Scheduler

gistfile1.txt

function importScript (path) {
  var tag = 'script'
  var scriptTag = document.createElement(tag),
      firstScriptTag = document.getElementsByTagName(tag)[0];
  scriptTag.src = path
  firstScriptTag.parentNode.insertBefore(scriptTag, firstScriptTag);
}

importScript('https://rawgit.com/AStaroverov/Scheduler/master/Scheduler.js')

if (!window.setImmediate) {
    importScript('https://cdnjs.cloudflare.com/ajax/libs/setImmediate/1.0.5/setImmediate.min.js')
}

var resolved = Promise.resolve();
function nextTick (fn) {
  resolved.then(fn)
}

function getTaskWrapperFunction (task) {
  const { priority } = task

  switch (true) {
    case priority < 200: {
      return // sync perform
    }
    case priority < 600: {
      return nextTick
    }
    case priority < 800: {
      return setImmediate
    }
    default: {
      return setTimeout
    }
  }
}

var raf = window.requestAnimationFrame
function doubleRaf (cb) { return raf(() => raf(cb)) }
function longRaf (cb) { return setTimeout(cb, 16 * 4) }
function getFrameFunction (tasksForFrame) {
  var countTasks = tasksForFrame.length

  switch (true) {
    case countTasks < 30: {
      return raf
    }
    case countTasks < 100: {
      return doubleRaf
    }
    default: {
      return longRaf
    }
  }
}

// 3 sec for start chrome profiler :)
setTimeout(() => {
var sch = new Scheduler.default({ getTaskWrapperFunction, getFrameFunction })

var i = 1000
while (i--) {
    (function (id) {
        var priority = id

        sch.addTask({
            handler () {
                var div = document.createElement('div')
                div.innerHTML = `some text task ${priority}`
                document.body.appendChild(div)
                console.log()
            },
            priority
        })
    })(i)
}

var i = 200
while (i--) {
    (function (id) {
        var priority = parseInt(id * Math.random() * 10)

        sch.subscribeTask({
            handler () {
                var div = document.createElement('div')
                div.innerHTML = `some text subscribeTask ${priority}`
                document.body.appendChild(div)
            },
            priority
        })
    })(i)    
}

sch.start()
setTimeout(() => {
    sch.stop()
    console.log(sch)
}, 5000)

}, 3000)

can run inside latest chrome