From 05862faab478bad880d305f40e681c2011edfcc5 Mon Sep 17 00:00:00 2001
From: Valentin Shergin <shergin@fb.com>
Date: Wed, 16 Oct 2019 17:51:09 -0700
Subject: [PATCH] Farbic: Making `ShadowNode::revision_` debug only

Summary:
We use this piece of data only for debug purposes, so there is no need to pay for that in prod.

Changelog: [Internal] - Small optimization in `ShadowNode` (Fabric)

Reviewed By: JoshuaGross

Differential Revision: D17961209

fbshipit-source-id: 2a0d609ac4d3c4815b26789551a4c51bcf91dea4
---
 .../fabric/core/shadownode/ShadowNode.cpp      | 18 ++++++++++++------
 .../fabric/core/shadownode/ShadowNode.h        | 14 +++++++-------
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/ReactCommon/fabric/core/shadownode/ShadowNode.cpp b/ReactCommon/fabric/core/shadownode/ShadowNode.cpp
index 826c2c8a297..ff105215be2 100644
--- a/ReactCommon/fabric/core/shadownode/ShadowNode.cpp
+++ b/ReactCommon/fabric/core/shadownode/ShadowNode.cpp
@@ -34,7 +34,11 @@ bool ShadowNode::sameFamily(const ShadowNode &first, const ShadowNode &second) {
 ShadowNode::ShadowNode(
     const ShadowNodeFragment &fragment,
     const ComponentDescriptor &componentDescriptor)
-    : props_(fragment.props),
+    :
+#if RN_DEBUG_STRING_CONVERTIBLE
+      revision_(1),
+#endif
+      props_(fragment.props),
       children_(
           fragment.children ? fragment.children
                             : emptySharedShadowNodeSharedList()),
@@ -44,8 +48,7 @@ ShadowNode::ShadowNode(
           fragment.surfaceId,
           fragment.eventEmitter,
           componentDescriptor)),
-      childrenAreShared_(true),
-      revision_(1) {
+      childrenAreShared_(true) {
   assert(props_);
   assert(children_);
 
@@ -57,7 +60,11 @@ ShadowNode::ShadowNode(
 ShadowNode::ShadowNode(
     const ShadowNode &sourceShadowNode,
     const ShadowNodeFragment &fragment)
-    : props_(fragment.props ? fragment.props : sourceShadowNode.props_),
+    :
+#if RN_DEBUG_STRING_CONVERTIBLE
+      revision_(sourceShadowNode.revision_ + 1),
+#endif
+      props_(fragment.props ? fragment.props : sourceShadowNode.props_),
       children_(
           fragment.children ? fragment.children : sourceShadowNode.children_),
       localData_(
@@ -67,8 +74,7 @@ ShadowNode::ShadowNode(
           fragment.state ? fragment.state
                          : sourceShadowNode.getMostRecentState()),
       family_(sourceShadowNode.family_),
-      childrenAreShared_(true),
-      revision_(sourceShadowNode.revision_ + 1) {
+      childrenAreShared_(true) {
   // `tag`, `surfaceId`, and `eventEmitter` cannot be changed with cloning.
   assert(fragment.tag == ShadowNodeFragment::tagPlaceholder());
   assert(fragment.surfaceId == ShadowNodeFragment::surfaceIdPlaceholder());
diff --git a/ReactCommon/fabric/core/shadownode/ShadowNode.h b/ReactCommon/fabric/core/shadownode/ShadowNode.h
index b2e439dbf0b..61fc8056bf4 100644
--- a/ReactCommon/fabric/core/shadownode/ShadowNode.h
+++ b/ReactCommon/fabric/core/shadownode/ShadowNode.h
@@ -169,6 +169,13 @@ class ShadowNode : public virtual Sealable,
   std::string getDebugValue() const override;
   SharedDebugStringConvertibleList getDebugChildren() const override;
   SharedDebugStringConvertibleList getDebugProps() const override;
+
+  /*
+   * A number of the generation of the ShadowNode instance;
+   * is used and useful for debug-printing purposes *only*.
+   * Do not access this value in any circumstances.
+   */
+  int const revision_;
 #endif
 
  protected:
@@ -194,13 +201,6 @@ class ShadowNode : public virtual Sealable,
    * to be cloned before the first mutation.
    */
   bool childrenAreShared_;
-
-  /*
-   * A number of the generation of the ShadowNode instance;
-   * is used and useful for debug-printing purposes *only*.
-   * Do not access this value in any circumstances.
-   */
-  const int revision_;
 };
 
 } // namespace react