Moved singleton metaclass in utils.py.

from cloudcontrol.node.exc import TunnelError, DRBDAllocationError, DRBDError

from cloudcontrol.node.jobs import BaseThreadedJob

from cloudcontrol.node.utils import SocketBuffer, subproc_call

from cloudcontrol.node.utils import SocketBuffer, subproc_call, Singleton

logger = logging.getLogger(__name__)

        # logger.debug('Proccessed write event')

class Meta(type):

    """DRBDAllocator metaclass used for singleton implementation."""

    def __init__(cls, name, bases, dict):

        super(Meta, cls).__init__(cls, bases, dict)

        cls._instance = None

    def __call__(cls, *args, **kwargs):

        if cls._instance is None:

            cls._instance = super(Meta, cls).__call__(*args, **kwargs)

        return cls._instance

class DRBDAllocator(object):

    """Keeps a list of allocated DRBD devices."""

    __metaclass__ = Meta

    __metaclass__ = Singleton

    RMMOD = '/sbin/rmmod'

    MODPROBE = '/sbin/modprobe'

    def is_empty(self):

        return self.current_len == 0

class Singleton(type):

    """Singleton metaclass."""

    def __init__(cls, name, bases, dict):

        super(Singleton, cls).__init__(cls, bases, dict)

        cls._instance = None

    def __call__(cls, *args, **kwargs):

        if cls._instance is None:

            cls._instance = super(Singleton, cls).__call__(*args, **kwargs)

        return cls._instance