Skip unchanged children when slicing in the differ

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlags.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<cfa7aa53731059247d858fd8fb6e914b>>
+ * @generated SignedSource<<48b4420f0396dcad107bf821fcec61b3>>
  */
 
 /**
@@ -498,6 +498,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun skipActivityIdentityAssertionOnHostPause(): Boolean = accessor.skipActivityIdentityAssertionOnHostPause()
 
+  /**
+   * When a node changes, the differ leaves out its children that are unchanged in both trees instead of describing and comparing them.
+   */
+  @JvmStatic
+  public fun skipUnchangedChildrenInDifferentiator(): Boolean = accessor.skipUnchangedChildrenInDifferentiator()
+
   /**
    * Override getClipBounds on Android views to return the padding box when overflow is hidden
    */

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<71d0554dc45df7d5365f81b7ec8c3d5b>>
+ * @generated SignedSource<<aee24a31995e8cf214c5b765d58eddab>>
  */
 
 /**
@@ -98,6 +98,7 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var shouldPressibilityUseW3CPointerEventsForHoverCache: Boolean? = null
   private var shouldTriggerResponderTransferOnScrollAndroidCache: Boolean? = null
   private var skipActivityIdentityAssertionOnHostPauseCache: Boolean? = null
+  private var skipUnchangedChildrenInDifferentiatorCache: Boolean? = null
   private var syncAndroidClipBoundsWithOverflowCache: Boolean? = null
   private var traceTurboModulePromiseRejectionsOnAndroidCache: Boolean? = null
   private var updateRuntimeShadowNodeReferencesOnCommitCache: Boolean? = null
@@ -817,6 +818,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun skipUnchangedChildrenInDifferentiator(): Boolean {
+    var cached = skipUnchangedChildrenInDifferentiatorCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.skipUnchangedChildrenInDifferentiator()
+      skipUnchangedChildrenInDifferentiatorCache = cached
+    }
+    return cached
+  }
+
   override fun syncAndroidClipBoundsWithOverflow(): Boolean {
     var cached = syncAndroidClipBoundsWithOverflowCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxInterop.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<312cec99bd429d22e25f4e82d7fc4ee7>>
+ * @generated SignedSource<<f3e7d2e5c64e9e85e6e5d90e949198c7>>
  */
 
 /**
@@ -184,6 +184,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun skipActivityIdentityAssertionOnHostPause(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun skipUnchangedChildrenInDifferentiator(): Boolean
+
   @DoNotStrip @JvmStatic public external fun syncAndroidClipBoundsWithOverflow(): Boolean
 
   @DoNotStrip @JvmStatic public external fun traceTurboModulePromiseRejectionsOnAndroid(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsDefaults.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<669f16e131d4a5ddc026ffecc6893575>>
+ * @generated SignedSource<<3b2153df84f2c0193f32a5c5bf312700>>
  */
 
 /**
@@ -179,6 +179,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun skipActivityIdentityAssertionOnHostPause(): Boolean = false
 
+  override fun skipUnchangedChildrenInDifferentiator(): Boolean = false
+
   override fun syncAndroidClipBoundsWithOverflow(): Boolean = false
 
   override fun traceTurboModulePromiseRejectionsOnAndroid(): Boolean = false

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsLocalAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<ee4c0f9c1e7c6af3b0d15948ebc519b3>>
+ * @generated SignedSource<<2a0c2c71f3da4657d0f7b26548542c0d>>
  */
 
 /**
@@ -102,6 +102,7 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var shouldPressibilityUseW3CPointerEventsForHoverCache: Boolean? = null
   private var shouldTriggerResponderTransferOnScrollAndroidCache: Boolean? = null
   private var skipActivityIdentityAssertionOnHostPauseCache: Boolean? = null
+  private var skipUnchangedChildrenInDifferentiatorCache: Boolean? = null
   private var syncAndroidClipBoundsWithOverflowCache: Boolean? = null
   private var traceTurboModulePromiseRejectionsOnAndroidCache: Boolean? = null
   private var updateRuntimeShadowNodeReferencesOnCommitCache: Boolean? = null
@@ -899,6 +900,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun skipUnchangedChildrenInDifferentiator(): Boolean {
+    var cached = skipUnchangedChildrenInDifferentiatorCache
+    if (cached == null) {
+      cached = currentProvider.skipUnchangedChildrenInDifferentiator()
+      accessedFeatureFlags.add("skipUnchangedChildrenInDifferentiator")
+      skipUnchangedChildrenInDifferentiatorCache = cached
+    }
+    return cached
+  }
+
   override fun syncAndroidClipBoundsWithOverflow(): Boolean {
     var cached = syncAndroidClipBoundsWithOverflowCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<18267103ef4f3eb22f23a15b808528c2>>
+ * @generated SignedSource<<ce6c47765ea7c722641a72668578918d>>
  */
 
