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Source code for mmengine.registry.default_scope

# Copyright (c) OpenMMLab. All rights reserved.
import copy
import time
from contextlib import contextmanager
from typing import Generator, Optional

from mmengine.utils.manager import ManagerMixin, _accquire_lock, _release_lock


[docs]class DefaultScope(ManagerMixin): """Scope of current task used to reset the current registry, which can be accessed globally. Consider the case of resetting the current ``Registry`` by ``default_scope`` in the internal module which cannot access runner directly, it is difficult to get the ``default_scope`` defined in ``Runner``. However, if ``Runner`` created ``DefaultScope`` instance by given ``default_scope``, the internal module can get ``default_scope`` by ``DefaultScope.get_current_instance`` everywhere. Args: name (str): Name of default scope for global access. scope_name (str): Scope of current task. Examples: >>> from mmengine.model import MODELS >>> # Define default scope in runner. >>> DefaultScope.get_instance('task', scope_name='mmdet') >>> # Get default scope globally. >>> scope_name = DefaultScope.get_instance('task').scope_name """ def __init__(self, name: str, scope_name: str): super().__init__(name) assert isinstance( scope_name, str), (f'scope_name should be a string, but got {scope_name}') self._scope_name = scope_name @property def scope_name(self) -> str: """ Returns: str: Get current scope. """ return self._scope_name
[docs] @classmethod def get_current_instance(cls) -> Optional['DefaultScope']: """Get latest created default scope. Since default_scope is an optional argument for ``Registry.build``. ``get_current_instance`` should return ``None`` if there is no ``DefaultScope`` created. Examples: >>> default_scope = DefaultScope.get_current_instance() >>> # There is no `DefaultScope` created yet, >>> # `get_current_instance` return `None`. >>> default_scope = DefaultScope.get_instance( >>> 'instance_name', scope_name='mmengine') >>> default_scope.scope_name mmengine >>> default_scope = DefaultScope.get_current_instance() >>> default_scope.scope_name mmengine Returns: Optional[DefaultScope]: Return None If there has not been ``DefaultScope`` instance created yet, otherwise return the latest created DefaultScope instance. """ _accquire_lock() if cls._instance_dict: instance = super().get_current_instance() else: instance = None _release_lock() return instance
[docs] @classmethod @contextmanager def overwrite_default_scope(cls, scope_name: Optional[str]) -> Generator: """Overwrite the current default scope with `scope_name`""" if scope_name is None: yield else: tmp = copy.deepcopy(cls._instance_dict) # To avoid create an instance with the same name. time.sleep(1e-6) cls.get_instance(f'overwrite-{time.time()}', scope_name=scope_name) try: yield finally: cls._instance_dict = tmp