大规模音视频直播 秒杀

const express = require('express');
const app = express();
const bodyParser = require('body-parser');
const { Pool } = require('pg');

// 数据库连接池
const pool = new Pool({
  user: 'your_db_user',
  host: 'your_db_host',
  database: 'your_db_name',
  password: 'your_db_password',
  port: 5432,
});

app.use(bodyParser.json());

// 秒杀接口
app.post('/seckill', async (req, res) => {
  const { productId, userId } = req.body;

  try {
    // 开启事务
    const client = await pool.connect();
    await client.query('BEGIN');

    // 检查库存
    const stockResult = await client.query('SELECT stock FROM products WHERE id = $1 FOR UPDATE', [productId]);
    if (stockResult.rows[0].stock <= 0) {
      await client.query('ROLLBACK');
      return res.status(400).json({ message: '商品已售罄' });
    }

    // 减少库存
    await client.query('UPDATE products SET stock = stock - 1 WHERE id = $1', [productId]);

    // 记录订单
    await client.query('INSERT INTO orders (product_id, user_id) VALUES ($1, $2)', [productId, userId]);

    // 提交事务
    await client.query('COMMIT');

    res.status(200).json({ message: '秒杀成功' });
  } catch (error) {
    console.error(error);
    res.status(500).json({ message: '服务器错误' });
  }
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});