AAPT2: Rename strip phase to optimize

- Allow resource deduping, version collapsing, and sparse resource
  encoding.

Test: manual
Change-Id: Ia4aa892ab5b06ba1d5ea4a6efb51b00bc3a980c4

tools/aapt2/Android.bp

@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2015 The Android Open Source Project
+// Copyright (C) 2017 The Android Open Source Project
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -19,7 +19,7 @@ toolSources = [
     "diff/Diff.cpp",
     "dump/Dump.cpp",
     "link/Link.cpp",
-    "strip/Strip.cpp",
+    "optimize/Optimize.cpp",
 ]
 
 cc_defaults {
@@ -96,11 +96,11 @@ cc_library_host_static {
         "link/ProductFilter.cpp",
         "link/PrivateAttributeMover.cpp",
         "link/ReferenceLinker.cpp",
-        "link/ResourceDeduper.cpp",
         "link/TableMerger.cpp",
-        "link/VersionCollapser.cpp",
         "link/XmlNamespaceRemover.cpp",
         "link/XmlReferenceLinker.cpp",
+        "optimize/ResourceDeduper.cpp",
+        "optimize/VersionCollapser.cpp",
         "process/SymbolTable.cpp",
         "proto/ProtoHelpers.cpp",
         "proto/TableProtoDeserializer.cpp",

tools/aapt2/LoadedApk.cpp

@@ -58,7 +58,8 @@ std::unique_ptr<LoadedApk> LoadedApk::LoadApkFromPath(IAaptContext* context,
   return util::make_unique<LoadedApk>(source, std::move(apk), std::move(table));
 }
 
-bool LoadedApk::WriteToArchive(IAaptContext* context, IArchiveWriter* writer) {
+bool LoadedApk::WriteToArchive(IAaptContext* context, const TableFlattenerOptions& options,
+                               IArchiveWriter* writer) {
   std::set<std::string> referenced_resources;
   // List the files being referenced in the resource table.
   for (auto& pkg : table_->packages) {
@@ -96,7 +97,7 @@ bool LoadedApk::WriteToArchive(IAaptContext* context, IArchiveWriter* writer) {
       BigBuffer buffer = BigBuffer(1024);
       // TODO(adamlesinski): How to determine if there were sparse entries (and if to encode
       // with sparse entries) b/35389232.
-      TableFlattener flattener({}, &buffer);
+      TableFlattener flattener(options, &buffer);
       if (!flattener.Consume(context, table_.get())) {
         return false;
       }

tools/aapt2/LoadedApk.h

@@ -21,6 +21,7 @@
 
 #include "ResourceTable.h"
 #include "flatten/Archive.h"
+#include "flatten/TableFlattener.h"
 #include "io/ZipArchive.h"
 #include "unflatten/BinaryResourceParser.h"
 
@@ -45,7 +46,8 @@ class LoadedApk {
    * Writes the APK on disk at the given path, while also removing the resource
    * files that are not referenced in the resource table.
    */
-  bool WriteToArchive(IAaptContext* context, IArchiveWriter* writer);
+  bool WriteToArchive(IAaptContext* context, const TableFlattenerOptions& options,
+                      IArchiveWriter* writer);
 
   static std::unique_ptr<LoadedApk> LoadApkFromPath(IAaptContext* context,
                                                     const android::StringPiece& path);

tools/aapt2/Main.cpp

@@ -25,7 +25,7 @@ namespace aapt {
 static const char* sMajorVersion = "2";
 
 // Update minor version whenever a feature or flag is added.
-static const char* sMinorVersion = "8";
+static const char* sMinorVersion = "9";
 
 int PrintVersion() {
   std::cerr << "Android Asset Packaging Tool (aapt) " << sMajorVersion << "."
@@ -37,7 +37,7 @@ extern int Compile(const std::vector<android::StringPiece>& args);
 extern int Link(const std::vector<android::StringPiece>& args);
 extern int Dump(const std::vector<android::StringPiece>& args);
 extern int Diff(const std::vector<android::StringPiece>& args);
-extern int Strip(const std::vector<android::StringPiece>& args);
+extern int Optimize(const std::vector<android::StringPiece>& args);
 
