gistfile1.txt

def checkQuota(method):                                                          
    @defer.inlineCallbacks                                                       
    @functools.wraps(method)                                                     
    def wrapper(self, *args, **kwargs):                                          
        key = "ip:%s" % self.request.remote_ip                                   
                                                                                 
        try:                                                                     
            n = yield self.redis.incr(key)                                       
        except Exception, e:                                                     
            log.msg("Redis failed to incr('%s'): %s" % (key, str(e)))            
            raise cyclone.web.HTTPError(503)                                     
                                                                                 
        if n == 1:                                                               
            try:                                                                 
                yield self.redis.expire(key, self.settings.expire)               
            except Exception, e:                                                 
                log.msg("Redis failed to expire('%s', %d): %s" % \               
                    (key, self.settings.expire, str(e)))                         
                raise cyclone.web.HTTPError(503)                                 
                                                                                 
        elif n > self.settings.max_requests:                                     
            # Over quota, take this.                                             
            raise cyclone.web.HTTPError(403) # Forbidden                         
                                                                                 
        yield defer.maybeDeferred(method, self, *args, **kwargs)                 
        defer.returnValue(None)                                                  
    return wrapper