remix-project/src/websocket.js

#!/usr/bin/env node
var WebSocketServer = require('websocket').server
var http = require('http')

class WebSocket {
  constructor (port, opt) {
    this.connection = null
    this.port = port
    this.opt = opt
  }

  start (callback) {
    this.server = http.createServer(function (request, response) {
      console.log((new Date()) + ' Received request for ' + request.url)
      response.writeHead(404)
      response.end()
    })
    var loopback = '127.0.0.1'
    this.server.listen(this.port, loopback, function () {
      console.log((new Date()) + ' Remixd is listening on ' + loopback + ':65520')
    })

    this.wsServer = new WebSocketServer({
      httpServer: this.server,
      autoAcceptConnections: false
    })

    this.wsServer.on('request', (request) => {
      if (!originIsAllowed(request.origin, this)) {
        request.reject()
        console.log((new Date()) + ' Connection from origin ' + request.origin + ' rejected.')
        return
      }
      if (this.connection) {
        console.log('closing previous connection')
        this.wsServer.closeAllConnections()
        this.connection = null
        return
      }

      this.connection = request.accept('echo-protocol', request.origin)
      console.log((new Date()) + ' Connection accepted.')
      this.connection.on('message', (message) => {
        if (message.type === 'utf8') {
          callback(JSON.parse(message.utf8Data))
        }
      })
      this.connection.on('close', (reasonCode, description) => {
        console.log((new Date()) + ' Remix ' + this.connection.remoteAddress + ' disconnected.')
        this.connection = null
      })
    })
  }

  send (data) {
    this.connection.sendUTF(data)
  }

  close () {
    if (this.connection) {
      this.connection.close()
      this.connection = null
    }
    if (this.server) {
      this.server.close()
      this.server = null
    }
  }
}

function originIsAllowed (origin, self) {
  return origin === self.opt.remixIdeUrl
}

module.exports = WebSocket