From f69153f25cfd9905b1de0a6c39cd776e06e3a8ec Mon Sep 17 00:00:00 2001
From: Marc Rousavy <me@mrousavy.com>
Date: Mon, 17 Feb 2025 05:18:46 -0800
Subject: [PATCH 1/2] RNGP - Add option to disable bundle compression (was:
 Make all React Native apps start 12% faster) (#49449)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Summary:
Okay the title is a bit clickbaity, but this is actually true. (on Android)

We (Janic, Szymon, Ruby and Me) discovered something interesting. React Native uses `mmap` for mapping the JS bundle to RAM, to avoid having to load the entire thing instantly at app startup.
Ruby doubted that this was true - so we investigated.

Apparently on Android, resources are **compressed**. And if the JS bundle is stored compressed, it has to be uncompressed before it can be loaded into RAM, hence not allowing it to be mmapp'ed! (see [`_CompressedAsset::getBuffer`](https://cs.android.com/android/platform/superproject/+/master:frameworks/base/libs/androidfw/Asset.cpp;l=903?q=Asset.cpp))

So with this PR, we now add `.bundle` files to `noCompress` in the react-native gradle plugin, which disables compression for the JS bundle.

In our tests, **this improved TTI by 400ms!! (or 12%)** 🤯🚀

NOTE: Yes, the .apk will now be bigger. But; Google Play compresses it anyways, so the **download size** of your .apk will likely not increase by much. It will be bigger on disk though.

## Changelog:

[ANDROID] [CHANGED] Add option to disable bundle compression to improve startup time

<!-- Help reviewers and the release process by writing your own changelog entry.

Pick one each for the category and type tags:

[ANDROID|GENERAL|IOS|INTERNAL] [BREAKING|ADDED|CHANGED|DEPRECATED|REMOVED|FIXED|SECURITY] - Message

For more details, see:
https://reactnative.dev/contributing/changelogs-in-pull-requests

Pull Request resolved: https://github.com/facebook/react-native/pull/49449

Test Plan:
### 1. Verify compression is disabled

Build two apps, one with this patch and one without. When I did this using the RN community template, the one without this patch was 47,6 MB, and the one with this patch was 48 MB in size. So the .apk got bigger, which is what we expected

### 2. Verify app startup is faster

Use tools like react-native-performance or custom markers to measure TTI. In our tests, we shaved off 400ms from the startup time, which was about 12%. (on a low-end Android device)

Reviewed By: javache, cipolleschi

Differential Revision: D69742221

Pulled By: cortinico
---
 .../kotlin/com/facebook/react/ReactExtension.kt     |  8 ++++++++
 .../main/kotlin/com/facebook/react/ReactPlugin.kt   | 13 +++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/packages/gradle-plugin/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactExtension.kt b/packages/gradle-plugin/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactExtension.kt
index b67e8826b339..a06c5b5d41a2 100644
--- a/packages/gradle-plugin/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactExtension.kt
+++ b/packages/gradle-plugin/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactExtension.kt
@@ -76,6 +76,14 @@ abstract class ReactExtension @Inject constructor(val project: Project) {
   val bundleAssetName: Property<String> =
       objects.property(String::class.java).convention("index.android.bundle")
 
+  /**
+   * Whether the Bundle Asset should be compressed when packaged into a `.apk`, or not. Disabling
+   * compression for the `.bundle` allows it to be directly memory-mapped to RAM, hence improving
+   * startup time - at the cost of a larger resulting `.apk` size.
+   */
+  val enableBundleCompression: Property<Boolean> =
+      objects.property(Boolean::class.java).convention(false)
+
   /**
    * Toggles the .so Cleanup step. If enabled, we will clean up all the unnecessary files before the
    * bundle task. If disabled, the developers will have to manually cleanup the files. Default: true
diff --git a/packages/gradle-plugin/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactPlugin.kt b/packages/gradle-plugin/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactPlugin.kt
index 9cf504539e2e..3ab7aabef971 100644
--- a/packages/gradle-plugin/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactPlugin.kt
+++ b/packages/gradle-plugin/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactPlugin.kt
@@ -7,6 +7,7 @@
 
 package com.facebook.react
 
+import com.android.build.api.dsl.ApplicationExtension
 import com.android.build.api.variant.AndroidComponentsExtension
 import com.android.build.gradle.internal.tasks.factory.dependsOn
 import com.facebook.react.internal.PrivateReactExtension
@@ -81,6 +82,7 @@ class ReactPlugin : Plugin<Project> {
       }
       configureAutolinking(project, extension)
       configureCodegen(project, extension, rootExtension, isLibrary = false)
+      configureResources(project, extension)
     }
 
