mirror of
https://git.selfprivacy.org/SelfPrivacy/selfprivacy-rest-api.git
synced 2024-11-09 04:43:10 +00:00
24 lines
621 B
Python
24 lines
621 B
Python
|
"""
|
||
|
|
Singleton is a creational design pattern, which ensures that only
|
||
|
|
one object of its kind exists and provides a single point of access
|
||
|
|
to it for any other code.
|
||
|
|
"""
|
||
|
|
from threading import Lock
|
||
|
|
|
||
|
|
|
||
|
|
class SingletonMetaclass(type):
|
||
|
|
"""
|
||
|
|
This is a thread-safe implementation of Singleton.
|
||
|
|
"""
|
||
|
|
|
||
|
|
_instances = {}
|
||
|
|
_lock: Lock = Lock()
|
||
|
|
|
||
|
|
def __call__(cls, *args, **kwargs):
|
||
|
|
with cls._lock:
|
||
|
|
if cls not in cls._instances:
|
||
|
|
cls._instances[cls] = super(SingletonMetaclass, cls).__call__(
|
||
|
|
*args, **kwargs
|
||
|
|
)
|
||
|
|
return cls._instances[cls]
|