先是 

  return createServer()
      .then(function(wss) {
        var frameProducer = new FrameProducer(
          new FrameConfig(display.properties, display.properties))
        var broadcastSet = frameProducer.broadcastSet = new BroadcastSet()

然后

  ws.on('message', function(data) {
            var match = /^(on|off|(size) ([0-9]+)x([0-9]+))$/.exec(data)
            if (match) {
              switch (match[2] || match[1]) {
              case 'on':
                broadcastSet.insert(id, {
                  onStart: wsStartNotifier
                , onFrame: wsFrameNotifier
                })
                break

再然后

BroadcastSet.prototype.insert = function(id, ws) {
  if (!(id in this.set)) {
    this.set[id] = ws
    this.count += 1
    this.emit('insert', id)
    if (this.count === 1) {
      this.emit('nonempty')
    }
  }
}

再次

   broadcastSet.on('nonempty', function() {
          frameProducer.start()
        })

然后

 FrameProducer.prototype.start = function() {
      log.info('Requesting frame producer to start')
      this.desiredState.push(FrameProducer.STATE_STARTED)
      this._ensureState()
    }

然后

       .then(function(banner) {
              this.banner = banner
              return this._readFrames(this.socket.stream)
            })
            .then(function() {
              this.runningState = FrameProducer.STATE_STARTED
              this.emit('start')
            })

然后

    FrameProducer.prototype._readFrames = function(socket) {
      this.needsReadable = true
      socket.on('readable', this.readableListener)

      // We may already have data pending. Let the user know they should
      // at least attempt to read frames now.
      this.readableListener()
    }

与

        frameProducer.on('start', function() {
          broadcastSet.keys().map(function(id) {
            return broadcastSet.get(id).onStart(frameProducer)
          })
        })

然后

   this.readableListener = this._readableListener.bind(this)

然后

   FrameProducer.prototype._readableListener = function() {
      this.readable = true
      this._maybeEmitReadable()
    }

然后

   FrameProducer.prototype._maybeEmitReadable = function() {
      if (this.readable && this.needsReadable) {
        this.needsReadable = false
        this.emit('readable')
      }
    }

然后

    frameProducer.on('readable', function next() {
          var frame = frameProducer.nextFrame()
          if (frame) {
            Promise.settle([broadcastSet.keys().map(function(id) {
              return broadcastSet.get(id).onFrame(frame)
            })]).then(next)
          }
          else {
            frameProducer.needFrame()
          }
        })

然后

    FrameProducer.prototype.nextFrame = function() {
      var frame = null
      var chunk

      if (this.parser) {
        while ((frame = this.parser.nextFrame()) === null) {
          chunk = this.socket.stream.read()
          if (chunk) {
            this.parser.push(chunk)
          }
          else {
            this.readable = false
            break
          }
        }
      }

      return frame
    }

再然后

   function wsFrameNotifier(frame) {
            return send(frame, {
              binary: true
            })
          }