 }  // namespace aapt
 
@@ -60,8 +60,8 @@ int main(int argc, char** argv) {
       return aapt::Dump(args);
     } else if (command == "diff") {
       return aapt::Diff(args);
-    } else if (command == "strip") {
-      return aapt::Strip(args);
+    } else if (command == "optimize") {
+      return aapt::Optimize(args);
     } else if (command == "version") {
       return aapt::PrintVersion();
     }
@@ -70,7 +70,7 @@ int main(int argc, char** argv) {
     std::cerr << "no command specified\n";
   }
 
-  std::cerr << "\nusage: aapt2 [compile|link|dump|diff|strip|version] ..."
+  std::cerr << "\nusage: aapt2 [compile|link|dump|diff|optimize|version] ..."
             << std::endl;
   return 1;
 }

tools/aapt2/link/Link.cpp

@@ -46,6 +46,8 @@
 #include "link/ManifestFixer.h"
 #include "link/ReferenceLinker.h"
 #include "link/TableMerger.h"
+#include "optimize/ResourceDeduper.h"
+#include "optimize/VersionCollapser.h"
 #include "process/IResourceTableConsumer.h"
 #include "process/SymbolTable.h"
 #include "proto/ProtoSerialize.h"

tools/aapt2/link/Linkers.h

@@ -58,29 +58,6 @@ class AutoVersioner : public IResourceTableConsumer {
   DISALLOW_COPY_AND_ASSIGN(AutoVersioner);
 };
 
-class VersionCollapser : public IResourceTableConsumer {
- public:
-  VersionCollapser() = default;
-
-  bool Consume(IAaptContext* context, ResourceTable* table) override;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(VersionCollapser);
-};
-
-/**
- * Removes duplicated key-value entries from dominated resources.
- */
-class ResourceDeduper : public IResourceTableConsumer {
- public:
-  ResourceDeduper() = default;
-
-  bool Consume(IAaptContext* context, ResourceTable* table) override;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(ResourceDeduper);
-};
-
 /**
  * If any attribute resource values are defined as public, this consumer will
  * move all private

tools/aapt2/optimize/Optimize.cpp

@@ -22,21 +22,27 @@
 #include "Diagnostics.h"
 #include "Flags.h"
 #include "LoadedApk.h"
+#include "SdkConstants.h"
+#include "flatten/TableFlattener.h"
+#include "optimize/ResourceDeduper.h"
+#include "optimize/VersionCollapser.h"
 #include "split/TableSplitter.h"
 
 using android::StringPiece;
 
 namespace aapt {
 
-struct StripOptions {
-  /** Path to the output APK. */
+struct OptimizeOptions {
+  // Path to the output APK.
   std::string output_path;
 
-  /** List of screen density configurations the APK will be optimized for. */
+  // List of screen density configurations the APK will be optimized for.
   std::vector<ConfigDescription> target_configs;
+
+  TableFlattenerOptions table_flattener_options;
 };
 
-class StripContext : public IAaptContext {
+class OptimizeContext : public IAaptContext {
  public:
   IDiagnostics* GetDiagnostics() override { return &diagnostics_; }
 
@@ -61,22 +67,36 @@ class StripContext : public IAaptContext {
 
   void SetVerbose(bool val) { verbose_ = val; }
 
-  int GetMinSdkVersion() override { return 0; }
+  void SetMinSdkVersion(int sdk_version) { sdk_version_ = sdk_version; }
+
+  int GetMinSdkVersion() override { return sdk_version_; }
 
  private:
   StdErrDiagnostics diagnostics_;
   bool verbose_ = false;
+  int sdk_version_ = 0;
 };
 