     // Library Only Configuration
@@ -110,6 +112,17 @@ class ReactPlugin : Plugin<Project> {
     }
   }
 
+  /** This function configures Android resources - in this case just the bundle */
+  private fun configureResources(project: Project, reactExtension: ReactExtension) {
+    if (!reactExtension.enableBundleCompression.get()) {
+      // Bundle should not be compressed; add it to noCompress blacklist.
+      val bundleFileName = reactExtension.bundleAssetName.get()
+      val bundleFileExtension = bundleFileName.substringAfterLast('.', "")
+      val android = project.extensions.getByType(ApplicationExtension::class.java)
+      android.androidResources.noCompress.add(bundleFileExtension)
+    }
+  }
+
   /** This function sets up `react-native-codegen` in our Gradle plugin. */
   @Suppress("UnstableApiUsage")
   private fun configureCodegen(

From 7d95cfb1eb2bb6ef46173eaa0feb8868b2c6741f Mon Sep 17 00:00:00 2001
From: Nicola Corti <ncor@meta.com>
Date: Mon, 17 Feb 2025 11:02:19 -0800
Subject: [PATCH 2/2] Setup a Macrobenchmark for RNTester

Summary:
Tests have been executed with Android Studio:

**Startup**
```
# BEFORE

timeToInitialDisplayMs   min 216.9,   median 222.9,   max 245.3
Traces: Iteration 0 1 2 3 4 5 6 7 8 9

# AFTER

timeToInitialDisplayMs   min 213.8,   median 220.4,   max 237.9
Traces: Iteration 0 1 2 3 4 5 6 7 8 9
```

**APK size**
```
-rw-r--r--    1 ncor  staff  20087367 Feb 17 17:37 before.apk
-rw-r--r--    1 ncor  staff  20087399 Feb 17 18:43 after.apk
```

Changelog:
[Internal] [Changed] -

Differential Revision: D69753053
---
 build.gradle.kts                              |   1 +
 .../react-native/gradle/libs.versions.toml    |   9 +
 .../android/app/benchmark/.gitignore          |   1 +
 .../android/app/benchmark/build.gradle.kts    |  52 ++++++
 .../benchmark/src/main/AndroidManifest.xml    |   1 +
 .../benchmark/ExampleStartupBenchmark.kt      |  45 +++++
 .../rn-tester/android/app/build.gradle.kts    |  10 +-
 .../android/app/src/main/AndroidManifest.xml  | 169 +++++++++---------
 settings.gradle.kts                           |   2 +
 9 files changed, 209 insertions(+), 81 deletions(-)
 create mode 100644 packages/rn-tester/android/app/benchmark/.gitignore
 create mode 100644 packages/rn-tester/android/app/benchmark/build.gradle.kts
 create mode 100644 packages/rn-tester/android/app/benchmark/src/main/AndroidManifest.xml
 create mode 100644 packages/rn-tester/android/app/benchmark/src/main/java/com/example/benchmark/ExampleStartupBenchmark.kt

diff --git a/build.gradle.kts b/build.gradle.kts
index e71219373530..0227a891c3b5 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -12,6 +12,7 @@ plugins {
   alias(libs.plugins.download) apply false
   alias(libs.plugins.kotlin.android) apply false
   alias(libs.plugins.binary.compatibility.validator) apply true
+  alias(libs.plugins.android.test) apply false
 }
 
 val reactAndroidProperties = java.util.Properties()
diff --git a/packages/react-native/gradle/libs.versions.toml b/packages/react-native/gradle/libs.versions.toml
index 6216e087a713..dbae5d4284a4 100644
--- a/packages/react-native/gradle/libs.versions.toml
+++ b/packages/react-native/gradle/libs.versions.toml
@@ -42,6 +42,10 @@ fmt="11.0.2"
 folly="2024.11.18.00"
 glog="0.3.5"
 gtest="1.12.1"
+junitVersion = "1.2.1"
+espressoCore = "3.6.1"
+uiautomator = "2.3.0"
+benchmarkMacroJunit4 = "1.3.3"
 
