From fb9d15e03e4e763ffd3bcd35c264dbdacc30aede Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Wed, 22 Jul 2015 16:03:39 -0600
Subject: [PATCH] Throttle document polling

---
 src/view-registry.coffee | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/view-registry.coffee b/src/view-registry.coffee
index 20c88394e..58b2bf7c0 100644
--- a/src/view-registry.coffee
+++ b/src/view-registry.coffee
@@ -1,6 +1,7 @@
 {find} = require 'underscore-plus'
 Grim = require 'grim'
 {Disposable} = require 'event-kit'
+_ = require 'underscore-plus'
 
 # Essential: `ViewRegistry` handles the association between model and view
 # types in Atom. We call this association a View Provider. As in, for a given
@@ -45,6 +46,8 @@ class ViewRegistry
   documentUpdateRequested: false
   documentReadInProgress: false
   performDocumentPollAfterUpdate: false
+  debouncedPerformDocumentPoll: null
+  minimumPollInterval: 200
 
   constructor: ->
     @views = new WeakMap
@@ -53,7 +56,8 @@ class ViewRegistry
     @documentReaders = []
     @documentPollers = []
 
-    @observer = new MutationObserver(@performDocumentPoll)
+    @observer = new MutationObserver(@requestDocumentPoll)
+    @debouncedPerformDocumentPoll = _.throttle(@performDocumentPoll, @minimumPollInterval).bind(this)
 
   # Essential: Add a provider that will be used to construct views in the
   # workspace's view layer based on model objects in its model layer.
@@ -208,16 +212,19 @@ class ViewRegistry
     writer() while writer = @documentWriters.shift()
 
   startPollingDocument: ->
-    window.addEventListener('resize', @performDocumentPoll)
+    window.addEventListener('resize', @requestDocumentPoll)
     @observer.observe(document, {subtree: true, childList: true, attributes: true})
 
   stopPollingDocument: ->
-    window.removeEventListener('resize', @performDocumentPoll)
+    window.removeEventListener('resize', @requestDocumentPoll)
     @observer.disconnect()
 
-  performDocumentPoll: =>
+  requestDocumentPoll: =>
     if @documentUpdateRequested
       @performDocumentPollAfterUpdate = true
     else
-      poller() for poller in @documentPollers
-      return
+      @debouncedPerformDocumentPoll()
+
+  performDocumentPoll: ->
+    poller() for poller in @documentPollers
+    return