RNGP - Add option to disable bundle compression (was: Make all React Native apps start 12% faster)

packages/gradle-plugin/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactExtension.kt

@@ -76,6 +76,16 @@ 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.
+   * 
+   * Default: false
+   */
+  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

packages/gradle-plugin/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactPlugin.kt

@@ -81,6 +81,7 @@ class ReactPlugin : Plugin<Project> {
       }
       configureAutolinking(project, extension)
       configureCodegen(project, extension, rootExtension, isLibrary = false)
+      configureResources(project, extension)
     }
 
     // Library Only Configuration
@@ -110,6 +111,16 @@ class ReactPlugin : Plugin<Project> {
     }
   }
 
+  /** This function configures Android resources - in this case just the bundle */
+  private fun configureResources(project: Project, reactExtension: ReactExtension) {
+    project.extensions.getByType(AndroidComponentsExtension::class.java).finalizeDsl { ext ->
+      val bundleFileExtension = reactExtension.bundleAssetName.get().substringAfterLast('.', "")
+      if (!reactExtension.enableBundleCompression.get() && bundleFileExtension.isNotBlank()) {
+        ext.androidResources.noCompress.add(bundleFileExtension)
+      }
+    }
+  }
+
   /** This function sets up `react-native-codegen` in our Gradle plugin. */
   @Suppress("UnstableApiUsage")
   private fun configureCodegen(