 [libraries]
 androidx-appcompat = { module = "androidx.appcompat:appcompat", version.ref = "androidx-appcompat" }
@@ -76,6 +80,10 @@ mockito = {module = "org.mockito:mockito-inline", version.ref = "mockito" }
 mockito-kotlin = {module = "org.mockito.kotlin:mockito-kotlin", version.ref = "mockito-kotlin" }
 robolectric = {module = "org.robolectric:robolectric", version.ref = "robolectric" }
 thoughtworks = {module = "com.thoughtworks.xstream:xstream", version.ref = "xstream" }
+androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitVersion" }
+androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
+androidx-uiautomator = { group = "androidx.test.uiautomator", name = "uiautomator", version.ref = "uiautomator" }
+androidx-benchmark-macro-junit4 = { group = "androidx.benchmark", name = "benchmark-macro-junit4", version.ref = "benchmarkMacroJunit4" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }
@@ -84,3 +92,4 @@ download = { id = "de.undercouch.download", version.ref = "download" }
 nexus-publish = { id = "io.github.gradle-nexus.publish-plugin", version.ref = "nexus-publish" }
 kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
 binary-compatibility-validator = { id = "org.jetbrains.kotlinx.binary-compatibility-validator", version.ref = "binary-compatibility-validator" }
+android-test = { id = "com.android.test", version.ref = "agp" }
diff --git a/packages/rn-tester/android/app/benchmark/.gitignore b/packages/rn-tester/android/app/benchmark/.gitignore
new file mode 100644
index 000000000000..796b96d1c402
--- /dev/null
+++ b/packages/rn-tester/android/app/benchmark/.gitignore
@@ -0,0 +1 @@
+/build
diff --git a/packages/rn-tester/android/app/benchmark/build.gradle.kts b/packages/rn-tester/android/app/benchmark/build.gradle.kts
new file mode 100644
index 000000000000..d52ac7196534
--- /dev/null
+++ b/packages/rn-tester/android/app/benchmark/build.gradle.kts
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+plugins {
+  alias(libs.plugins.android.test)
+  alias(libs.plugins.kotlin.android)
+}
+
+android {
+  namespace = "com.example.benchmark"
+  compileSdk = 35
+
+  defaultConfig {
+    minSdk = 24
+    targetSdk = 35
+
+    testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+  }
+
+  buildTypes {
+    // This benchmark buildType is used for benchmarking, and should function like your
+    // release build (for example, with minification on). It"s signed with a debug key
+    // for easy local/CI testing.
+    create("benchmark") {
+      isDebuggable = true
+      signingConfig = getByName("debug").signingConfig
+      matchingFallbacks += listOf("release")
+    }
+  }
+
+  flavorDimensions += listOf("vm")
+  productFlavors {
+    create("hermes") { dimension = "vm" }
+    create("jsc") { dimension = "vm" }
+  }
+
+  targetProjectPath = ":packages:rn-tester:android:app"
+  experimentalProperties["android.experimental.self-instrumenting"] = true
+}
+
+dependencies {
+  implementation(libs.androidx.junit)
+  implementation(libs.androidx.espresso.core)
+  implementation(libs.androidx.uiautomator)
+  implementation(libs.androidx.benchmark.macro.junit4)
+}
+
+androidComponents { beforeVariants(selector().all()) { it.enable = it.buildType == "benchmark" } }
diff --git a/packages/rn-tester/android/app/benchmark/src/main/AndroidManifest.xml b/packages/rn-tester/android/app/benchmark/src/main/AndroidManifest.xml
new file mode 100644
index 000000000000..227314eeb7de
--- /dev/null
+++ b/packages/rn-tester/android/app/benchmark/src/main/AndroidManifest.xml
@@ -0,0 +1 @@
+<manifest />
\ No newline at end of file
diff --git a/packages/rn-tester/android/app/benchmark/src/main/java/com/example/benchmark/ExampleStartupBenchmark.kt b/packages/rn-tester/android/app/benchmark/src/main/java/com/example/benchmark/ExampleStartupBenchmark.kt
new file mode 100644
index 000000000000..97ead405a39a
--- /dev/null
+++ b/packages/rn-tester/android/app/benchmark/src/main/java/com/example/benchmark/ExampleStartupBenchmark.kt
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.example.benchmark
+
+import androidx.benchmark.macro.StartupMode
+import androidx.benchmark.macro.StartupTimingMetric
+import androidx.benchmark.macro.junit4.MacrobenchmarkRule
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+/**
+ * This is an example startup benchmark.
+ *
+ * It navigates to the device's home screen, and launches the default activity.
+ *
+ * Before running this benchmark:
+ * 1) switch your app's active build variant in the Studio (affects Studio runs only)
+ * 2) add `<profileable android:shell="true" />` to your app's manifest, within the `<application>`
+ *    tag
+ *
+ * Run this benchmark from Studio to see startup measurements, and captured system traces for
+ * investigating your app's performance.
+ */
+@RunWith(AndroidJUnit4::class)
+class ExampleStartupBenchmark {
+  @get:Rule val benchmarkRule = MacrobenchmarkRule()
+
+  @Test
+  fun startup() =
+      benchmarkRule.measureRepeated(
+          packageName = "com.facebook.react.uiapp",
+          metrics = listOf(StartupTimingMetric()),
+          iterations = 10,
+          startupMode = StartupMode.COLD) {
+            pressHome()
+            startActivityAndWait()
+          }
+}
diff --git a/packages/rn-tester/android/app/build.gradle.kts b/packages/rn-tester/android/app/build.gradle.kts
index d7d263c303f8..b45f0a177989 100644
--- a/packages/rn-tester/android/app/build.gradle.kts
+++ b/packages/rn-tester/android/app/build.gradle.kts
@@ -62,7 +62,9 @@ react {
   /* Hermes Commands */
   //   The hermes compiler command to run. By default it is 'hermesc'
   hermesCommand = "$reactNativeDirPath/ReactAndroid/hermes-engine/build/hermes/bin/hermesc"
-  enableHermesOnlyInVariants = listOf("hermesDebug", "hermesRelease")
+  enableHermesOnlyInVariants = listOf("hermesDebug", "hermesRelease", "hermesBenchmark")
+
+  enableBundleCompression.set(false)
 
