ComfyUI/comfy_api/internal/singleton.py
2025-07-18 15:23:38 -07:00

34 lines
1.1 KiB
Python

from typing import Type, TypeVar
class SingletonMetaclass(type):
T = TypeVar("T", bound="SingletonMetaclass")
_instances = {}
def __call__(cls, *args, **kwargs):
if cls not in cls._instances:
cls._instances[cls] = super(SingletonMetaclass, cls).__call__(
*args, **kwargs
)
return cls._instances[cls]
def inject_instance(cls: Type[T], instance: T) -> None:
assert cls not in SingletonMetaclass._instances, (
"Cannot inject instance after first instantiation"
)
SingletonMetaclass._instances[cls] = instance
def get_instance(cls: Type[T], *args, **kwargs) -> T:
"""
Gets the singleton instance of the class, creating it if it doesn't exist.
"""
if cls not in SingletonMetaclass._instances:
SingletonMetaclass._instances[cls] = super(
SingletonMetaclass, cls
).__call__(*args, **kwargs)
return cls._instances[cls]
class ProxiedSingleton(object, metaclass=SingletonMetaclass):
def __init__(self):
super().__init__()