Koa 洋葱模型
2024-08-31 02:37:47
Koa 洋葱模型
let context = {
data: []
};
async function middleware1(ctx, next) {
console.log('action 001');
ctx.data.push(1);
await next();
console.log('action 006');
ctx.data.push(6);
}
async function middleware2(ctx, next) {
console.log('action 002');
ctx.data.push(2);
await next();
console.log('action 005');
ctx.data.push(5);
}
async function middleware3(ctx, next) {
console.log('action 003');
ctx.data.push(3);
await next();
console.log('action 004');
ctx.data.push(4);
}
Promise.resolve(middleware1(context, async() => {
return Promise.resolve(middleware2(context, async() => {
return Promise.resolve(middleware3(context, async() => {
return Promise.resolve();
}));
}));
}))
.then(() => {
console.log('end');
console.log('context = ', context);
});
// "action 001"
// "action 002"
// "action 003"
// "action 004"
// "action 005"
// "action 006"
// "end"
// "context = { data: [1, 2, 3, 4, 5, 6]}"
https://chenshenhai.github.io/koajs-design-note/note/chapter02/02.html
https://segmentfault.com/a/1190000013981513
https://juejin.im/post/5d28616151882539af1913d2
https://github.com/webfansplz/article/issues/10
https://www.jianshu.com/p/c76d9ffd7899
https://github.com/xixigiggling/my-ice-cream/issues/34
demo
https://github.com/mynane/sil-koa/blob/master/lib/index.js
koa server
const Koa = require("koa");
const app = new Koa();
const log = console.log;
// logger
app.use(async (ctx, next) => {
await next();
// middleware 1, 后执行
const rt = ctx.response.get("X-Response-Time");
log(`\nmiddleware 1, 后执行`, rt);
log(`${ctx.method} ${ctx.url} - ${rt}`);
});
// x-response-time
app.use(async (ctx, next) => {
const start = Date.now();
await next();
// middleware 2, 先执行
const ms = Date.now() - start;
log(`\nmiddleware 2, 先执行`, `${ms}ms`);
ctx.set("X-Response-Time", `${ms}ms`);
});
// response
app.use(async (ctx, next) => {
// log(`response ctx`, ctx);
// await next();
log(`\nmiddleware 0, 最后的 middleware 最先执行`);
ctx.body = "Hello World! <br />powered by koa.js";
});
app.listen(3000);
// app.listen(8080);
https://codesandbox.io/s/koa-server-b88bh
xgqfrms 2012-2020
www.cnblogs.com 发布文章使用：只允许注册用户才可以访问！
最新文章
- iOS 编码转换
- Linear Algebra lecture 2 note
- 用wget扒站时遇到电信劫持
- wp手机 htc x310e
- dom4j解析xml文档(增删改查)
- Java构造方法的含义和使用
- [百科] - iLBC
- 为不同浏览器创建XMLHttpRequest对象
- C语言-人狼羊菜问题-最容易看懂的解决方法及代码
- hdu 1358 period KMP入门
- Java NIO 学习笔记
- php如何计算两个时间戳之间相差的日时分秒
- cocos2d-x 颜色
- B+树概念学习
- 项目管理实践【四】Bug跟踪管理【Bug Trace and Management】
- python编程快速上手之第4章实践项目参考答案
- JAVA入门[16]-form表单，上传文件
- Spring Bean装配
- 804. Unique Morse Code Words
- Hadoop、Yarn和vcpu资源的配置