web3-provider-engine/util/stoplight.js

A JavaScript library for composing Ethereum provider objects using middleware modules

const EventEmitter = require('events').EventEmitter
const inherits = require('util').inherits

module.exports = Stoplight


inherits(Stoplight, EventEmitter)

function Stoplight(){
  const self = this
  EventEmitter.call(self)
  self.isLocked = true
}

Stoplight.prototype.go = function(){
  const self = this
  self.isLocked = false
  self.emit('unlock')
}

Stoplight.prototype.stop = function(){
  const self = this
  self.isLocked = true
  self.emit('lock')
}

Stoplight.prototype.await = function(fn){
  const self = this
  if (self.isLocked) {
    self.once('unlock', fn)
  } else {
    setTimeout(fn)
  }
}