Prevent class loading for lazy native modules

Summary:
When native modules use `LazyReactPackage`, the modules themselves are not initialized. However, they still use the class names, causing the classes to load. This diff removes the need to perform any class loads. Any properties of the classes that are required are now populated in the `ReactModuleInfo` of that class.

Note that this diff itself does not prevent class loading since any references to `*.class` in `LazyReactpackage` needs to be removed in a consequent diff

Reviewed By: achen1

Differential Revision: D8950025

fbshipit-source-id: 80ddf7e1f33bf2af0db1bd262069795de77ec611

ReactAndroid/src/main/java/com/facebook/react/bridge/JavaModuleWrapper.java

@@ -49,14 +49,14 @@ public class JavaModuleWrapper {
 
   private final JSInstance mJSInstance;
   private final ModuleHolder mModuleHolder;
-  private final Class<? extends NativeModule> mModuleClass;
+  private final String mClassName;
   private final ArrayList<NativeModule.NativeMethod> mMethods;
   private final ArrayList<MethodDescriptor> mDescs;
 
-  public JavaModuleWrapper(JSInstance jsInstance, Class<? extends NativeModule> moduleClass, ModuleHolder moduleHolder) {
+  public JavaModuleWrapper(JSInstance jsInstance, String className, ModuleHolder moduleHolder) {
     mJSInstance = jsInstance;
     mModuleHolder = moduleHolder;
-    mModuleClass = moduleClass;
+    mClassName = className;
     mMethods = new ArrayList<>();
     mDescs = new ArrayList();
   }
@@ -76,9 +76,9 @@ public class JavaModuleWrapper {
     Systrace.beginSection(TRACE_TAG_REACT_JAVA_BRIDGE, "findMethods");
     Set<String> methodNames = new HashSet<>();
 
-    Class<? extends NativeModule> classForMethods = mModuleClass;
+    Class<? extends NativeModule> classForMethods = mModuleHolder.getModule().getClass();
     Class<? extends NativeModule> superClass =
-        (Class<? extends NativeModule>) mModuleClass.getSuperclass();
+        (Class<? extends NativeModule>) classForMethods.getSuperclass();
     if (ReactModuleWithSpec.class.isAssignableFrom(superClass)) {
       // For java module that is based on generated flow-type spec, inspect the
       // spec abstract class instead, which is the super class of the given java

ReactAndroid/src/main/java/com/facebook/react/bridge/ModuleHolder.java

@@ -40,6 +40,8 @@ public class ModuleHolder {
   private final String mName;
   private final boolean mCanOverrideExistingModule;
   private final boolean mHasConstants;
+  private final boolean mIsCxxModule;
+  private final boolean mHasOnBatchCompleteListener;
 
   private @Nullable Provider<? extends NativeModule> mProvider;
   // Outside of the constructur, these should only be checked or set when synchronized on this
@@ -55,6 +57,8 @@ public class ModuleHolder {
     mCanOverrideExistingModule = moduleInfo.canOverrideExistingModule();
     mHasConstants = moduleInfo.hasConstants();
     mProvider = provider;
+    mHasOnBatchCompleteListener = moduleInfo.hasOnBatchCompleteListener();
+    mIsCxxModule = moduleInfo.isCxxModule();
     if (moduleInfo.needsEagerInit()) {
       mModule = create();
     }
@@ -64,6 +68,8 @@ public class ModuleHolder {
     mName = nativeModule.getName();
     mCanOverrideExistingModule = nativeModule.canOverrideExistingModule();
     mHasConstants = true;
+    mIsCxxModule = CxxModuleWrapper.class.isAssignableFrom(nativeModule.getClass());
+    mHasOnBatchCompleteListener = OnBatchCompleteListener.class.isAssignableFrom(nativeModule.getClass());
     mModule = nativeModule;
     PrinterHolder.getPrinter()
         .logMessage(ReactDebugOverlayTags.NATIVE_MODULE, "NativeModule init: %s", mName);
@@ -113,6 +119,10 @@ public class ModuleHolder {
     return mHasConstants;
   }
 
+  public boolean isCxxModule() {return mIsCxxModule; }
+
+  public boolean hasOnBatchCompleteListener() {return mHasOnBatchCompleteListener; }
+
   @DoNotStrip
   public NativeModule getModule() {
     NativeModule module;

ReactAndroid/src/main/java/com/facebook/react/bridge/ModuleSpec.java

@@ -25,6 +25,7 @@ public class ModuleSpec {
 
   private final @Nullable Class<? extends NativeModule> mType;
   private final Provider<? extends NativeModule> mProvider;
+  private final String mClassName;
 
