Moved singleton metaclass in utils.py.

cloudcontrol/node/hypervisor/jobs.py

@@ -14,7 +14,7 @@ import pyev
 
 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__)
@@ -573,23 +573,10 @@ class TCPTunnel(object):
         # 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'

cloudcontrol/node/utils.py

@@ -81,3 +81,16 @@ class SocketBuffer(deque):
 
     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