   autolinkLibrariesWithApp()
 }
@@ -142,6 +144,11 @@ android {
       proguardFiles(getDefaultProguardFile("proguard-android.txt"))
       signingConfig = signingConfigs.getByName("debug")
     }
+    create("benchmark") {
+      initWith(buildTypes.getByName("release"))
+      matchingFallbacks += listOf("release")
+      isDebuggable = false
+    }
   }
   sourceSets.named("main") {
     // SampleTurboModule.
@@ -165,6 +172,7 @@ dependencies {
   "jscImplementation"(jscFlavor)
 
   testImplementation(libs.junit)
+  implementation("androidx.profileinstaller:profileinstaller:1.4.1")
 }
 
 android {
diff --git a/packages/rn-tester/android/app/src/main/AndroidManifest.xml b/packages/rn-tester/android/app/src/main/AndroidManifest.xml
index 720b58f79675..0783a82713fb 100644
--- a/packages/rn-tester/android/app/src/main/AndroidManifest.xml
+++ b/packages/rn-tester/android/app/src/main/AndroidManifest.xml
@@ -1,88 +1,97 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools">
 
-  <uses-feature
-    android:name="android.software.leanback"
-    android:required="false" />
-  <uses-feature
-    android:name="android.hardware.touchscreen"
-    android:required="false" />
-  <uses-feature
-    android:name="android.hardware.location.gps"
-    android:required="false" />
-  <uses-feature
-    android:name="android.hardware.camera"
-    android:required="false" />
+    <uses-feature
+        android:name="android.software.leanback"
+        android:required="false" />
+    <uses-feature
+        android:name="android.hardware.touchscreen"
+        android:required="false" />
+    <uses-feature
+        android:name="android.hardware.location.gps"
+        android:required="false" />
+    <uses-feature
+        android:name="android.hardware.camera"
+        android:required="false" />
 
-  <uses-permission android:name="android.permission.INTERNET" />
-  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
-  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
-  <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
-  <uses-permission android:name="android.permission.VIBRATE"/>
-  <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
+    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
+    <uses-permission android:name="android.permission.VIBRATE" />
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> <!-- Just to show permissions example -->
+    <uses-permission android:name="android.permission.CAMERA" />
+    <uses-permission android:name="android.permission.READ_CALENDAR" />
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
 
-  <!--Just to show permissions example-->
-  <uses-permission android:name="android.permission.CAMERA"/>
-  <uses-permission android:name="android.permission.READ_CALENDAR"/>
-  <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
+    <queries>
+        <package android:name="com.facebook.katana" />
+        <package android:name="com.facebook.lite" />
+        <package android:name="com.facebook.android" />
 
