在？用Node.js實(shí)現(xiàn)一個(gè)http服務(wù)器框架？

Vicky 發(fā)布于2019-08-26 14:05 / 2395人閱讀

摘要：功能演進(jìn)基礎(chǔ)服務(wù)器支持中間件支持異步中間件切換為裝飾增強(qiáng)細(xì)化統(tǒng)一異常處理細(xì)化流程控制自定義注解攔截管理注入組件標(biāo)記自動(dòng)處理返回值事務(wù)緩存框架權(quán)限認(rèn)證策略模式裝飾模式

功能演進(jìn)： V1:

基礎(chǔ)http服務(wù)器

支持中間件

支持異步中間件

V1.x:

JS切換為TS

request/response裝飾增強(qiáng)

細(xì)化統(tǒng)一異常處理

細(xì)化流程控制

V2:

AOP自定義注解攔截

IOC管理注入@Controller/@Service組件

@Request標(biāo)記handler

@ResponseBody自動(dòng)處理返回值

事務(wù)

V2.x:

緩存框架

權(quán)限認(rèn)證（AOP,策略模式,裝飾模式）

V1: SOS.js

const http = require("http");
const url = require("url");
const EventEmitter = require("events");

const compose = (ctx) => (...funcs) => {
    if (funcs.length === 0) {
        return arg => arg
    }
    let lastIndex = funcs.length - 1;
    return funcs.reduceRight((a, b, index) => b(() => {
        if (index === funcs.length - 1) {
            return Promise.resolve();
        }
        if (lastIndex !== index) {
            return Promise.reject(new Error("can not call next() over once!"))
        }
        lastIndex--;
        try {
            return Promise.resolve(a(ctx));
        } catch (e) {
            return Promise.reject(e);
        }
    }), 1);
};


const applyMiddleware = (middles, ctx) => compose(ctx)(...middles);

class SOS extends EventEmitter {
    constructor() {
        this.middleWares = [];
        this.serve = http.createServer(async (req, res) => {
            const ctx = { req, res };
            const handler = applyMiddleware(this.middleWares, ctx);
            await handler(ctx);
            res.finisn || res.end();
        });
    }

    use(mid) {
        this.middleWares.push(mid);
    }

    listen(...agr) {
        this.serve.listen(...agr);
        console.log("starting");
    }

    onerror(err, ctx) {
        if (err.code === "ENOENT") {
            ctx.status = 404;
        }
        else {
            ctx.status = 500;
        }
        let msg = err.message || "000 error";
        ctx.res.end(msg);

        this.emit("error", err);
    }
}

test.js

const sos = new SOS();
sos.listen(9009);

sos.use((next) =>async (ctx) => {
    console.log("
pathname::",url.parse(ctx.req.url).pathname);
    ctx.res.write(new Date()+"");
    console.log("before 111");
    ctx.res.write("before 111
");
    await next();
    console.log("after 111");
    ctx.res.write("after 111
");
});
sos.use((next) =>async (ctx) => {
    console.log("before 222");
    ctx.res.write("before 222
");
    await next();
    console.log("after 222");
    ctx.res.write("end test222
");
    return new Promise((resolve, reject) => {
      setTimeout(() => {
        console.log("timeout 222 ");
        ctx.res.write("timeout 222 
");
        return resolve();
      }, 3000);
    });
});
sos.use((next) =>async (ctx) => {
    console.log("before 333");
    ctx.res.write("before 333
");
    await next();
    console.log("after 333");
    ctx.res.write("end test333
");
});