-class StripCommand {
+class OptimizeCommand {
  public:
-  StripCommand(StripContext* context, const StripOptions& options)
+  OptimizeCommand(OptimizeContext* context, const OptimizeOptions& options)
       : options_(options),
         context_(context) {}
 
   int Run(std::unique_ptr<LoadedApk> apk) {
     if (context_->IsVerbose()) {
-      context_->GetDiagnostics()->Note(DiagMessage() << "Stripping APK...");
+      context_->GetDiagnostics()->Note(DiagMessage() << "Optimizing APK...");
+    }
+
+    VersionCollapser collapser;
+    if (!collapser.Consume(context_, apk->GetResourceTable())) {
+      return 1;
+    }
+
+    ResourceDeduper deduper;
+    if (!deduper.Consume(context_, apk->GetResourceTable())) {
+      context_->GetDiagnostics()->Error(DiagMessage() << "failed deduping resources");
+      return 1;
     }
 
     // Stripping the APK using the TableSplitter with no splits and the target
@@ -92,7 +112,7 @@ class StripCommand {
 
     std::unique_ptr<IArchiveWriter> writer =
         CreateZipFileArchiveWriter(context_->GetDiagnostics(), options_.output_path);
-    if (!apk->WriteToArchive(context_, writer.get())) {
+    if (!apk->WriteToArchive(context_, options_.table_flattener_options, writer.get())) {
       return 1;
     }
 
@@ -100,33 +120,37 @@ class StripCommand {
   }
 
  private:
-  StripOptions options_;
-  StripContext* context_;
+  OptimizeOptions options_;
+  OptimizeContext* context_;
 };
 
-int Strip(const std::vector<StringPiece>& args) {
-  StripContext context;
-  StripOptions options;
-  std::string target_densities;
+int Optimize(const std::vector<StringPiece>& args) {
+  OptimizeContext context;
+  OptimizeOptions options;
+  Maybe<std::string> target_densities;
   bool verbose = false;
   Flags flags =
       Flags()
           .RequiredFlag("-o", "Path to the output APK.", &options.output_path)
-          .RequiredFlag(
+          .OptionalFlag(
               "--target-densities",
               "Comma separated list of the screen densities that the APK will "
               "be optimized for. All the resources that would be unused on "
               "devices of the given densities will be removed from the APK.",
               &target_densities)
+          .OptionalSwitch("--enable-sparse-encoding",
+                          "Enables encoding sparse entries using a binary search tree.\n"
+                          "This decreases APK size at the cost of resource retrieval performance.",
+                          &options.table_flattener_options.use_sparse_entries)
           .OptionalSwitch("-v", "Enables verbose logging", &verbose);
 
-  if (!flags.Parse("aapt2 strip", args, &std::cerr)) {
+  if (!flags.Parse("aapt2 optimize", args, &std::cerr)) {
     return 1;
   }
 
   if (flags.GetArgs().size() != 1u) {
     std::cerr << "must have one APK as argument.\n\n";
-    flags.Usage("aapt2 strip", &std::cerr);
+    flags.Usage("aapt2 optimize", &std::cerr);
     return 1;
   }
 
@@ -140,32 +164,37 @@ int Strip(const std::vector<StringPiece>& args) {
     context.SetVerbose(verbose);
   }
 
-  // Parse the target screen densities.
-  for (const StringPiece& config_str : util::Tokenize(target_densities, ',')) {
-    ConfigDescription config;
-    if (!ConfigDescription::Parse(config_str, &config) || config.density == 0) {
-      context.GetDiagnostics()->Error(
-          DiagMessage() << "invalid density '" << config_str
-                        << "' for --target-densities option");
-      return 1;
+  if (target_densities) {
+    // Parse the target screen densities.
+    for (const StringPiece& config_str : util::Tokenize(target_densities.value(), ',')) {
+      ConfigDescription config;
+      if (!ConfigDescription::Parse(config_str, &config) || config.density == 0) {
+        context.GetDiagnostics()->Error(
+            DiagMessage() << "invalid density '" << config_str
+                          << "' for --target-densities option");
+        return 1;
+      }
+
+      // Clear the version that can be automatically added.
+      config.sdkVersion = 0;
+
+      if (config.diff(ConfigDescription::DefaultConfig()) !=
+          ConfigDescription::CONFIG_DENSITY) {
+        context.GetDiagnostics()->Error(
+            DiagMessage() << "invalid density '" << config_str
+                          << "' for --target-densities option. Must be only a "
+                          << "density value.");
+        return 1;
+      }
+
+      options.target_configs.push_back(config);
     }
-
-    // Clear the version that can be automatically added.
-    config.sdkVersion = 0;
-
-    if (config.diff(ConfigDescription::DefaultConfig()) !=
-        ConfigDescription::CONFIG_DENSITY) {
-      context.GetDiagnostics()->Error(
-          DiagMessage() << "invalid density '" << config_str
-                        << "' for --target-densities option. Must be only a "
-                        << "density value.");
-      return 1;
-    }
-
-    options.target_configs.push_back(config);
   }
 
