Source code for thriftworker.utils.finalize
"""Execute cleanup handlers when objects go out of scope.
Taken from :class:`multiprocessing.util.Finalize`.
:copyright: (c) 2009 - 2012 by Ask Solem.
:license: BSD, see LICENSE for more details.
"""
from __future__ import absolute_import
from itertools import count
import weakref
__all__ = ['Finalize']
[docs]class Finalize(object):
"""Object finalization using weakrefs."""
_count = count().next
_registry = {}
def __init__(self, obj, callback, args=(), kwargs=None,
exitpriority=None):
if obj is not None:
self._weakref = weakref.ref(obj, self)
else:
assert exitpriority is not None
self._callback = callback
self._args = args
self._kwargs = kwargs or {}
self._key = (exitpriority, self._count())
self._registry[self._key] = self
def __call__(self, wr=None):
"""Run the callback unless it has already been called or
cancelled.
"""
try:
self._registry.pop(self._key)
except KeyError:
pass
else:
try:
return self._callback(*self._args, **self._kwargs)
finally:
self._reset()
def _reset(self):
self._weakref = self._callback = self._args = \
self._kwargs = self._key = None
[docs] def cancel(self):
"""Cancel finalization of the object."""
try:
self._registry.pop(self._key)
except KeyError:
pass
else:
self._reset()
[docs] def still_active(self):
return self._key in self._registry
def __repr__(self):
try:
obj = self._weakref()
except (AttributeError, TypeError):
return '<Finalize: (dead)>'
if obj is None:
return
x = '<Finalize object, callback=%s' % \
getattr(self._callback, '__name__', self._callback)
if self._args:
x += ', args=%r' % (self._args,)
if self._kwargs:
x += ', kwargs=%r' % (self._kwargs,)
if self._key[0] is not None:
x += ', exitprority=%r' % (self._key[0],)
return x + '>'