ms/packages/websocket/src/engine.io/transports/websocket.ts

117 lines
2.7 KiB
TypeScript

import { Transport } from '../transport'
// const debug = require("debug")("engine:ws")
export class WebSocket extends Transport {
public perMessageDeflate: any
/**
* WebSocket transport
*
* @param {http.IncomingMessage}
* @api public
*/
constructor(req) {
super(req)
this.socket = req.websocket
this.socket.on("message", this.onData.bind(this))
this.socket.once("close", this.onClose.bind(this))
this.socket.on("error", this.onError.bind(this))
this.writable = true
this.perMessageDeflate = null
}
/**
* Transport name
*
* @api public
*/
get name() {
return "websocket"
}
/**
* Advertise upgrade support.
*
* @api public
*/
get handlesUpgrades() {
return true
}
/**
* Advertise framing support.
*
* @api public
*/
get supportsFraming() {
return true
}
/**
* Processes the incoming data.
*
* @param {String} encoded packet
* @api private
*/
onData(data) {
// debug('received "%s"', data)
super.onData(data)
}
/**
* Writes a packet payload.
*
* @param {Array} packets
* @api private
*/
send(packets) {
// console.log('WebSocket send packets', JSON.stringify(packets))
const packet = packets.shift()
if (typeof packet === "undefined") {
this.writable = true
this.emit("drain")
return
}
// always creates a new object since ws modifies it
const opts: any = {}
if (packet.options) {
opts.compress = packet.options.compress
}
const send = data => {
if (this.perMessageDeflate) {
const len =
"string" === typeof data ? Buffer.byteLength(data) : data.length
if (len < this.perMessageDeflate.threshold) {
opts.compress = false
}
}
console.trace('writing', data)
this.writable = false
this.socket.send(data, opts, err => {
if (err) return this.onError("write error", err.stack)
this.send(packets)
})
}
if (packet.options && typeof packet.options.wsPreEncoded === "string") {
send(packet.options.wsPreEncoded)
} else {
this.parser.encodePacket(packet, this.supportsBinary, send)
}
}
/**
* Closes the transport.
*
* @api private
*/
doClose(fn) {
// debug("closing")
this.socket.close()
fn && fn()
}
}