编辑 descriptors.py - 文件管理器

✏️ 编辑：descriptors.py

路径：/usr/lib64/python3.9/site-packages/setools/diff/descriptors.py

大小：1.04 KB · 修改：2023-12-07 15:49:05 · 权限：0644 · 只读（保存会失败）

# Copyright 2015, Tresys Technology, LLC
#
# SPDX-License-Identifier: LGPL-2.1-only
#
from typing import MutableMapping
from weakref import WeakKeyDictionary

class DiffResultDescriptor:

"""Descriptor for managing diff results."""

# @properties could be used instead, but there are so
    # many result attributes, this will keep the code cleaner.

def __init__(self, diff_function: str) -> None:
        self.diff_function = diff_function

# use weak references so instances can be
        # garbage collected, rather than unnecessarily
        # kept around due to this descriptor.
        self.instances: MutableMapping = WeakKeyDictionary()

def __get__(self, obj, objtype=None):
        if obj is None:
            return self

if self.instances.setdefault(obj, None) is None:
            diff = getattr(obj, self.diff_function)
            diff()

return self.instances[obj]

def __set__(self, obj, value):
        self.instances[obj] = value

def __delete__(self, obj):
        self.instances[obj] = None