poll_watcher.js

var helpers = require('broccoli-kitchen-sink-helpers')
var RSVP = require('rsvp')


module.exports = PollWatcher
RSVP.EventTarget.mixin(PollWatcher.prototype)
function PollWatcher(options) {
  this.options = options || {}
  if (this.options.interval == null) this.options.interval = 100
  this.treeHash = null
}

PollWatcher.prototype.watch = function(watchedPaths) {
  this.watchedPaths = watchedPaths
  this.intervalID = setInterval(this._check.bind(this), this.options.interval)
}

PollWatcher.prototype.quit = function() {
  clearTimeout(this.intervalID)
}

PollWatcher.prototype._computeTreeHash = function() {
  return helpers.hashStrings(this.watchedPaths.map(function(watchedPath) {
    return helpers.hashTree(watchedPath)
  }))
}

PollWatcher.prototype._check = function() {
  try {
    var newTreeHash = this._computeTreeHash()
    // Check if anything changed or if we're running for the first time
    if (newTreeHash !== this.treeHash) {
      this.treeHash = newTreeHash
      this.trigger('change')
    }
  } catch (err) {
    // This can happen if one of the watchedPaths is missing
    this.trigger('error', err)
  }
}