'For performance, rate limiting is handled in memory (i.e., RAM).
Loads the stored rate limits in memory (5,000 records ~= 1MB RAM).'

def load(self):

    with self.lock:
        if (not self.cache):
            for r in self.execute('select    *    from    `rate`;'):
                self.cache[(r[0], r[1])] = (0, r[2], r[3], _time.time())
        self._n = len(self.cache)
