Rollback of commit bd40871283a54268945dcb0c47c0326645ffda18.

*** Reason for rollback ***

Rolling forward with the correct changes to the AndroidResourceMergingAction. Tested manually.

*** Original change description ***

Automated [] rollback of commit a58f245a4b40c0ef961b1f30d96b16a9349711c3.

*** Reason for rollback ***

broke over 100k targets, in the depot, see []

*** Original change description ***

Move library R generation to a separate action, ensuring the merging happens
off the java critical path.

--
PiperOrigin-RevId: 151087737
MOS_MIGRATED_REVID=151087737

1 files changed, 55 insertions, 3 deletions

diff --git a/src/tools/android/java/com/google/devtools/build/android/AndroidDataWriter.java b/src/tools/android/java/com/google/devtools/build/android/AndroidDataWriter.java
index 7b5f14d501..433620d144 100644
--- a/src/tools/android/java/com/google/devtools/build/android/AndroidDataWriter.java
+++ b/src/tools/android/java/com/google/devtools/build/android/AndroidDataWriter.java
@@ -28,6 +28,7 @@ import com.google.common.collect.Ordering;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.ListeningExecutorService;
 import com.google.common.util.concurrent.MoreExecutors;
+import com.google.devtools.build.android.AndroidResourceMergingAction.Options;
 import com.google.devtools.build.android.xml.Namespaces;
 import java.io.BufferedWriter;
 import java.io.File;
@@ -103,7 +104,7 @@ public class AndroidDataWriter implements AndroidDataWritingVisitor {
   private static final char[] START_RESOURCES_TAG = "<resources".toCharArray();
   public static final char[] END_RESOURCES = "</resources>".toCharArray();
   private static final char[] LINE_END = "\n".toCharArray();
-  private static final PngCruncher NOOP_CRUNCHER =
+  static final PngCruncher NOOP_CRUNCHER =
       new PngCruncher() {
         @Override
         public int start() {
@@ -111,8 +112,7 @@ public class AndroidDataWriter implements AndroidDataWritingVisitor {
         }
 
         @Override
-        public void end(int key) throws InterruptedException {
-        }
+        public void end(int key) throws InterruptedException {}
 
         @Override
         public void crunchPng(int key, @NonNull File source, @NonNull File destination)
@@ -126,6 +126,38 @@ public class AndroidDataWriter implements AndroidDataWritingVisitor {
         }
       };
 
+  /**
+   * The merged {@link Options#resourcesOutput} is only used for validation and not for running
+   * (unlike the final APK), so the image files do not need to be the true image files. We only need
+   * the filenames to be the same.
+   *
+   * <p>Thus, we only create empty files for PNGs (convenient with a custom PngCruncher object).
+   * This does miss out on other image files like .webp.
+   */
+  static final PngCruncher STUB_CRUNCHER =
+      new PngCruncher() {
+
+        @Override
+        public void crunchPng(int key, File from, File to) throws PngException {
+          try {
+            to.createNewFile();
+            if (!to.setLastModified(System.currentTimeMillis())) {
+              throw new PngException("Could not set milliseconds");
+            }
+          } catch (IOException e) {
+            throw new PngException(e);
+          }
+        }
+
+        @Override
+        public int start() {
+          return 0;
+        }
+
+        @Override
+        public void end(int key) {}
+      };
+
   private final Path destination;
 
   private final Map<String, ResourceValuesDefinitions> valueTags = new HashMap<>();
@@ -166,6 +198,26 @@ public class AndroidDataWriter implements AndroidDataWritingVisitor {
         NOOP_CRUNCHER,
         MoreExecutors.newDirectExecutorService());
   }
+  
+  /**
+   * Creates a new writer for processing android libraries.
+   *
+   * <p>This writer has stub png cruncher that touches empty files for png resources.
+   *
+   * @param manifestDirectory The base directory for the AndroidManifest.
+   * @param resourceDirectory The directory to copy resources into.
+   * @param assetsDirectory The directory to copy assets into.
+   * @param executorService An execution service for multi-threaded writing.
+   * @return A new {@link AndroidDataWriter}.
+   */
+  public static AndroidDataWriter createForLibrary(
+      Path manifestDirectory,
+      Path resourceDirectory,
+      Path assetsDirectory,
+      ListeningExecutorService executorService) {
+    return createWith(
+        manifestDirectory, resourceDirectory, assetsDirectory, STUB_CRUNCHER, executorService);
+  }
 
   /**
    * Creates a new writer.