Pre-allocate mutation vectors in Differentiator to reduce reallocation overhead (#55819)

Summary:
Pull Request resolved: #55819

Changelog: [Internal]

speed up differentiator

| Test                          | Before (ms) | After (ms) | Improvement |
|-------------------------------|-------------|------------|-------------|
| 100 uncollapsable views       | 3.0         | 2.7        | +10%        |
| 1000 uncollapsable views      | 91.1        | 50.5       | +45%        |
| 100 views w/ many props       | 9.8         | 9.2        | +6%         |
| 1000 views w/ many props      | 147.4       | 116.7      | +21%        |
| 1500 views w/ many props      | 143.1       | 136.7      | +5%         |

Reviewed By: mdvacca

Differential Revision: D94096006

Author: sammy-SC

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<<156d4f5f35037184b6fc61ff1d856028>>
+ * @generated SignedSource<<2ca6b65f1103a486e4e5a006de629e76>>
  */
 
 /**
@@ -144,6 +144,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun enableDestroyShadowTreeRevisionAsync(): Boolean = accessor.enableDestroyShadowTreeRevisionAsync()
 
+  /**
+   * Pre-allocate mutation vectors in the Differentiator to reduce reallocation overhead during shadow view diffing.
+   */
+  @JvmStatic
+  public fun enableDifferentiatorMutationVectorPreallocation(): Boolean = accessor.enableDifferentiatorMutationVectorPreallocation()
+
   /**
    * When enabled a subset of components will avoid double measurement on Android.
    */

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<<0875d5e54d884a26d37bb4eb2acc57d5>>
+ * @generated SignedSource<<202662ab1c26ed104cfe837162d4f9a2>>
  */
 
 /**
@@ -39,6 +39,7 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var enableCppPropsIteratorSetterCache: Boolean? = null
   private var enableCustomFocusSearchOnClippedElementsAndroidCache: Boolean? = null
   private var enableDestroyShadowTreeRevisionAsyncCache: Boolean? = null
+  private var enableDifferentiatorMutationVectorPreallocationCache: Boolean? = null
   private var enableDoubleMeasurementFixAndroidCache: Boolean? = null
   private var enableEagerMainQueueModulesOnIOSCache: Boolean? = null
   private var enableEagerRootViewAttachmentCache: Boolean? = null
@@ -277,6 +278,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun enableDifferentiatorMutationVectorPreallocation(): Boolean {
+    var cached = enableDifferentiatorMutationVectorPreallocationCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.enableDifferentiatorMutationVectorPreallocation()
+      enableDifferentiatorMutationVectorPreallocationCache = cached
+    }
+    return cached
+  }
+
   override fun enableDoubleMeasurementFixAndroid(): Boolean {
     var cached = enableDoubleMeasurementFixAndroidCache
     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<<948a9beebe2ff00791a03455eb774eee>>
+ * @generated SignedSource<<03f5b76fefda14757a43414f6624601a>>
  */
 
 /**
@@ -66,6 +66,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun enableDestroyShadowTreeRevisionAsync(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun enableDifferentiatorMutationVectorPreallocation(): Boolean
+
   @DoNotStrip @JvmStatic public external fun enableDoubleMeasurementFixAndroid(): Boolean
 
   @DoNotStrip @JvmStatic public external fun enableEagerMainQueueModulesOnIOS(): 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<<89c61520177334f93c65ff92c2fc74a6>>
+ * @generated SignedSource<<7713ee7b0947f0ae8c66b73413a7f226>>
  */
 
 /**
@@ -61,6 +61,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun enableDestroyShadowTreeRevisionAsync(): Boolean = false
 
+  override fun enableDifferentiatorMutationVectorPreallocation(): Boolean = false
+
   override fun enableDoubleMeasurementFixAndroid(): Boolean = false
 
   override fun enableEagerMainQueueModulesOnIOS(): 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<<669708c311abe9ffc8f7783219e2baad>>
+ * @generated SignedSource<<79cf67c605a76059f010cf2ccd0ec64b>>
  */
 
