流计算限时秒杀

import redis
import time

r = redis.Redis(host='localhost', port=6379, db=0)

def seckill(product_id, user_id):
    stock_key = f"stock:{product_id}"
    user_key = f"user:{user_id}:purchased"

    # 使用Redis事务确保操作的原子性
    with r.pipeline() as pipe:
        while True:
            try:
                pipe.watch(stock_key)
                stock = int(pipe.get(stock_key) or 0)
                if stock <= 0:
                    return False  # 库存不足

                pipe.multi()
                pipe.decr(stock_key)  # 减少库存
                pipe.sadd(user_key, product_id)  # 记录用户购买信息
                pipe.execute()
                return True  # 秒杀成功
            except redis.WatchError:
                continue  # 重试

# 模拟秒杀请求
if __name__ == "__main__":
    start_time = time.time()
    for i in range(1000):  # 模拟1000个并发请求
        seckill("product_1", f"user_{i}")
    end_time = time.time()
    print(f"处理1000个请求耗时: {end_time - start_time}秒")