pickle文件读写

class PickleNumberStorage:
    """使用Pickle二进制存储单个数值"""

    def __init__(self, filename='data.pkl', default=0):
        self.filename = filename
        self.default = default
        if not os.path.exists(filename):
            self.write(default)

    def write(self, value):
        """原子写入新值"""
        temp_file = self.filename + '.tmp'
        with open(temp_file, 'wb') as f:
            pickle.dump(value, f, protocol=pickle.HIGHEST_PROTOCOL)
        os.replace(temp_file, self.filename)  # 原子替换

    def read(self):
        """读取存储的值"""
        try:
            with open(self.filename, 'rb') as f:
                return pickle.load(f)
        except (FileNotFoundError, pickle.PickleError):
            return self.default

class MMapNumber:
    """使用内存映射高效存储单个数值（双精度浮点/长整型）"""

    def __init__(self, filename: str = 'data.bin', default: float = 0.0):
        """
        初始化内存映射文件
        :param filename: 数据文件路径
        :param default: 文件不存在时的默认值
        """
        self.filename = filename
        self.default = default
        self._init_file()

    def _init_file(self):
        """确保数据文件存在并正确初始化"""
        if not os.path.exists(self.filename):
            with open(self.filename, 'wb') as f:
                f.write(struct.pack('d', self.default))

    def write(self, value: Union[float, int]):
        """写入新值（原子操作）"""
        with open(self.filename, 'r+b') as f:
            with mmap.mmap(f.fileno(), 8) as mm:
                mm[:8] = struct.pack('d', float(value))

    def read(self) -> float:
        """读取当前值"""
        with open(self.filename, 'r+b') as f:
            with mmap.mmap(f.fileno(), 8) as mm:
                return struct.unpack('d', mm[:8])[0]

    def __enter__(self):
        """支持上下文管理器"""
        self.file_obj = open(self.filename, 'r+b')
        self.mm = mmap.mmap(self.file_obj.fileno(), 8)
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        """自动关闭资源"""
        self.mm.close()
        self.file_obj.close()

    def get_handle(self):
        """获取低级操作句柄（高级用户使用）"""
        return open(self.filename, 'r+b'), mmap.mmap(self.file_obj.fileno(), 8)