From d65fe8b5fad29d79a324a0c49f1792df63b1d5f6 Mon Sep 17 00:00:00 2001
From: Adlai Holler <guy.on.internet@me.com>
Date: Wed, 4 Jan 2017 13:30:23 -0800
Subject: [PATCH] Disable UICollectionView prefetching to improve scroll
 performance (#2861)

---
 AsyncDisplayKit/ASCollectionView.mm | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/AsyncDisplayKit/ASCollectionView.mm b/AsyncDisplayKit/ASCollectionView.mm
index 5473d591a9..9cafd08518 100644
--- a/AsyncDisplayKit/ASCollectionView.mm
+++ b/AsyncDisplayKit/ASCollectionView.mm
@@ -280,7 +280,15 @@ static NSString * const kCellReuseIdentifier = @"_ASCollectionViewCell";
 {
   if (!(self = [super initWithFrame:frame collectionViewLayout:layout]))
     return nil;
-  
+
+  // Disable UICollectionView prefetching.
+  // Experiments done by Instagram show that this option being YES (default)
+  // when unused causes a significant hit to scroll performance.
+  // https://github.com/Instagram/IGListKit/issues/318
+  if (AS_AT_LEAST_IOS10) {
+    self.prefetchingEnabled = NO;
+  }
+
   _layoutController = [[ASCollectionViewLayoutController alloc] initWithCollectionView:self];
   
   _rangeController = [[ASRangeController alloc] init];