Read loading unit mapping from AndroidManifest instead of strings

shell/platform/android/io/flutter/embedding/engine/deferredcomponents/PlayStoreDeferredComponentManager.java

@@ -6,9 +6,12 @@
 
 import android.annotation.SuppressLint;
 import android.content.Context;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.res.AssetManager;
 import android.os.Build;
+import android.os.Bundle;
 import android.util.SparseArray;
 import android.util.SparseIntArray;
 import androidx.annotation.NonNull;
@@ -53,6 +56,8 @@ public class PlayStoreDeferredComponentManager implements DeferredComponentManag
   private @NonNull SparseArray<String> sessionIdToState;
   private @NonNull Map<String, Integer> nameToSessionId;
 
+  protected @NonNull SparseArray<String> loadingUnitIdToModuleNames;
+
   private FeatureInstallStateUpdatedListener listener;
 
   private class FeatureInstallStateUpdatedListener implements SplitInstallStateUpdatedListener {
@@ -202,6 +207,9 @@ public PlayStoreDeferredComponentManager(
     sessionIdToLoadingUnitId = new SparseIntArray();
     sessionIdToState = new SparseArray<>();
     nameToSessionId = new HashMap<>();
+
+    loadingUnitIdToModuleNames = new SparseArray<>();
+    initLoadingUnitMappingToModuleNames();
   }
 
   public void setJNI(@NonNull FlutterJNI flutterJNI) {
@@ -222,19 +230,49 @@ public void setDeferredComponentChannel(DeferredComponentChannel channel) {
     this.channel = channel;
   }
 
-  private String loadingUnitIdToModuleName(int loadingUnitId) {
-    // Loading unit id to module name mapping stored in android Strings
-    // resources.
-    int moduleNameIdentifier =
-        context
-            .getResources()
-            .getIdentifier("loadingUnit" + loadingUnitId, "string", context.getPackageName());
-    return context.getResources().getString(moduleNameIdentifier);
+  @NonNull
+  private ApplicationInfo getApplicationInfo() {
+    try {
+      return context
+          .getPackageManager()
+          .getApplicationInfo(context.getPackageName(), PackageManager.GET_META_DATA);
+    } catch (NameNotFoundException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  // Obtain and parses the metadata string. An example encoded string is:
+  //
+  //    "2:module2,3:module3,4:module1"
+  //
+  // Where loading unit 2 is included in module2, loading unit 3 is
+  // included in module3, and loading unit 4 is included in module1.
+  private void initLoadingUnitMappingToModuleNames() {
+    String mappingKey = DeferredComponentManager.class.getName() + ".loadingUnitMapping";
+    ApplicationInfo applicationInfo = getApplicationInfo();
+    if (applicationInfo != null) {
+      Bundle metaData = applicationInfo.metaData;
+      if (metaData != null) {
+        String rawMappingString = metaData.getString(mappingKey, null);
+        if (rawMappingString == null) {
+          Log.e(
+              TAG,
+              "No loading unit to dynamic feature module name found. Ensure '"
+                  + mappingKey
+                  + "' is defined in the base module's AndroidManifest.");
+        } else {
+          for (String entry : rawMappingString.split(",")) {
+            String[] splitEntry = entry.split(":");
+            loadingUnitIdToModuleNames.put(Integer.parseInt(splitEntry[0]), splitEntry[1]);
+          }
+        }
+      }
+    }
   }
 
   public void installDeferredComponent(int loadingUnitId, String moduleName) {
     String resolvedModuleName =
-        moduleName != null ? moduleName : loadingUnitIdToModuleName(loadingUnitId);
+        moduleName != null ? moduleName : loadingUnitIdToModuleNames.get(loadingUnitId);
     if (resolvedModuleName == null) {
       Log.e(
           TAG,
@@ -297,7 +335,7 @@ public void installDeferredComponent(int loadingUnitId, String moduleName) {
 
   public String getDeferredComponentInstallState(int loadingUnitId, String moduleName) {
     String resolvedModuleName =
-        moduleName != null ? moduleName : loadingUnitIdToModuleName(loadingUnitId);
+        moduleName != null ? moduleName : loadingUnitIdToModuleNames.get(loadingUnitId);
     if (resolvedModuleName == null) {
       Log.e(
           TAG,
@@ -400,7 +438,7 @@ public void loadDartLibrary(int loadingUnitId, String moduleName) {
 
   public boolean uninstallDeferredComponent(int loadingUnitId, String moduleName) {
     String resolvedModuleName =
-        moduleName != null ? moduleName : loadingUnitIdToModuleName(loadingUnitId);
+        moduleName != null ? moduleName : loadingUnitIdToModuleNames.get(loadingUnitId);
     if (resolvedModuleName == null) {
       Log.e(
           TAG,
@@ -410,7 +448,9 @@ public boolean uninstallDeferredComponent(int loadingUnitId, String moduleName)
     List<String> modulesToUninstall = new ArrayList<>();
     modulesToUninstall.add(resolvedModuleName);
     splitInstallManager.deferredUninstall(modulesToUninstall);
-    sessionIdToState.delete(nameToSessionId.get(resolvedModuleName));
+    if (nameToSessionId.get(resolvedModuleName) != null) {
+      sessionIdToState.delete(nameToSessionId.get(resolvedModuleName));
+    }
     return true;
   }
 

shell/platform/android/test/io/flutter/embedding/engine/deferredcomponents/PlayStoreDeferredComponentManagerTest.java

@@ -5,6 +5,7 @@
 package io.flutter.embedding.engine.deferredcomponents;
 
 import static junit.framework.TestCase.assertEquals;
+import static junit.framework.TestCase.assertFalse;
 import static junit.framework.TestCase.assertTrue;
 import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.anyInt;
@@ -19,6 +20,7 @@
 import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.res.AssetManager;
 import android.os.Bundle;
+import android.util.SparseArray;
 import androidx.annotation.NonNull;
 import io.flutter.embedding.engine.FlutterJNI;
 import io.flutter.embedding.engine.loader.ApplicationInfoLoader;
@@ -70,6 +72,9 @@ public void deferredComponentInstallFailure(
   private class TestPlayStoreDeferredComponentManager extends PlayStoreDeferredComponentManager {
     public TestPlayStoreDeferredComponentManager(Context context, FlutterJNI jni) {
       super(context, jni);
+      loadingUnitIdToModuleNames = new SparseArray<>();
+      loadingUnitIdToModuleNames.put(5, "FakeModuleName5");
+      loadingUnitIdToModuleNames.put(2, "FakeModuleName2");
     }
 
     @Override
@@ -223,4 +228,16 @@ public void stateGetterReturnsUnknowByDefault() throws NameNotFoundException {
         new TestPlayStoreDeferredComponentManager(spyContext, jni);
     assertEquals(playStoreManager.getDeferredComponentInstallState(-1, "invalidName"), "unknown");
   }
+
+  @Test
+  public void loadingUnitMappingFindsMatch() throws NameNotFoundException {
+    TestFlutterJNI jni = new TestFlutterJNI();
+    Context spyContext = spy(RuntimeEnvironment.application);
+    TestPlayStoreDeferredComponentManager playStoreManager =
+        new TestPlayStoreDeferredComponentManager(spyContext, jni);
+
+    assertTrue(playStoreManager.uninstallDeferredComponent(5, null));
+    assertTrue(playStoreManager.uninstallDeferredComponent(2, null));
+    assertFalse(playStoreManager.uninstallDeferredComponent(3, null));
+  }
 }