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Source code for kombu.utils.objects

"""Object Utilities."""

from __future__ import annotations

from threading import RLock

__all__ = ('cached_property',)

    from functools import cached_property as _cached_property
except ImportError:
    # TODO: Remove this fallback once we drop support for Python < 3.8
    from cached_property import threaded_cached_property as _cached_property

_NOT_FOUND = object()

[docs]class cached_property(_cached_property): """Implementation of Cached property.""" def __init__(self, fget=None, fset=None, fdel=None): super().__init__(fget) self.__set = fset self.__del = fdel if not hasattr(self, 'attrname'): # This is a backport so we set this ourselves. self.attrname = self.func.__name__ if not hasattr(self, 'lock'): # Prior to Python 3.12, functools.cached_property has an # undocumented lock which is required for thread-safe __set__ # and __delete__. Create one if it isn't already present. self.lock = RLock() def __get__(self, instance, owner=None): # TODO: Remove this after we drop support for Python<3.8 # or fix the signature in the cached_property package with self.lock: return super().__get__(instance, owner) def __set__(self, instance, value): if instance is None: return self with self.lock: if self.__set is not None: value = self.__set(instance, value) cache = instance.__dict__ cache[self.attrname] = value def __delete__(self, instance): if instance is None: return self with self.lock: value = instance.__dict__.pop(self.attrname, _NOT_FOUND) if self.__del and value is not _NOT_FOUND: self.__del(instance, value)
[docs] def setter(self, fset): return self.__class__(self.func, fset, self.__del)
[docs] def deleter(self, fdel): return self.__class__(self.func, self.__set, fdel)