 /**
@@ -43,6 +43,7 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var enableCppPropsIteratorSetterCache: Boolean? = null
   private var enableCustomFocusSearchOnClippedElementsAndroidCache: Boolean? = null
   private var enableDestroyShadowTreeRevisionAsyncCache: Boolean? = null
+  private var enableDifferentiatorMutationVectorPreallocationCache: Boolean? = null
   private var enableDoubleMeasurementFixAndroidCache: Boolean? = null
   private var enableEagerMainQueueModulesOnIOSCache: Boolean? = null
   private var enableEagerRootViewAttachmentCache: Boolean? = null
@@ -300,6 +301,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun enableDifferentiatorMutationVectorPreallocation(): Boolean {
+    var cached = enableDifferentiatorMutationVectorPreallocationCache
+    if (cached == null) {
+      cached = currentProvider.enableDifferentiatorMutationVectorPreallocation()
+      accessedFeatureFlags.add("enableDifferentiatorMutationVectorPreallocation")
+      enableDifferentiatorMutationVectorPreallocationCache = cached
+    }
+    return cached
+  }
+
   override fun enableDoubleMeasurementFixAndroid(): Boolean {
     var cached = enableDoubleMeasurementFixAndroidCache
     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<<db06b64a8d1b9ab99b368fea41185d62>>
+ * @generated SignedSource<<655d1ff3caeb3d8e95d44176d65b951b>>
  */
 
 /**
@@ -61,6 +61,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun enableDestroyShadowTreeRevisionAsync(): Boolean
 
+  @DoNotStrip public fun enableDifferentiatorMutationVectorPreallocation(): Boolean
+
   @DoNotStrip public fun enableDoubleMeasurementFixAndroid(): Boolean
 
   @DoNotStrip public fun enableEagerMainQueueModulesOnIOS(): 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<<0b95d68522d63d51d3e524aeecff246a>>
+ * @generated SignedSource<<175e48107d9bd1d713a4da0a252a58bf>>
  */
 
 /**
@@ -153,6 +153,12 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
+  bool enableDifferentiatorMutationVectorPreallocation() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableDifferentiatorMutationVectorPreallocation");
+    return method(javaProvider_);
+  }
+
   bool enableDoubleMeasurementFixAndroid() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableDoubleMeasurementFixAndroid");
@@ -648,6 +654,11 @@ bool JReactNativeFeatureFlagsCxxInterop::enableDestroyShadowTreeRevisionAsync(
   return ReactNativeFeatureFlags::enableDestroyShadowTreeRevisionAsync();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::enableDifferentiatorMutationVectorPreallocation(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::enableDifferentiatorMutationVectorPreallocation();
+}
+
 bool JReactNativeFeatureFlagsCxxInterop::enableDoubleMeasurementFixAndroid(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::enableDoubleMeasurementFixAndroid();
@@ -1066,6 +1077,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "enableDestroyShadowTreeRevisionAsync",
         JReactNativeFeatureFlagsCxxInterop::enableDestroyShadowTreeRevisionAsync),
+      makeNativeMethod(
+        "enableDifferentiatorMutationVectorPreallocation",
+        JReactNativeFeatureFlagsCxxInterop::enableDifferentiatorMutationVectorPreallocation),
       makeNativeMethod(
         "enableDoubleMeasurementFixAndroid",
         JReactNativeFeatureFlagsCxxInterop::enableDoubleMeasurementFixAndroid),

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<<6b7e2af51ba9d64ae4e474dfa104a7c3>>
+ * @generated SignedSource<<e182e4c23748be5ade70f6568ea2046f>>
  */
 
 /**
@@ -87,6 +87,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool enableDestroyShadowTreeRevisionAsync(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool enableDifferentiatorMutationVectorPreallocation(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static bool enableDoubleMeasurementFixAndroid(
     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<<08a361f2ffac6a0496adac1d4c3e4726>>
+ * @generated SignedSource<<5208616bc5d84f040ad0fa5e85acd6c4>>
  */
 
 /**
@@ -102,6 +102,10 @@ bool ReactNativeFeatureFlags::enableDestroyShadowTreeRevisionAsync() {
   return getAccessor().enableDestroyShadowTreeRevisionAsync();
 }
 
+bool ReactNativeFeatureFlags::enableDifferentiatorMutationVectorPreallocation() {
+  return getAccessor().enableDifferentiatorMutationVectorPreallocation();
+}
+
 bool ReactNativeFeatureFlags::enableDoubleMeasurementFixAndroid() {
   return getAccessor().enableDoubleMeasurementFixAndroid();
 }

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<<0bbe4d41581432dfad7adbc2db133d00>>
+ * @generated SignedSource<<1cbe2158c5242b2980ddafafe9084d7c>>
  */
 
 /**
@@ -134,6 +134,11 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool enableDestroyShadowTreeRevisionAsync();
 
+  /**
+   * Pre-allocate mutation vectors in the Differentiator to reduce reallocation overhead during shadow view diffing.
+   */
+  RN_EXPORT static bool enableDifferentiatorMutationVectorPreallocation();
+
   /**
    * When enabled a subset of components will avoid double measurement on Android.
    */