[flutter_tools] Deferred components build system

dev/bots/test.dart

@@ -519,7 +519,7 @@ Future<void> _flutterBuild(
     final File file = File(path.join(flutterRoot, relativePathToApplication, 'perf.json'));
     if (!_allTargetsCached(file)) {
       print('${red}Not all build targets cached after second run.$reset');
-      print('The target performance data was: ${file.readAsStringSync()}');
+      print('The target performance data was: ${file.readAsStringSync().replaceAll('},', '},\n')}');
       exit(1);
     }
   }

packages/flutter_tools/gradle/flutter.gradle

@@ -134,6 +134,14 @@ class FlutterPlugin implements Plugin<Project> {
                 }
             }
         }
+
+        if (project.hasProperty('deferred-component-names')) {
+            String[] componentNames = project.property('deferred-component-names').split(',').collect {":${it}"}
+            project.android {
+                dynamicFeatures = componentNames
+            }
+        }
+
         getTargetPlatforms().each { targetArch ->
             String abiValue = PLATFORM_ARCH_MAP[targetArch]
             project.android {
@@ -173,17 +181,23 @@ class FlutterPlugin implements Plugin<Project> {
                     matchingFallbacks = ["debug", "release"]
                 }
             }
-            release {
-                // Enables code shrinking, obfuscation, and optimization for only
-                // your project's release build type.
-                minifyEnabled true
-                // Enables resource shrinking, which is performed by the
-                // Android Gradle plugin.
-                // NOTE: The resource shrinker can't be used for libraries.
-                shrinkResources isBuiltAsApp(project)
-                // Fallback to `android/app/proguard-rules.pro`.
-                // This way, custom Proguard rules can be configured as needed.
-                proguardFiles project.android.getDefaultProguardFile("proguard-android.txt"), flutterProguardRules, "proguard-rules.pro"
+            // TODO(garyq): Shrinking is only false for multi apk split aot builds, where shrinking is not allowed yet.
+            // This limitation has been removed experimentally in gradle plugin version 4.2, so we can remove
+            // this check when we upgrade to 4.2+ gradle. Currently, deferred components apps may see
+            // increased app size due to this.
+            if (shouldShrinkResources(project)) {
+                release {
+                    // Enables code shrinking, obfuscation, and optimization for only
+                    // your project's release build type.
+                    minifyEnabled true
+                    // Enables resource shrinking, which is performed by the
+                    // Android Gradle plugin.
+                    // NOTE: The resource shrinker can't be used for libraries.
+                    shrinkResources isBuiltAsApp(project)
+                    // Fallback to `android/app/proguard-rules.pro`.
+                    // This way, custom Proguard rules can be configured as needed.
+                    proguardFiles project.android.getDefaultProguardFile("proguard-android.txt"), flutterProguardRules, "proguard-rules.pro"
+                }
             }
         }
 
@@ -200,6 +214,13 @@ class FlutterPlugin implements Plugin<Project> {
         project.android.buildTypes.all this.&addFlutterDependencies
     }
 
