1 files changed, 55 insertions, 0 deletions
diff --git a/node_modules/nanoscheduler/index.js b/node_modules/nanoscheduler/index.js
new file mode 100644
index 00000000..c9dc7535
--- /dev/null
+++ b/node_modules/nanoscheduler/index.js
@@ -0,0 +1,55 @@
+var assert = require('assert')
+
+var hasWindow = typeof window !== 'undefined'
+
+function createScheduler () {
+  var scheduler
+  if (hasWindow) {
+    if (!window._nanoScheduler) window._nanoScheduler = new NanoScheduler(true)
+    scheduler = window._nanoScheduler
+  } else {
+    scheduler = new NanoScheduler()
+  }
+  return scheduler
+}
+
+function NanoScheduler (hasWindow) {
+  this.hasWindow = hasWindow
+  this.hasIdle = this.hasWindow && window.requestIdleCallback
+  this.method = this.hasIdle ? window.requestIdleCallback.bind(window) : this.setTimeout
+  this.scheduled = false
+  this.queue = []
+}
+
+NanoScheduler.prototype.push = function (cb) {
+  assert.equal(typeof cb, 'function', 'nanoscheduler.push: cb should be type function')
+
+  this.queue.push(cb)
+  this.schedule()
+}
+
+NanoScheduler.prototype.schedule = function () {
+  if (this.scheduled) return
+
+  this.scheduled = true
+  var self = this
+  this.method(function (idleDeadline) {
+    var cb
+    while (self.queue.length && idleDeadline.timeRemaining() > 0) {
+      cb = self.queue.shift()
+      cb(idleDeadline)
+    }
+    self.scheduled = false
+    if (self.queue.length) self.schedule()
+  })
+}
+
+NanoScheduler.prototype.setTimeout = function (cb) {
+  setTimeout(cb, 0, {
+    timeRemaining: function () {
+      return 1
+    }
+  })
+}
+
+module.exports = createScheduler