大屏数据展示平台限时秒杀

import React, { useState, useEffect } from 'react';

function Countdown({ endTime }) {
  const [timeLeft, setTimeLeft] = useState(calculateTimeLeft(endTime));

  useEffect(() => {
    const timer = setTimeout(() => {
      setTimeLeft(calculateTimeLeft(endTime));
    }, 1000);

    return () => clearTimeout(timer);
  }, [endTime]);

  function calculateTimeLeft(endTime) {
    const difference = new Date(endTime).getTime() - new Date().getTime();
    if (difference <= 0) return { days: 0, hours: 0, minutes: 0, seconds: 0 };
    const days = Math.floor(difference / (1000 * 60 * 60 * 24));
    const hours = Math.floor((difference / (1000 * 60 * 60)) % 24);
    const minutes = Math.floor((difference / 1000 / 60) % 60);
    const seconds = Math.floor((difference / 1000) % 60);
    return { days, hours, minutes, seconds };
  }

  return (
    <div>
      {timeLeft.days}天 {timeLeft.hours}小时 {timeLeft.minutes}分 {timeLeft.seconds}秒
    </div>
  );
}

export default Countdown;

import redis
from datetime import datetime

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

def pre_decrease_stock(product_id, quantity):
    key = f"stock:{product_id}"
    current_stock = r.get(key)
    if current_stock and int(current_stock) >= quantity:
        r.decrby(key, quantity)
        return True
    return False

def set_end_time(product_id, end_time):
    r.set(f"end_time:{product_id}", end_time.timestamp())

# 设置秒杀结束时间
set_end_time('product123', datetime(2023, 12, 31, 23, 59, 59))

# 预减库存
if pre_decrease_stock('product123', 1):
    print("秒杀成功")
else:
    print("库存不足")