+    private static Boolean shouldShrinkResources(Project project) { 
+        if (project.hasProperty("shrink")) {
+            return project.property("shrink").toBoolean()
+        }
+        return true
+    }
+
     /**
      * Adds the dependencies required by the Flutter project.
      * This includes:
@@ -706,6 +727,14 @@ class FlutterPlugin implements Plugin<Project> {
         if (project.hasProperty('code-size-directory')) {
             codeSizeDirectoryValue = project.property('code-size-directory')
         }
+        Boolean deferredComponentsValue = false
+        if (project.hasProperty('deferred-components')) {
+            deferredComponentsValue = project.property('deferred-components').toBoolean()
+        }
+        Boolean validateDeferredComponentsValue = true
+        if (project.hasProperty('validate-deferred-components')) {
+            validateDeferredComponentsValue = project.property('validate-deferred-components').toBoolean()
+        }
         def targetPlatforms = getTargetPlatforms()
         def addFlutterDeps = { variant ->
             if (shouldSplitPerAbi()) {
@@ -747,6 +776,8 @@ class FlutterPlugin implements Plugin<Project> {
                 bundleSkSLPath bundleSkSLPathValue
                 performanceMeasurementFile performanceMeasurementFileValue
                 codeSizeDirectory codeSizeDirectoryValue
+                deferredComponents deferredComponentsValue
+                validateDeferredComponents validateDeferredComponentsValue
                 doLast {
                     project.exec {
                         if (Os.isFamily(Os.FAMILY_WINDOWS)) {
@@ -810,7 +841,8 @@ class FlutterPlugin implements Plugin<Project> {
                 processResources.dependsOn(copyFlutterAssetsTask)
             }
             return copyFlutterAssetsTask
-        }
+        } // end def addFlutterDeps
+
         if (isFlutterAppProject()) {
             project.android.applicationVariants.all { variant ->
                 Task assembleTask = getAssembleTask(variant)
@@ -883,7 +915,7 @@ class FlutterPlugin implements Plugin<Project> {
                     // | ----------------- | ----------------------------- |
                     // |   Build Variant   |   Flutter Equivalent Variant  |
                     // | ----------------- | ----------------------------- |
-                    // |   freeRelease     |   relese                      |
+                    // |   freeRelease     |   release                      |
                     // |   freeDebug       |   debug                       |
                     // |   freeDevelop     |   debug                       |
                     // |   profile         |   profile                     |
@@ -961,6 +993,10 @@ abstract class BaseFlutterTask extends DefaultTask {
     @Optional @Input
     String codeSizeDirectory;
     String performanceMeasurementFile;
+    @Optional @Input
+    Boolean deferredComponents
+    @Optional @Input
+    Boolean validateDeferredComponents
 
     @OutputFiles
     FileCollection getDependenciesFiles() {
@@ -985,6 +1021,8 @@ abstract class BaseFlutterTask extends DefaultTask {
         String[] ruleNames;
         if (buildMode == "debug") {
             ruleNames = ["debug_android_application"]
+        } else if (deferredComponents) {
+            ruleNames = targetPlatformValues.collect { "android_aot_deferred_components_bundle_${buildMode}_$it" }
         } else {
             ruleNames = targetPlatformValues.collect { "android_aot_bundle_${buildMode}_$it" }
         }

packages/flutter_tools/lib/src/android/android_builder.dart

@@ -38,5 +38,7 @@ abstract class AndroidBuilder {
     @required FlutterProject project,
     @required AndroidBuildInfo androidBuildInfo,
     @required String target,
+    bool validateDeferredComponents = true,
+    bool deferredComponentsEnabled = false,
   });
 }

packages/flutter_tools/lib/src/android/deferred_components_gen_snapshot_validator.dart

@@ -30,10 +30,17 @@ class DeferredComponentsGenSnapshotValidator extends DeferredComponentsValidator
   /// When [exitOnFail] is set to true, the [handleResults] and [attemptToolExit]
   /// methods will exit the tool when this validator detects a recommended
   /// change. This defaults to true.
-  DeferredComponentsGenSnapshotValidator(Environment env, {
+  DeferredComponentsGenSnapshotValidator(this.env, {
     bool exitOnFail = true,
     String title,
-  }) : super(env, exitOnFail: exitOnFail, title: title);
+  }) : super(env.projectDir, env.logger, exitOnFail: exitOnFail, title: title);
+
+  /// The build environment that should be used to find the input files to run
+  /// checks against.
+  ///
+  /// The checks in this class are meant to be used as part of a build process,
+  /// so an environment should be available.
+  final Environment env;
 
   // The key used to identify the metadata element as the loading unit id to
   // deferred component mapping.
@@ -58,8 +65,8 @@ class DeferredComponentsGenSnapshotValidator extends DeferredComponentsValidator
   /// Where loading unit 2 is included in componentA, loading unit 3 is included
   /// in componentB, and loading unit 4 is included in componentC.
   bool checkAppAndroidManifestComponentLoadingUnitMapping(List<DeferredComponent> components, List<LoadingUnit> generatedLoadingUnits) {
-    final Directory androidDir = env.projectDir.childDirectory('android');
-    inputs.add(env.projectDir.childFile('pubspec.yaml'));
+    final Directory androidDir = projectDir.childDirectory('android');
+    inputs.add(projectDir.childFile('pubspec.yaml'));
 