 /**
@@ -179,6 +179,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun skipActivityIdentityAssertionOnHostPause(): Boolean
 
+  @DoNotStrip public fun skipUnchangedChildrenInDifferentiator(): Boolean
+
   @DoNotStrip public fun syncAndroidClipBoundsWithOverflow(): Boolean
 
   @DoNotStrip public fun traceTurboModulePromiseRejectionsOnAndroid(): Boolean

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<568d6e4175fb51e09bc3d4441ffa9741>>
+ * @generated SignedSource<<d4874865e8c407d1fd6fa1359fa65ef1>>
  */
 
 /**
@@ -507,6 +507,12 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
+  bool skipUnchangedChildrenInDifferentiator() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("skipUnchangedChildrenInDifferentiator");
+    return method(javaProvider_);
+  }
+
   bool syncAndroidClipBoundsWithOverflow() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("syncAndroidClipBoundsWithOverflow");
@@ -997,6 +1003,11 @@ bool JReactNativeFeatureFlagsCxxInterop::skipActivityIdentityAssertionOnHostPaus
   return ReactNativeFeatureFlags::skipActivityIdentityAssertionOnHostPause();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::skipUnchangedChildrenInDifferentiator(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::skipUnchangedChildrenInDifferentiator();
+}
+
 bool JReactNativeFeatureFlagsCxxInterop::syncAndroidClipBoundsWithOverflow(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::syncAndroidClipBoundsWithOverflow();
@@ -1342,6 +1353,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "skipActivityIdentityAssertionOnHostPause",
         JReactNativeFeatureFlagsCxxInterop::skipActivityIdentityAssertionOnHostPause),
+      makeNativeMethod(
+        "skipUnchangedChildrenInDifferentiator",
+        JReactNativeFeatureFlagsCxxInterop::skipUnchangedChildrenInDifferentiator),
       makeNativeMethod(
         "syncAndroidClipBoundsWithOverflow",
         JReactNativeFeatureFlagsCxxInterop::syncAndroidClipBoundsWithOverflow),

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<2e0f936c003aafc456ab3f960ca4b2f3>>
+ * @generated SignedSource<<79e3a5e32cd586b32e2c20c4f586c207>>
  */
 
 /**
@@ -264,6 +264,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool skipActivityIdentityAssertionOnHostPause(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool skipUnchangedChildrenInDifferentiator(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static bool syncAndroidClipBoundsWithOverflow(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<f90778065a9a5f48383dd9b4606bd862>>
+ * @generated SignedSource<<deb7cbcd0e6d7e5f8fd4898a27773d27>>
  */
 
 /**
@@ -338,6 +338,10 @@ bool ReactNativeFeatureFlags::skipActivityIdentityAssertionOnHostPause() {
   return getAccessor().skipActivityIdentityAssertionOnHostPause();
 }
 
+bool ReactNativeFeatureFlags::skipUnchangedChildrenInDifferentiator() {
+  return getAccessor().skipUnchangedChildrenInDifferentiator();
+}
+
 bool ReactNativeFeatureFlags::syncAndroidClipBoundsWithOverflow() {
   return getAccessor().syncAndroidClipBoundsWithOverflow();
 }

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<62dbb584d6aaf595314636a81346e3e5>>
+ * @generated SignedSource<<349d1fffdceddf1b43927718ee193317>>
  */
 
 /**
@@ -431,6 +431,11 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool skipActivityIdentityAssertionOnHostPause();
 
+  /**
+   * When a node changes, the differ leaves out its children that are unchanged in both trees instead of describing and comparing them.
+   */
+  RN_EXPORT static bool skipUnchangedChildrenInDifferentiator();
+
   /**
    * Override getClipBounds on Android views to return the padding box when overflow is hidden
    */