Action for resource shrinking with aapt2

Introduces the ResourcesZip class to more easily handle processing merged resources.

RELNOTES: None
PiperOrigin-RevId: 169622715

1 files changed, 184 insertions, 0 deletions

diff --git a/src/tools/android/java/com/google/devtools/build/android/ResourcesZip.java b/src/tools/android/java/com/google/devtools/build/android/ResourcesZip.java
new file mode 100644
index 0000000000..e5436ad388
--- /dev/null
+++ b/src/tools/android/java/com/google/devtools/build/android/ResourcesZip.java
@@ -0,0 +1,184 @@
+// Copyright 2017 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package com.google.devtools.build.android;
+
+import static com.google.common.base.Predicates.not;
+
+import com.android.build.gradle.tasks.ResourceUsageAnalyzer;
+import com.google.common.collect.ImmutableList;
+import com.google.common.io.ByteStreams;
+import com.google.devtools.build.android.AndroidResourceOutputs.ZipBuilder;
+import com.google.devtools.build.android.AndroidResourceOutputs.ZipBuilderVisitor;
+import com.google.devtools.build.android.aapt2.CompiledResources;
+import com.google.devtools.build.android.aapt2.ResourceCompiler;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.ExecutionException;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
+import javax.annotation.Nullable;
+import javax.xml.parsers.ParserConfigurationException;
+import org.xml.sax.SAXException;
+
+/** Represents a collection of raw, merged resources with an optional id list. */
+public class ResourcesZip {
+
+  private final Path resourcesRoot;
+  private final Path assetsRoot;
+  private final Optional<Path> ids;
+
+  private ResourcesZip(Path resourcesRoot, Path assetsRoot, Optional<Path> ids) {
+    this.resourcesRoot = resourcesRoot;
+    this.assetsRoot = assetsRoot;
+    this.ids = ids;
+  }
+
+  /**
+   * @param resourcesRoot The root of the raw resources.
+   * @param assetsRoot The root of the raw assets.
+   */
+  public static ResourcesZip from(Path resourcesRoot, Path assetsRoot) {
+    return new ResourcesZip(resourcesRoot, assetsRoot, Optional.empty());
+  }
+
+  /**
+   * @param resourcesRoot The root of the raw resources.
+   * @param assetsRoot The root of the raw assets.
+   * @param resourceIds Optional path to a file containing the resource ids.
+   */
+  public static ResourcesZip from(Path resourcesRoot, Path assetsRoot, Path resourceIds) {
+    return new ResourcesZip(
+        resourcesRoot, assetsRoot, Optional.of(resourceIds).filter(Files::exists));
+  }
+
+  /** Creates a ResourcesZip from an archive by expanding into the workingDirectory. */
+  public static ResourcesZip createFrom(Path resourcesZip, Path workingDirectory)
+      throws IOException {
+    // Expand resource files zip into working directory.
+    final ZipFile zipFile = new ZipFile(resourcesZip.toFile());
+
+    zipFile
+        .stream()
+        .filter(not(ZipEntry::isDirectory))
+        .forEach(
+            entry -> {
+              Path output = workingDirectory.resolve(entry.getName());
+              try {
+                Files.createDirectories(output.getParent());
+                try (FileOutputStream fos = new FileOutputStream(output.toFile())) {
+                  ByteStreams.copy(zipFile.getInputStream(entry), fos);
+                }
+              } catch (IOException e) {
+                throw new RuntimeException(e);
+              }
+            });
+    return from(
+        Files.createDirectories(workingDirectory.resolve("res")),
+        Files.createDirectories(workingDirectory.resolve("assets")),
+        workingDirectory.resolve("ids.txt"));
+  }
+
+  /**
+   * Creates a zip file containing the provided android resources and assets.
+   *
+   * @param output The path to write the zip file
+   * @param compress Whether or not to compress the content
+   * @throws IOException
+   */
+  public void writeTo(Path output, boolean compress) throws IOException {
+    try (final ZipBuilder zip = ZipBuilder.createFor(output)) {
+      if (Files.exists(resourcesRoot)) {
+        ZipBuilderVisitor visitor = new ZipBuilderVisitor(zip, resourcesRoot, "res");
+        visitor.setCompress(compress);
+        Files.walkFileTree(resourcesRoot, visitor);
+        if (!Files.exists(resourcesRoot.resolve("values/public.xml"))) {
+          // add an empty public xml, if one doesn't exist. The ResourceUsageAnalyzer expects one.
+          visitor.addEntry(
+              resourcesRoot.resolve("values").resolve("public.xml"),
+              "<resources></resources>".getBytes(StandardCharsets.UTF_8));
+        }
+        visitor.writeEntries();
+      }
+      if (Files.exists(assetsRoot)) {
+        ZipBuilderVisitor visitor = new ZipBuilderVisitor(zip, assetsRoot, "assets");
+        visitor.setCompress(compress);
+        Files.walkFileTree(assetsRoot, visitor);
+        visitor.writeEntries();
+      }
+
+      ids.ifPresent(
+          p -> {
+            try {
+              zip.addEntry("ids.txt", Files.readAllBytes(p), ZipEntry.STORED);
+            } catch (IOException e) {
+              throw new RuntimeException(e);
+            }
+          });
+    }
+  }
+
+  /** Removes unused resources from the archived resources. */
+  public ShrunkResources shrink(
+      Set<String> packages,
+      Path rTxt,
+      Path classJar,
+      Path manifest,
+      @Nullable Path proguardMapping,
+      Path logFile,
+      Path workingDirectory)
+      throws ParserConfigurationException, IOException, SAXException {
+
+    new ResourceUsageAnalyzer(
+            packages, rTxt, classJar, manifest, proguardMapping, resourcesRoot, logFile)
+        .shrink(workingDirectory);
+    return ShrunkResources.of(
+        new ResourcesZip(workingDirectory, assetsRoot, ids),
+        new UnvalidatedAndroidData(
+            ImmutableList.of(workingDirectory), ImmutableList.of(assetsRoot), manifest));
+  }
+
+  static class ShrunkResources {
+
+    private ResourcesZip resourcesZip;
+    private UnvalidatedAndroidData unvalidatedAndroidData;
+
+    private ShrunkResources(
+        ResourcesZip resourcesZip, UnvalidatedAndroidData unvalidatedAndroidData) {
+      this.resourcesZip = resourcesZip;
+      this.unvalidatedAndroidData = unvalidatedAndroidData;
+    }
+
+    public static ShrunkResources of(
+        ResourcesZip resourcesZip, UnvalidatedAndroidData unvalidatedAndroidData) {
+      return new ShrunkResources(resourcesZip, unvalidatedAndroidData);
+    }
+
+    public ShrunkResources writeArchiveTo(Path archivePath, boolean compress) throws IOException {
+      resourcesZip.writeTo(archivePath, compress);
+      return this;
+    }
+
+    public CompiledResources compile(ResourceCompiler compiler, Path workingDirectory)
+        throws InterruptedException, ExecutionException, IOException {
+      return unvalidatedAndroidData
+          .compile(compiler, workingDirectory)
+          .addStableIds(resourcesZip.ids);
+    }
+  }
+}