     // We do not use the Xml package to handle the writing, as we do not want to
     // erase any user applied formatting and comments. The changes can be
@@ -106,8 +113,10 @@ class DeferredComponentsGenSnapshotValidator extends DeferredComponentsValidator
       mappingBuffer.write('$key:${mapping[key]},');
     }
     String encodedMapping = mappingBuffer.toString();
-    // remove trailing comma.
-    encodedMapping = encodedMapping.substring(0, encodedMapping.length - 1);
+    // remove trailing comma if any
+    if (encodedMapping.endsWith(',')) {
+      encodedMapping = encodedMapping.substring(0, encodedMapping.length - 1);
+    }
     // Check for existing metadata entry and see if needs changes.
     bool exists = false;
     bool modified = false;
@@ -163,7 +172,7 @@ class DeferredComponentsGenSnapshotValidator extends DeferredComponentsValidator
   /// considered new.
   bool checkAgainstLoadingUnitsCache(
       List<LoadingUnit> generatedLoadingUnits) {
-    final List<LoadingUnit> cachedLoadingUnits = _parseLodingUnitsCache(env.projectDir.childFile(DeferredComponentsValidator.kLoadingUnitsCacheFileName));
+    final List<LoadingUnit> cachedLoadingUnits = _parseLodingUnitsCache(projectDir.childFile(DeferredComponentsValidator.kLoadingUnitsCacheFileName));
     loadingUnitComparisonResults = <String, dynamic>{};
     final Set<LoadingUnit> unmatchedLoadingUnits = <LoadingUnit>{};
     final List<LoadingUnit> newLoadingUnits = <LoadingUnit>[];
@@ -276,7 +285,7 @@ class DeferredComponentsGenSnapshotValidator extends DeferredComponentsValidator
   /// deferred components.
   void writeLoadingUnitsCache(List<LoadingUnit> generatedLoadingUnits) {
     generatedLoadingUnits ??= <LoadingUnit>[];
-    final File cacheFile = env.projectDir.childFile(DeferredComponentsValidator.kLoadingUnitsCacheFileName);
+    final File cacheFile = projectDir.childFile(DeferredComponentsValidator.kLoadingUnitsCacheFileName);
     outputs.add(cacheFile);
     ErrorHandlingFileSystem.deleteIfExists(cacheFile);
     cacheFile.createSync(recursive: true);

packages/flutter_tools/lib/src/android/deferred_components_prebuild_validator.dart

@@ -10,7 +10,7 @@ import 'package:xml/xml.dart';
 import '../base/deferred_component.dart';
 import '../base/error_handling_io.dart';
 import '../base/file_system.dart';
-import '../build_system/build_system.dart';
+import '../base/logger.dart';
 import '../globals.dart' as globals;
 import '../project.dart';
 import '../template.dart';
@@ -25,20 +25,18 @@ import 'deferred_components_validator.dart';
 class DeferredComponentsPrebuildValidator extends DeferredComponentsValidator {
   /// Constructs a validator instance.
   ///
-  /// The [env] property is used to locate the project files that are checked.
-  ///
   /// The [templatesDir] parameter is optional. If null, the tool's default
   /// templates directory will be used.
   ///
   /// When [exitOnFail] is set to true, the [handleResults] and [attemptToolExit]
   /// methods will exit the tool when this validator detects a recommended
   /// change. This defaults to true.
-  DeferredComponentsPrebuildValidator(Environment env, {
+  DeferredComponentsPrebuildValidator(Directory projectDir, Logger logger, {
     bool exitOnFail = true,
     String title,
     Directory templatesDir,
   }) : _templatesDir = templatesDir,
-       super(env, exitOnFail: exitOnFail, title: title);
+       super(projectDir, logger, exitOnFail: exitOnFail, title: title);
 
   final Directory _templatesDir;
 
