Parser.prototype._parseConnect = function()

in digital-shadow/demo-car/js/aws-iot/aws-iot.js [10530:10615]

• 67 lines of code
• 18 McCabe index (conditional complexity)

Parser.prototype._parseConnect = function () {
  var protocolId // constants id
    , clientId // Client id
    , topic // Will topic
    , payload // Will payload
    , password // Password
    , username // Username
    , flags = {}
    , packet = this.packet

  protocolId = this._parseString()
  if (protocolId === null)
    return this._emitError(new Error('cannot parse protocol id'))

  if (protocolId != 'MQTT' && protocolId != 'MQIsdp') {

    return this._emitError(new Error('invalid protocol id'))
  }

  packet.protocolId = protocolId

  if(this._pos >= this._list.length)
    return this._emitError(new Error('packet too short'))

  packet.protocolVersion = this._list.readUInt8(this._pos)

  if(packet.protocolVersion != 3 && packet.protocolVersion != 4) {

    return this._emitError(new Error('invalid protocol version'))
  }

  this._pos++
  if(this._pos >= this._list.length)
    return this._emitError(new Error('packet too short'))

  flags.username  = (this._list.readUInt8(this._pos) & constants.USERNAME_MASK)
  flags.password  = (this._list.readUInt8(this._pos) & constants.PASSWORD_MASK)
  flags.will      = (this._list.readUInt8(this._pos) & constants.WILL_FLAG_MASK)

  if (flags.will) {
    packet.will         = {}
    packet.will.retain  = (this._list.readUInt8(this._pos) & constants.WILL_RETAIN_MASK) !== 0
    packet.will.qos     = (this._list.readUInt8(this._pos) &
                          constants.WILL_QOS_MASK) >> constants.WILL_QOS_SHIFT
  }

  packet.clean = (this._list.readUInt8(this._pos) & constants.CLEAN_SESSION_MASK) !== 0
  this._pos++

  packet.keepalive = this._parseNum()
  if(packet.keepalive === -1)
    return this._emitError(new Error('packet too short'))

  clientId = this._parseString()
  if(clientId === null)
    return this._emitError(new Error('packet too short'))
  packet.clientId = clientId

  if (flags.will) {
    topic = this._parseString()
    if (topic === null)
      return this._emitError(new Error('cannot parse will topic'))
    packet.will.topic = topic

    payload = this._parseBuffer()
    if (payload === null)
      return this._emitError(new Error('cannot parse will payload'))
    packet.will.payload = payload
  }

  if (flags.username) {
    username = this._parseString()
    if(username === null)
      return this._emitError(new Error('cannot parse username'))
    packet.username = username
  }

  if(flags.password) {
    password = this._parseBuffer()
    if(password === null)
      return this._emitError(new Error('cannot parse username'))
    packet.password = password
  }

  return packet
}