-  StripCommand cmd(&context, options);
+  // TODO(adamlesinski): Read manfiest and set the proper minSdkVersion.
+  // context.SetMinSdkVersion(SDK_O);
+
+  OptimizeCommand cmd(&context, options);
   return cmd.Run(std::move(apk));
 }
 

tools/aapt2/optimize/ResourceDeduper.cpp

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "link/Linkers.h"
+#include "optimize/ResourceDeduper.h"
 
 #include <algorithm>
 

tools/aapt2/optimize/ResourceDeduper.h

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#ifndef AAPT_OPTIMIZE_RESOURCEDEDUPER_H
+#define AAPT_OPTIMIZE_RESOURCEDEDUPER_H
+
+#include "android-base/macros.h"
+
+#include "process/IResourceTableConsumer.h"
+
+namespace aapt {
+
+class ResourceTable;
+
+// Removes duplicated key-value entries from dominated resources.
+class ResourceDeduper : public IResourceTableConsumer {
+ public:
+  ResourceDeduper() = default;
+
+  bool Consume(IAaptContext* context, ResourceTable* table) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ResourceDeduper);
+};
+
+} // namespace aapt
+
+#endif  // AAPT_OPTIMIZE_RESOURCEDEDUPER_H

tools/aapt2/optimize/ResourceDeduper_test.cpp

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "link/Linkers.h"
+#include "optimize/ResourceDeduper.h"
 
 #include "ResourceTable.h"
 #include "test/Test.h"

tools/aapt2/optimize/VersionCollapser.cpp

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "link/Linkers.h"
+#include "optimize/VersionCollapser.h"
 
 #include <algorithm>
 #include <vector>

tools/aapt2/optimize/VersionCollapser.h

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#ifndef AAPT_OPTIMIZE_VERSIONCOLLAPSER_H
+#define AAPT_OPTIMIZE_VERSIONCOLLAPSER_H
+
+#include "android-base/macros.h"
+
+#include "process/IResourceTableConsumer.h"
+
+namespace aapt {
+
+class ResourceTable;
+
+class VersionCollapser : public IResourceTableConsumer {
+ public:
+  VersionCollapser() = default;
+
+  bool Consume(IAaptContext* context, ResourceTable* table) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(VersionCollapser);
+};
+
+} // namespace aapt
+
+#endif  // AAPT_OPTIMIZE_VERSIONCOLLAPSER_H

tools/aapt2/optimize/VersionCollapser_test.cpp

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "link/Linkers.h"
+#include "optimize/VersionCollapser.h"
 
 #include "test/Test.h"
 

tools/aapt2/readme.md

@@ -1,5 +1,20 @@
 # Android Asset Packaging Tool 2.0 (AAPT2) release notes
 
+## Version 2.9
+### `aapt2 link ...`
+- Added sparse resource type encoding, which encodes resource entries that are sparse with
+  a binary search tree representation. Only available when minSdkVersion >= API O or resource
+  qualifier of resource types is >= v26 (or whatever API level O becomes). Enabled with
+  `--enable-sparse-encoding` flag.
+### `aapt2 optimize ...`
+- Adds an optimization pass that supports:
+    - stripping out any density assets that do not match the `--target-densities` list of
+      densities.
+    - resource deduping when the resources are dominated and identical (already happens during
+      `link` phase but this covers apps built with `aapt`).
+    - new sparse resource type encoding with the `--enable-sparse-encoding` flag if possible
+      (minSdkVersion >= O or resource qualifier >= v26).
+
 ## Version 2.8
 ### `aapt2 link ...`
 - Adds shared library support. Build a shared library with the `--shared-lib` flag.