Casbin Policy Auto Reloader

loader.py

"""
Current version(1.1.7) of AsyncCasbin doesn't support any async orm adapter,
it means adapter such as casbin_tortoise_adapter wouldn't work with the SyncedEnforcer class
(you will recieve "... was never awaited" if you use it ).

So we could just use common Enforcer, and reload the policy periodically(the strategy SyncedEnforcer choose).
"""
import casbin
import casbin_tortoise_adapter

_adapter = casbin_tortoise_adapter.TortoiseAdapter()
enforcer = casbin.Enforcer(_your_model, _adapter)

class PolicyLoaderThread(threading.Thread):
    def __init__(self, interval=10):
        super(PolicyLoaderThread, self).__init__(daemon=True)
        self._interval = interval
        self._stop = threading.Event()
        self._io_loop = asyncio.get_event_loop()

    @staticmethod
    async def task():
        await enforcer.load_policy()

    def run(self):
        self._io_loop.create_task(self.task())  # loading policy at startup
        while not self.stopped:
            self._stop.wait(self._interval)
            if self.stopped:
                """
                Stopping threading when _stop was set.
                
                You could change to continue if you want to restart it. Clearing the _stop flag to restart it.
                """
                break
            self._io_loop.create_task(self.task())

    def stop(self):
        self._stop.set()
        self._io_loop.close()

    @property
    def stopped(self):
        return self._stop.is_set()

_thread = PolicyLoaderThread()
_thread.start()