漏斗限流

# coding: utf8

import time

class Funnel(object):

    def __init__(self, capacity, leaking_rate):
        self.capacity = capacity  # 漏斗容量
        self.leaking_rate = leaking_rate  # 漏嘴流水速率
        self.left_quota = capacity  # 漏斗剩余空间
        self.leaking_ts = time.time()  # 上一次漏水时间

    def make_space(self):
        now_ts = time.time()
        delta_ts = now_ts - self.leaking_ts  # 距离上一次漏水过去了多久
        delta_quota = delta_ts * self.leaking_rate  # 又可以腾出不少空间了
        if delta_quota < 1:  # 腾的空间太少，那就等下次吧
            return
        self.left_quota += delta_quota  # 增加剩余空间
        self.leaking_ts = now_ts  # 记录漏水时间
        if self.left_quota > self.capacity:  # 剩余空间不得高于容量
            self.left_quota = self.capacity

    def watering(self, quota):
        self.make_space()
        if self.left_quota >= quota:  # 判断剩余空间是否足够
            self.left_quota -= quota
            return True
        return False


funnels = {}  # 所有的漏斗

# capacity  漏斗容量
# leaking_rate 漏嘴流水速率 quota/s
def is_action_allowed(
        user_id, action_key, capacity, leaking_rate):
    key = '%s:%s' % (user_id, action_key)
    funnel = funnels.get(key)
    if not funnel:
        funnel = Funnel(capacity, leaking_rate)
        funnels[key] = funnel
    return funnel.watering(1)


for i in range(20):
    print is_action_allowed('laoqian', 'reply', 15, 0.5)

标签：capacity,self,leaking,quota,ts,rate,限流,漏斗
来源： https://blog.csdn.net/ailinyingai/article/details/114990542