Add function to return path for last resolved resource

After an AssetManager.FindEntry call is made, either directly or from any of the resource entry calls, a stack of the steps taken to resolve the resource is saved. Those steps can be retrieved as a log later on by calling AssetManager.GetLastResourceResolution, which returns a formatted string of the resource ID/name and path taken, including the configs and package names of each step.

Logging and the saving of the steps to memory can be enabled/disabled with the @hide .setResourceResolutionLoggingEnabled() method on AssetManager.

Bug: 122374289

Test: cases for single and multi ApkAssets loaded
Test: case for no resolution made
Test: made test app to display log on device
Test: added debugging call to source and ran through on-device apps

Change-Id: I6a32b8d4020c3f8510032ff7f431510089fff43f
diff --git a/libs/androidfw/tests/AssetManager2_test.cpp b/libs/androidfw/tests/AssetManager2_test.cpp
index 5449a54..105dcd2 100644
--- a/libs/androidfw/tests/AssetManager2_test.cpp
+++ b/libs/androidfw/tests/AssetManager2_test.cpp
@@ -586,4 +586,111 @@
   EXPECT_THAT(asset_dir->getFileType(2), Eq(FileType::kFileTypeDirectory));
 }
 
+TEST_F(AssetManager2Test, GetLastPathWithoutEnablingReturnsEmpty) {
+  ResTable_config desired_config;
+
+  AssetManager2 assetmanager;
+  assetmanager.SetConfiguration(desired_config);
+  assetmanager.SetApkAssets({basic_assets_.get()});
+  assetmanager.SetResourceResolutionLoggingEnabled(false);
+
+  Res_value value;
+  ResTable_config selected_config;
+  uint32_t flags;
+
+  ApkAssetsCookie cookie =
+      assetmanager.GetResource(basic::R::string::test1, false /*may_be_bag*/,
+                               0 /*density_override*/, &value, &selected_config, &flags);
+  ASSERT_NE(kInvalidCookie, cookie);
+
+  auto result = assetmanager.GetLastResourceResolution();
+  EXPECT_EQ("", result);
+}
+
+TEST_F(AssetManager2Test, GetLastPathWithoutResolutionReturnsEmpty) {
+  ResTable_config desired_config;
+
+  AssetManager2 assetmanager;
+  assetmanager.SetConfiguration(desired_config);
+  assetmanager.SetApkAssets({basic_assets_.get()});
+
+  auto result = assetmanager.GetLastResourceResolution();
+  EXPECT_EQ("", result);
+}
+
+TEST_F(AssetManager2Test, GetLastPathWithSingleApkAssets) {
+  ResTable_config desired_config;
+  memset(&desired_config, 0, sizeof(desired_config));
+  desired_config.language[0] = 'd';
+  desired_config.language[1] = 'e';
+
+  AssetManager2 assetmanager;
+  assetmanager.SetResourceResolutionLoggingEnabled(true);
+  assetmanager.SetConfiguration(desired_config);
+  assetmanager.SetApkAssets({basic_assets_.get()});
+
+  Res_value value;
+  ResTable_config selected_config;
+  uint32_t flags;
+
+  ApkAssetsCookie cookie =
+      assetmanager.GetResource(basic::R::string::test1, false /*may_be_bag*/,
+                               0 /*density_override*/, &value, &selected_config, &flags);
+  ASSERT_NE(kInvalidCookie, cookie);
+
+  auto result = assetmanager.GetLastResourceResolution();
+  EXPECT_EQ("Resolution for 0x7f030000 com.android.basic:string/test1\n\tFor config -de\n\tFound initial: com.android.basic", result);
+}
+
+TEST_F(AssetManager2Test, GetLastPathWithMultipleApkAssets) {
+  ResTable_config desired_config;
+  memset(&desired_config, 0, sizeof(desired_config));
+  desired_config.language[0] = 'd';
+  desired_config.language[1] = 'e';
+
+  AssetManager2 assetmanager;
+  assetmanager.SetResourceResolutionLoggingEnabled(true);
+  assetmanager.SetConfiguration(desired_config);
+  assetmanager.SetApkAssets({basic_assets_.get(), basic_de_fr_assets_.get()});
+
+  Res_value value = Res_value();
+  ResTable_config selected_config;
+  uint32_t flags;
+
+  ApkAssetsCookie cookie =
+      assetmanager.GetResource(basic::R::string::test1, false /*may_be_bag*/,
+                               0 /*density_override*/, &value, &selected_config, &flags);
+  ASSERT_NE(kInvalidCookie, cookie);
+
+  auto result = assetmanager.GetLastResourceResolution();
+  EXPECT_EQ("Resolution for 0x7f030000 com.android.basic:string/test1\n\tFor config -de\n\tFound initial: com.android.basic\n\tFound better: com.android.basic -de", result);
+}
+
+TEST_F(AssetManager2Test, GetLastPathAfterDisablingReturnsEmpty) {
+  ResTable_config desired_config;
+  memset(&desired_config, 0, sizeof(desired_config));
+
+  AssetManager2 assetmanager;
+  assetmanager.SetResourceResolutionLoggingEnabled(true);
+  assetmanager.SetConfiguration(desired_config);
+  assetmanager.SetApkAssets({basic_assets_.get()});
+
+  Res_value value = Res_value();
+  ResTable_config selected_config;
+  uint32_t flags;
+
+  ApkAssetsCookie cookie =
+      assetmanager.GetResource(basic::R::string::test1, false /*may_be_bag*/,
+                               0 /*density_override*/, &value, &selected_config, &flags);
+  ASSERT_NE(kInvalidCookie, cookie);
+
+  auto resultEnabled = assetmanager.GetLastResourceResolution();
+  ASSERT_NE("", resultEnabled);
+
+  assetmanager.SetResourceResolutionLoggingEnabled(false);
+
+  auto resultDisabled = assetmanager.GetLastResourceResolution();
+  EXPECT_EQ("", resultDisabled);
+}
+
 }  // namespace android