   /**
    * Simple spec for modules with a default constructor.
@@ -66,19 +67,28 @@ public class ModuleSpec {
 
   public static ModuleSpec nativeModuleSpec(
       Class<? extends NativeModule> type, Provider<? extends NativeModule> provider) {
-    return new ModuleSpec(type, provider);
+    return new ModuleSpec(provider, type.getName());
   }
 
   private ModuleSpec(
       @Nullable Class<? extends NativeModule> type, Provider<? extends NativeModule> provider) {
     mType = type;
     mProvider = provider;
+    mClassName = type == null ? null : type.getName();
+  }
+
+  public ModuleSpec(Provider<? extends NativeModule> provider, String name) {
+    mType = null;
+    mProvider = provider;
+    mClassName = name;
   }
 
   public @Nullable Class<? extends NativeModule> getType() {
     return mType;
   }
 
+  public String getClassName(){return mClassName;}
+
   public Provider<? extends NativeModule> getProvider() {
     return mProvider;
   }

ReactAndroid/src/main/java/com/facebook/react/bridge/NativeModuleRegistry.java

@@ -22,12 +22,12 @@ import com.facebook.systrace.Systrace;
 public class NativeModuleRegistry {
 
   private final ReactApplicationContext mReactApplicationContext;
-  private final Map<Class<? extends NativeModule>, ModuleHolder> mModules;
+  private final Map<String, ModuleHolder> mModules;
   private final ArrayList<ModuleHolder> mBatchCompleteListenerModules;
 
   public NativeModuleRegistry(
     ReactApplicationContext reactApplicationContext,
-    Map<Class<? extends NativeModule>, ModuleHolder> modules,
+    Map<String, ModuleHolder> modules,
     ArrayList<ModuleHolder> batchCompleteListenerModules) {
     mReactApplicationContext = reactApplicationContext;
     mModules = modules;
@@ -37,7 +37,7 @@ public class NativeModuleRegistry {
   /**
    * Private getters for combining NativeModuleRegistrys
    */
-  private Map<Class<? extends NativeModule>, ModuleHolder> getModuleMap() {
+  private Map<String, ModuleHolder> getModuleMap() {
     return mModules;
   }
 
@@ -52,9 +52,10 @@ public class NativeModuleRegistry {
   /* package */ Collection<JavaModuleWrapper> getJavaModules(
       JSInstance jsInstance) {
     ArrayList<JavaModuleWrapper> javaModules = new ArrayList<>();
-    for (Map.Entry<Class<? extends NativeModule>, ModuleHolder> entry : mModules.entrySet()) {
-      Class<? extends NativeModule> type = entry.getKey();
-      if (!CxxModuleWrapperBase.class.isAssignableFrom(type)) {
+    for (Map.Entry<String, ModuleHolder> entry : mModules.entrySet()) {
+      String type = entry.getKey();
+      if (!entry.getValue().isCxxModule()) {
+      //if (!CxxModuleWrapperBase.class.isAssignableFrom(entry.getValue().getModule().getClass())) {
         javaModules.add(new JavaModuleWrapper(jsInstance, type, entry.getValue()));
       }
     }
@@ -63,9 +64,8 @@ public class NativeModuleRegistry {
 
   /* package */ Collection<ModuleHolder> getCxxModules() {
     ArrayList<ModuleHolder> cxxModules = new ArrayList<>();
-    for (Map.Entry<Class<? extends NativeModule>, ModuleHolder> entry : mModules.entrySet()) {
-      Class<?> type = entry.getKey();
-      if (CxxModuleWrapperBase.class.isAssignableFrom(type)) {
+    for (Map.Entry<String, ModuleHolder> entry : mModules.entrySet()) {
+      if (entry.getValue().isCxxModule()) {
         cxxModules.add(entry.getValue());
       }
     }
@@ -80,11 +80,11 @@ public class NativeModuleRegistry {
     Assertions.assertCondition(mReactApplicationContext.equals(newRegister.getReactApplicationContext()),
       "Extending native modules with non-matching application contexts.");
 
-    Map<Class<? extends NativeModule>, ModuleHolder> newModules = newRegister.getModuleMap();
+    Map<String, ModuleHolder> newModules = newRegister.getModuleMap();
     ArrayList<ModuleHolder> batchCompleteListeners = newRegister.getBatchCompleteListenerModules();
 
-    for (Map.Entry<Class<? extends NativeModule>, ModuleHolder> entry : newModules.entrySet()) {
-      Class<? extends NativeModule> key = entry.getKey();
+    for (Map.Entry<String, ModuleHolder> entry : newModules.entrySet()) {
+      String key = entry.getKey();
       if (!mModules.containsKey(key)) {
         ModuleHolder value = entry.getValue();
         if (batchCompleteListeners.contains(value)) {
@@ -137,12 +137,12 @@ public class NativeModuleRegistry {
   }
 
   public <T extends NativeModule> boolean hasModule(Class<T> moduleInterface) {
-    return mModules.containsKey(moduleInterface);
+    return mModules.containsKey(moduleInterface.getName());
   }
 
   public <T extends NativeModule> T getModule(Class<T> moduleInterface) {
     return (T) Assertions.assertNotNull(
-        mModules.get(moduleInterface), moduleInterface.getSimpleName()).getModule();
+        mModules.get(moduleInterface.getName()), moduleInterface.getSimpleName()).getModule();
   }
 
   public List<NativeModule> getAllModules() {