decorators.py 文件源码

def add_event(self, loop, instance, fn):
        """
        Wraps the given function in a corutine which calls it every N seconds
        :param loop: The event loop (cls._loop)
        :param instance: The instantiated class
        :param fn: The function to be called
        :return: None
        """
        # Verify function signature
        argspec = inspect.getfullargspec(fn)
        n_args = len(argspec.args) - 1 if 'self' in argspec.args else len(argspec.args)
        n_required_args = n_args - (len(argspec.defaults) if argspec.defaults else 0)
        assert n_required_args == 0, 'Functions decorated with @Periodic cannot have any required parameters.'

        @asyncio.coroutine
        def periodic_fn():
            # If coroutine yield from else call normally
            is_coroutine = asyncio.iscoroutinefunction(fn)

            while True:
                last_exec = time.time()
                (yield from fn()) if is_coroutine else fn()
                yield from asyncio.sleep(max(0, self.time + last_exec - time.time()))

        super().add_event(loop, instance, periodic_fn())