Merge pull request #1093 from nguyenhuy/improve_reload_data

[ASDataController] Optimize reloadData to avoid performing deletions or insertions.

AsyncDisplayKit/ASCollectionView.mm

@@ -250,7 +250,7 @@ static NSString * const kCellReuseIdentifier = @"_ASCollectionViewCell";
     _superIsPendingDataLoad = YES;
     [super reloadData];
   });
-  [_dataController reloadDataWithAnimationOptions:kASCollectionViewAnimationNone completion:completion];
+  [_dataController reloadDataWithCompletion:completion];
 }
 
 - (void)reloadData
@@ -262,7 +262,7 @@ static NSString * const kCellReuseIdentifier = @"_ASCollectionViewCell";
 {
   ASDisplayNodeAssertMainThread();
   _superIsPendingDataLoad = YES;
-  [_dataController reloadDataImmediatelyWithAnimationOptions:kASCollectionViewAnimationNone];
+  [_dataController reloadDataImmediately];
   [super reloadData];
 }
 
@@ -938,6 +938,25 @@ static NSString * const kCellReuseIdentifier = @"_ASCollectionViewCell";
   }
 }
 
+- (void)rangeControllerDidReloadData:(ASRangeController *)rangeController
+{
+  ASDisplayNodeAssertMainThread();
+  
+  if (!self.asyncDataSource || _superIsPendingDataLoad) {
+    return; // if the asyncDataSource has become invalid while we are processing, ignore this request to avoid crashes
+  }
+  
+  if (_performingBatchUpdates) {
+    [_batchUpdateBlocks addObject:^{
+      [super reloadData];
+    }];
+  } else {
+    [UIView performWithoutAnimation:^{
+      [super reloadData];
+    }];
+  }
+}
+
 #pragma mark - ASCellNodeDelegate
 
 - (void)nodeDidRelayout:(ASCellNode *)node sizeChanged:(BOOL)sizeChanged