From 8ca18f0b602a08cd9a5c9f6681bb5dc74e0d34f7 Mon Sep 17 00:00:00 2001
From: Joshua Gross <joshuagross@fb.com>
Date: Wed, 2 Jun 2021 12:48:42 -0700
Subject: [PATCH] Don't PreAllocate virtual views

Summary:
Virtual views that are flattened and don't "FormsView" on-screen should not be preallocated.

Changelog: [Internal]

Reviewed By: mdvacca

Differential Revision: D28811419

fbshipit-source-id: 949dcbf4cf3791355c58af785603b35fa50f3f02
---
 .../src/main/java/com/facebook/react/fabric/jni/Binding.cpp | 6 +++++-
 ReactCommon/react/renderer/mounting/ShadowView.cpp          | 2 ++
 ReactCommon/react/renderer/mounting/ShadowView.h            | 1 +
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/ReactAndroid/src/main/java/com/facebook/react/fabric/jni/Binding.cpp b/ReactAndroid/src/main/java/com/facebook/react/fabric/jni/Binding.cpp
index 2945893c05d..73e43c2a18b 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/fabric/jni/Binding.cpp
+++ b/ReactAndroid/src/main/java/com/facebook/react/fabric/jni/Binding.cpp
@@ -561,6 +561,9 @@ void Binding::installFabricUIManager(
   disablePreallocateViews_ = reactNativeConfig_->getBool(
       "react_fabric:disabled_view_preallocation_android");
 
+  disableVirtualNodePreallocation_ = reactNativeConfig_->getBool(
+      "react_fabric:disable_virtual_node_preallocation");
+
   auto toolbox = SchedulerToolbox{};
   toolbox.contextContainer = contextContainer;
   toolbox.componentRegistryFactory = componentsRegistry->buildRegistryFunction;
@@ -1141,7 +1144,8 @@ void Binding::schedulerDidRequestPreliminaryViewAllocation(
 
   bool isLayoutableShadowNode = shadowView.layoutMetrics != EmptyLayoutMetrics;
 
-  if (disableVirtualNodePreallocation_ && !isLayoutableShadowNode) {
+  if (disableVirtualNodePreallocation_ &&
+      !shadowView.traits.check(ShadowNodeTraits::Trait::FormsView)) {
     return;
   }
 
diff --git a/ReactCommon/react/renderer/mounting/ShadowView.cpp b/ReactCommon/react/renderer/mounting/ShadowView.cpp
index 203a1fc95b3..3b4b54f1439 100644
--- a/ReactCommon/react/renderer/mounting/ShadowView.cpp
+++ b/ReactCommon/react/renderer/mounting/ShadowView.cpp
@@ -25,6 +25,7 @@ ShadowView::ShadowView(const ShadowNode &shadowNode)
       componentHandle(shadowNode.getComponentHandle()),
       surfaceId(shadowNode.getSurfaceId()),
       tag(shadowNode.getTag()),
+      traits(shadowNode.getTraits()),
       props(shadowNode.getProps()),
       eventEmitter(shadowNode.getEventEmitter()),
       layoutMetrics(layoutMetricsFromShadowNode(shadowNode)),
@@ -65,6 +66,7 @@ std::vector<DebugStringConvertibleObject> getDebugProps(
   return {
       {"surfaceId", getDebugDescription(object.surfaceId, options)},
       {"tag", getDebugDescription(object.tag, options)},
+      {"traits", getDebugDescription(object.traits, options)},
       {"componentName", object.componentName},
       {"props", getDebugDescription(object.props, options)},
       {"eventEmitter", getDebugDescription(object.eventEmitter, options)},
diff --git a/ReactCommon/react/renderer/mounting/ShadowView.h b/ReactCommon/react/renderer/mounting/ShadowView.h
index 3631551ae19..614399b2fb0 100644
--- a/ReactCommon/react/renderer/mounting/ShadowView.h
+++ b/ReactCommon/react/renderer/mounting/ShadowView.h
@@ -43,6 +43,7 @@ struct ShadowView final {
   ComponentHandle componentHandle{};
   SurfaceId surfaceId{};
   Tag tag{};
+  ShadowNodeTraits traits{};
   Props::Shared props{};
   EventEmitter::Shared eventEmitter{};
   LayoutMetrics layoutMetrics{EmptyLayoutMetrics};