class CacheLastSync(object):

    def __init__(self, save_to:typing.Optional[str]=None):
        prefix = tempfile.gettempdir()
        if not save_to:
            save_to = os.path.join(prefix, fn + ".last_sync_ts")
        self.save_to = save_to

    def get(self) -> int:

        if os.path.exists(self.save_to):
            with open(self.save_to) as f:
                try:
                    return int(f.read().strip())
                except:
                    msg = "parse last_sync_ts failed"
                    logger.exception(msg)
        return -1

    def set(self, value:typing.Optional[int]=None):
        if not value:
            value = str(int(time.time()))
        with open(self.save_to, "w") as f:
            f.write(str(value))



    value = CacheLastSync().get()
    if value > 0:
        data_get["since"] = value*1000


    CacheLastSync().set(value=now)