参考：

• https://github.com/elecrabbit/front-end-interview/blob/master/docs/guide/http.md
• https://github.com/elecrabbit/front-end-interview/blob/master/docs/guide/tcp.md
• https://github.com/elecrabbit/front-end-interview/blob/master/docs/guide/httpWritten.md
• https://github.com/elecrabbit/front-end-interview/blob/master/docs/guide/algorithm.md