深入解析 Cloudflare Workers 技术栈：从边缘计算到分布式数据库实践

1| 平台          | 冷启动时间 | 内存限制 | 执行位置      |
2|---------------|------------|----------|---------------|
3| AWS Lambda    | 100ms+     | 3GB      | 区域级        |
4| Cloudflare Workers | <5ms      | 128MB    | 边缘节点      |
5| Vercel Edge   | 10ms       | 64MB     | 有限边缘节点  |

1addEventListener('fetch', event => {
2  event.respondWith(new Response('Edge Logic'))
3})

1// Hono 路由注册
2app.get('/user/:id', (c) => {
3  const id = c.req.param('id')
4  return c.text(id)
5})
6
7// Express 等效实现
8app.get('/user/:id', (req, res) => {
9  res.send(req.params.id)
10})

1app.use('*', async (c, next) => {
2  const auth = c.req.header('Authorization')
3  if (!validateToken(auth)) {
4    return c.text('Unauthorized', 401)
5  }
6  await next()
7  c.header('X-Response-Time', Date.now())
8})

1// 分布式锁实现库存扣减
2app.post('/order', async (c) => {
3  const db = c.env.DB
4  try {
5    await db.exec('BEGIN TRANSACTION')
6    const { rows } = await db.prepare(
7      'SELECT stock FROM products WHERE id = ? FOR UPDATE'
8    ).bind(productId).all()
9    
10    if (rows[0].stock > 0) {
11      await db.prepare(
12        'UPDATE products SET stock = stock - 1 WHERE id = ?'
13      ).bind(productId).run()
14    }
15    
16    await db.exec('COMMIT')
17    return c.json({ success: true })
18  } catch (err) {
19    await db.exec('ROLLBACK')
20    return c.json({ error: '库存不足' }, 400)
21  }
22})

1import * as Sentry from '@sentry/serverless'
2
3Sentry.GCPFunction.init({
4  dsn: '__DSN__',
5  integrations: [new Sentry.Integrations.CloudflareWorkers()]
6})
7
8app.onError((err, c) => {
9  Sentry.captureException(err)
10  return c.text('Custom Error', 500)
11})

1app.use('/api/*', async (c, next) => {
2  const signature = c.req.header('X-Signature')
3  const isValid = await verifySignature(signature, c.req.rawBody)
4  if (!isValid) return c.text('Invalid signature', 403)
5  await next()
6})

1const limiter = new TokenBucket({
2  capacity: 100,        // 令牌桶容量
3  fillRate: 10          // 每秒补充令牌数
4})
5
6app.use('/api/*', async (c, next) => {
7  const ip = c.req.headers.get('CF-Connecting-IP')
8  if (!limiter.take(ip)) {
9    return c.text('Too Many Requests', 429)
10  }
11  await next()
12})

1// 使用 Rust 编写高性能图像处理模块
2#[export]
3fn resize_image(input: &[u8], width: u32) -> Vec<u8> {
4  // 图像处理逻辑
5}

1const wasmModule = await import('./image_processor.wasm')
2const output = wasmModule.resize_image(inputBuffer, 800)

1是否需要 <100ms 的全球响应延迟？
2├── 是 → 选择 Cloudflare Workers
3│   ├── 需要关系型数据库？ → 集成 D1
4│   └── 需要高开发效率？ → 使用 Hono 框架
5└── 否 → 考虑传统 Serverless 方案