Synnefo » snf-ganeti

import collections

class LineSplitter:

  """Splits data chunks into lines separated by newline.

  Instances provide a file-like interface.

  """

  def __init__(self, line_fn, *args):

    """Initializes this class.

    @type line_fn: callable

    @param line_fn: Function called for each line, first parameter is line

    @param args: Extra arguments for L{line_fn}

    """

    assert callable(line_fn)

    if args:

      # Python 2.4 doesn't have functools.partial yet

      self._line_fn = \

        lambda line: line_fn(line, *args) # pylint: disable-msg=W0142

    else:

      self._line_fn = line_fn

    self._lines = collections.deque()

    self._buffer = ""

  def write(self, data):

    parts = (self._buffer + data).split("\n")

    self._buffer = parts.pop()

    self._lines.extend(parts)

  def flush(self):

    while self._lines:

      self._line_fn(self._lines.popleft().rstrip("\r\n"))

  def close(self):

    self.flush()

    if self._buffer:

      self._line_fn(self._buffer)