@@ -56,15 +54,16 @@ class DeferredComponentsPrebuildValidator extends DeferredComponentsValidator {
   /// This method does not check if the contents of either of the files are
   /// valid, as there are many ways that they can be validly configured.
   Future<bool> checkAndroidDynamicFeature(List<DeferredComponent> components) async {
-    inputs.add(env.projectDir.childFile('pubspec.yaml'));
+    inputs.add(projectDir.childFile('pubspec.yaml'));
     if (components == null || components.isEmpty) {
       return false;
     }
     bool changesMade = false;
     for (final DeferredComponent component in components) {
       final _DeferredComponentAndroidFiles androidFiles = _DeferredComponentAndroidFiles(
         name: component.name,
-        env: env,
+        projectDir: projectDir,
+        logger: logger,
         templatesDir: _templatesDir
       );
       if (!androidFiles.verifyFilesExist()) {
@@ -106,8 +105,8 @@ class DeferredComponentsPrebuildValidator extends DeferredComponentsValidator {
   /// The string element's name attribute should be the component name with
   /// `Name` as a suffix, and the text contents should be the component name.
   bool checkAndroidResourcesStrings(List<DeferredComponent> components) {
-    final Directory androidDir = env.projectDir.childDirectory('android');
-    inputs.add(env.projectDir.childFile('pubspec.yaml'));
+    final Directory androidDir = projectDir.childDirectory('android');
+    inputs.add(projectDir.childFile('pubspec.yaml'));
 
     // Add component name mapping to strings.xml
     final File stringRes = androidDir
@@ -202,7 +201,7 @@ class DeferredComponentsPrebuildValidator extends DeferredComponentsValidator {
 
   /// Deletes all files inside of the validator's output directory.
   void clearOutputDir() {
-    final Directory dir = env.projectDir.childDirectory('build').childDirectory(DeferredComponentsValidator.kDeferredComponentsTempDirectory);
+    final Directory dir = projectDir.childDirectory('build').childDirectory(DeferredComponentsValidator.kDeferredComponentsTempDirectory);
     ErrorHandlingFileSystem.deleteIfExists(dir, recursive: true);
   }
 }
@@ -212,16 +211,18 @@ class DeferredComponentsPrebuildValidator extends DeferredComponentsValidator {
 class _DeferredComponentAndroidFiles {
   _DeferredComponentAndroidFiles({
     @required this.name,
-    @required this.env,
+    @required this.projectDir,
+    this.logger,
     Directory templatesDir,
   }) : _templatesDir = templatesDir;
 
   // The name of the deferred component.
   final String name;
-  final Environment env;
+  final Directory projectDir;
+  final Logger logger;
   final Directory _templatesDir;
 
-  Directory get androidDir => env.projectDir.childDirectory('android');
+  Directory get androidDir => projectDir.childDirectory('android');
   Directory get componentDir => androidDir.childDirectory(name);
 
   File get androidManifestFile => componentDir.childDirectory('src').childDirectory('main').childFile('AndroidManifest.xml');
@@ -250,18 +251,18 @@ class _DeferredComponentAndroidFiles {
   Future<List<File>> _setupComponentFiles(Directory outputDir) async {
     Template template;
     if (_templatesDir != null) {
-      final Directory templateComponentDir = _templatesDir.childDirectory('module${env.fileSystem.path.separator}android${env.fileSystem.path.separator}deferred_component');
+      final Directory templateComponentDir = _templatesDir.childDirectory('module${globals.fs.path.separator}android${globals.fs.path.separator}deferred_component');
       template = Template(templateComponentDir, templateComponentDir, _templatesDir,
-        fileSystem: env.fileSystem,
+        fileSystem: globals.fs,
         templateManifest: null,
-        logger: env.logger,
+        logger: logger,
         templateRenderer: globals.templateRenderer,
       );
     } else {
-      template = await Template.fromName('module${env.fileSystem.path.separator}android${env.fileSystem.path.separator}deferred_component',
-        fileSystem: env.fileSystem,
+      template = await Template.fromName('module${globals.fs.path.separator}android${globals.fs.path.separator}deferred_component',
+        fileSystem: globals.fs,
         templateManifest: null,
-        logger: env.logger,
+        logger: logger,
         templateRenderer: globals.templateRenderer,
       );
     }