数据库缓存新年优惠活动

import redis
import time

r = redis.Redis()

def get_data(key):
    data = r.get(key)
    if data is None:
        with r.lock("lock:" + key, blocking_timeout=2):
            data = r.get(key)
            if data is None:
                data = load_from_db(key)  # 假设这是从数据库加载数据的函数
                r.setex(key, 3600, data)  # 设置缓存过期时间
    return data

import random

def set_cache_with_random_expiry(key, value):
    expiry = 3600 + random.randint(-600, 600)  # 在1小时内随机偏移
    r.setex(key, expiry, value)

def get_data_with_bloom_filter(key):
    if not bloom_filter.exists(key):  # 假设bloom_filter是布隆过滤器实例
        return None
    data = r.get(key)
    if data is None:
        data = load_from_db(key)
        if data is None:
            r.setex(key, 60, "")  # 缓存空值，防止再次穿透
        else:
            r.setex(key, 3600, data)
    return data