno < logging.WARNING
 
  non_error_handler = logging.StreamHandler(stream)
  non_error_handler.addFilter(non_error_filter)
  formatter = logging.Formatter("%(message)s")
  non_error_handler.setFormatter(formatter)
 
  return [error_handler, non_error_handler]

def _default_handlers(stream):
  """Return a list of the default logging handlers to use.
  Args:
   stream: See the configure_logging() docstring.
  """
  # Create the filter.
  def should_log(record):
    """Return whether a logging.LogRecord should be logged."""
    # FIXME: Enable the logging of autoinstall messages once
    #    autoinstall is adjusted. Currently, autoinstall logs
    #    INFO messages when importing already-downloaded packages,
    #    which is too verbose.
    if record.name.startswith("webkitpy.thirdparty.autoinstall"):
      return False
    return True
 
  logging_filter = logging.Filter()
  logging_filter.filter = should_log
 
  # Create the handler.
  handler = logging.StreamHandler(stream)
  formatter = logging.Formatter("%(name)s: [%(levelname)s] %(message)s")
  handler.setFormatter(formatter)
  handler.addFilter(logging_filter)
 
  return [handler]