Only execute update block once

Summary:
We were executing all the updateBlocks for every frame that was updated in the UI flush. This would quickly give you an explosive number of block calls when loading complex views.

This update block is only really used by text to propagate padding, even though the actual insets are mostly just 0.

public

Reviewed By: nicklockwood

Differential Revision: D2848968

fb-gh-sync-id: e43c529c2bb9729e2b779bf4abefeed58775cc2e

React/Modules/RCTUIManager.m

@@ -483,6 +483,8 @@ - (RCTViewManagerUIBlock)uiBlockWithLayoutUpdateForRootView:(RCTShadowView *)roo
     [NSMutableArray arrayWithCapacity:viewsWithNewFrames.count];
   NSMutableArray<NSNumber *> *parentsAreNew =
     [NSMutableArray arrayWithCapacity:viewsWithNewFrames.count];
+  NSMutableDictionary<NSNumber *, RCTViewManagerUIBlock> *updateBlocks =
+    [NSMutableDictionary new];
 
   for (RCTShadowView *shadowView in viewsWithNewFrames) {
     [frameReactTags addObject:shadowView.reactTag];
@@ -500,10 +502,13 @@ - (RCTViewManagerUIBlock)uiBlockWithLayoutUpdateForRootView:(RCTShadowView *)roo
   // reactSetFrame: has been called. Note that if reactSetFrame: is not called,
   // these won't be called either, so this is not a suitable place to update
   // properties that aren't related to layout.
-  NSMutableArray<RCTViewManagerUIBlock> *updateBlocks = [NSMutableArray new];
   for (RCTShadowView *shadowView in viewsWithNewFrames) {
     RCTViewManager *manager = [_componentDataByName[shadowView.viewName] manager];
     RCTViewManagerUIBlock block = [manager uiBlockToAmendWithShadowView:shadowView];
+    if (block) {
+      updateBlocks[shadowView.reactTag] = block;
+    }
+
     if (shadowView.onLayout) {
       CGRect frame = shadowView.frame;
       shadowView.onLayout(@{
@@ -525,14 +530,9 @@ - (RCTViewManagerUIBlock)uiBlockWithLayoutUpdateForRootView:(RCTShadowView *)roo
         RCTAssert(view != nil, @"view (for ID %@) not found", reactTag);
 
         RCTRootView *rootView = (RCTRootView *)[view superview];
-
         rootView.intrinsicSize = contentSize;
       });
     }
-
-    if (block) {
-      [updateBlocks addObject:block];
-    }
   }
 
   // Perform layout (possibly animated)
@@ -561,31 +561,18 @@ - (RCTViewManagerUIBlock)uiBlockWithLayoutUpdateForRootView:(RCTShadowView *)roo
         }
       };
 
-      // Animate view update
-      if (updateAnimation) {
-        [updateAnimation performAnimations:^{
-          [view reactSetFrame:frame];
-          for (RCTViewManagerUIBlock block in updateBlocks) {
-            block(self, _viewRegistry);
-          }
-        } withCompletionBlock:completion];
-      } else {
-        [view reactSetFrame:frame];
-        for (RCTViewManagerUIBlock block in updateBlocks) {
-          block(self, _viewRegistry);
-        }
-        completion(YES);
-      }
-
       // Animate view creation
       if (createAnimation) {
+        [view reactSetFrame:frame];
+
         CATransform3D finalTransform = view.layer.transform;
         CGFloat finalOpacity = view.layer.opacity;
         if ([createAnimation.property isEqualToString:@"scaleXY"]) {
           view.layer.transform = CATransform3DMakeScale(0, 0, 0);
         } else if ([createAnimation.property isEqualToString:@"opacity"]) {
           view.layer.opacity = 0.0;
         }
+
         [createAnimation performAnimations:^{
           if ([createAnimation.property isEqual:@"scaleXY"]) {
             view.layer.transform = finalTransform;
@@ -595,10 +582,33 @@ - (RCTViewManagerUIBlock)uiBlockWithLayoutUpdateForRootView:(RCTShadowView *)roo
             RCTLogError(@"Unsupported layout animation createConfig property %@",
                         createAnimation.property);
           }
-          for (RCTViewManagerUIBlock block in updateBlocks) {
-            block(self, _viewRegistry);
+
+          RCTViewManagerUIBlock updateBlock = updateBlocks[reactTag];
+          if (updateBlock) {
+            updateBlock(self, _viewRegistry);
+          }
+        } withCompletionBlock:completion];
+
+      // Animate view update
+      } else if (updateAnimation) {
+        [updateAnimation performAnimations:^{
+          [view reactSetFrame:frame];
+
+          RCTViewManagerUIBlock updateBlock = updateBlocks[reactTag];
+          if (updateBlock) {
+            updateBlock(self, _viewRegistry);
           }
-        } withCompletionBlock:nil];
+        } withCompletionBlock:completion];
+
+      // Update without animation
+      } else {
+        [view reactSetFrame:frame];
+
+        RCTViewManagerUIBlock updateBlock = updateBlocks[reactTag];
+        if (updateBlock) {
+          updateBlock(self, _viewRegistry);
+        }
+        completion(YES);
       }
     }
   };