WebSockets Fun

Usage

• yarn
• Run Node Server: yarn server
• Run Node Client: yarn client
• Run Browser Client: Go to http://localhost:4000 and play with window.socket in browser

Links:

RFC | WebSockets API on MDN

Armin Ronacher | Popular Medium Article

websockets/ws | websockets/ws API

Notes

URL

ws:// for 80 and wss:// for 443.

Framing: OpCode

• 0x00: this frame continues the payload from the last.
• 0x01: this frame includes utf-8 text data.
• 0x02: this frame includes binary data.
• 0x08: this frame terminates the connection.
• 0x09: this frame is a ping.
• 0x0a: this frame is a pong.

Framing: Closing Frame

• 1000: 1000 indicates a normal closure, meaning that the purpose for which the connection was established has been fulfilled.
• 1001: 1001 indicates that an endpoint is "going away", such as a server going down or a browser having navigated away from a page.
• 1002: 1002 indicates that an endpoint is terminating the connection due to a protocol error.
• 1003: 1003 indicates that an endpoint is terminating the connection because it has received a type of data it cannot accept (e.g., an endpoint that understands only text data MAY send this if it receives a binary message).

// client
socket.close(1000, 'close')

// server
conn.on('close', (code, reason) => { })

Libraries

In Browser, use the native WebSocket object. For Server side: ws seems decent.

Ping-Pong

Usually only server sends ping and client responds with pong.

Heartbeat

https://github.com/websockets/ws#how-to-detect-and-close-broken-connections

License

MIT © Pine Wu