-  <!--
-  android:icon is used to display launcher icon on mobile devices.
-  android:banner is used to display a rectangular banned launcher icon on Android TV devices.
-  -->
-  <application
-      android:name=".RNTesterApplication"
-      android:allowBackup="true"
-      android:banner="@drawable/tv_banner"
-      android:icon="@mipmap/ic_launcher"
-      android:roundIcon="@mipmap/ic_launcher_round"
-      android:label="@string/app_name"
-      android:theme="@style/AppTheme"
-      android:supportsRtl="true">
-    <activity
-        android:name=".RNTesterActivity"
+        <intent>
+            <action android:name="android.intent.action.VIEW" />
+
+            <category android:name="android.intent.category.BROWSABLE" />
+
+            <data android:scheme="https" />
+        </intent>
+        <intent>
+            <action android:name="android.intent.action.VIEW" />
+
+            <data android:scheme="geo" />
+        </intent>
+        <intent>
+            <action android:name="android.intent.action.DIAL" />
+
+            <data android:scheme="tel" />
+        </intent>
+    </queries>
+
+    <application
+        android:name=".RNTesterApplication"
+        android:allowBackup="true"
+        android:banner="@drawable/tv_banner"
+        android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
-        android:screenOrientation="fullSensor"
-        android:launchMode="singleTask"
-        android:configChanges="orientation|screenSize|uiMode"
-        android:exported="true">
-      <intent-filter>
-        <action android:name="android.intent.action.MAIN" />
-        <category android:name="android.intent.category.LAUNCHER" />
-        <!-- Needed to properly create a launch intent when running on Android TV -->
-        <category android:name="android.intent.category.LEANBACK_LAUNCHER" />
-      </intent-filter>
-      <intent-filter>
-        <action android:name="android.intent.action.VIEW" />
-        <category android:name="android.intent.category.DEFAULT" />
-        <category android:name="android.intent.category.BROWSABLE" />
-        <!-- Accepts URIs that begin with "rntester://example” -->
-        <data android:scheme="rntester" android:host="example" />
-      </intent-filter>
-    </activity>
-    <provider
-      android:name="com.facebook.react.modules.blob.BlobProvider"
-      android:authorities="@string/blob_provider_authority"
-      android:exported="false"
-    />
-  </application>
-  <queries>
-    <package android:name="com.facebook.katana" />
-    <package android:name="com.facebook.lite" />
-    <package android:name="com.facebook.android" />
-    <intent>
-      <action android:name="android.intent.action.VIEW" />
-      <category android:name="android.intent.category.BROWSABLE" />
-      <data android:scheme="https" />
-    </intent>
-    <intent>
-      <action android:name="android.intent.action.VIEW" />
-      <data android:scheme="geo" />
-    </intent>
-    <intent>
-      <action android:name="android.intent.action.DIAL" />
-      <data android:scheme="tel" />
-    </intent>
-  </queries>
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/AppTheme">
+        <profileable
+            android:shell="true"
+            tools:targetApi="29" />
+
+        <activity
+            android:name=".RNTesterActivity"
+            android:configChanges="orientation|screenSize|uiMode"
+            android:exported="true"
+            android:label="@string/app_name"
+            android:launchMode="singleTask"
+            android:screenOrientation="fullSensor">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+                <!-- Needed to properly create a launch intent when running on Android TV -->
+                <category android:name="android.intent.category.LEANBACK_LAUNCHER" />
+            </intent-filter>
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <!-- Accepts URIs that begin with "rntester://example” -->
+                <data
+                    android:host="example"
+                    android:scheme="rntester" />
+            </intent-filter>
+        </activity>
+
+        <provider
+            android:name="com.facebook.react.modules.blob.BlobProvider"
+            android:authorities="@string/blob_provider_authority"
+            android:exported="false" />
+    </application>
 
 </manifest>
diff --git a/settings.gradle.kts b/settings.gradle.kts
index 4a6e16a5aeaa..8d22d7f38c63 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -39,3 +39,5 @@ configure<com.facebook.react.ReactSettingsExtension> {
   autolinkLibrariesFromCommand(
       workingDirectory = file("packages/rn-tester/"), lockFiles = files("yarn.lock"))
 }
+
+include(":packages:rn-tester:android:app:benchmark")