Implement iOS app install deltas (#77756)

packages/flutter_tools/lib/src/application_package.dart

@@ -414,6 +414,10 @@ abstract class IOSApp extends ApplicationPackage {
   String get simulatorBundlePath;
 
   String get deviceBundlePath;
+
+  /// Directory used by ios-deploy to store incremental installation metadata for
+  /// faster second installs.
+  Directory get appDeltaDirectory;
 }
 
 class BuildableIOSApp extends IOSApp {
@@ -440,6 +444,9 @@ class BuildableIOSApp extends IOSApp {
   @override
   String get deviceBundlePath => _buildAppPath('iphoneos');
 
+  @override
+  Directory get appDeltaDirectory => globals.fs.directory(globals.fs.path.join(getIosBuildDirectory(), 'app-delta'));
+
   // Xcode uses this path for the final archive bundle location,
   // not a top-level output directory.
   // Specifying `build/ios/archive/Runner` will result in `build/ios/archive/Runner.xcarchive`.
@@ -468,6 +475,9 @@ class PrebuiltIOSApp extends IOSApp {
   final Directory bundleDir;
   final String bundleName;
 
+  @override
+  final Directory appDeltaDirectory = null;
+
   @override
   String get name => bundleName;
 

packages/flutter_tools/lib/src/ios/devices.dart

@@ -258,6 +258,7 @@ class IOSDevice extends Device {
       installationResult = await _iosDeploy.installApp(
         deviceId: id,
         bundlePath: bundle.path,
+        appDeltaDirectory: app.appDeltaDirectory,
         launchArguments: <String>[],
         interfaceType: interfaceType,
       );
@@ -384,6 +385,7 @@ class IOSDevice extends Device {
           iosDeployDebugger = _iosDeploy.prepareDebuggerForLaunch(
             deviceId: id,
             bundlePath: bundle.path,
+            appDeltaDirectory: package.appDeltaDirectory,
             launchArguments: launchArguments,
             interfaceType: interfaceType,
           );
@@ -404,6 +406,7 @@ class IOSDevice extends Device {
         installationResult = await _iosDeploy.launchApp(
           deviceId: id,
           bundlePath: bundle.path,
+          appDeltaDirectory: package.appDeltaDirectory,
           launchArguments: launchArguments,
           interfaceType: interfaceType,
         );

packages/flutter_tools/lib/src/ios/ios_deploy.dart

@@ -11,6 +11,7 @@ import 'package:process/process.dart';
 
 import '../artifacts.dart';
 import '../base/common.dart';
+import '../base/file_system.dart';
 import '../base/io.dart';
 import '../base/logger.dart';
 import '../base/platform.dart';
@@ -89,15 +90,21 @@ class IOSDeploy {
   Future<int> installApp({
     @required String deviceId,
     @required String bundlePath,
+    @required Directory appDeltaDirectory,
     @required List<String>launchArguments,
     @required IOSDeviceInterface interfaceType,
   }) async {
+    appDeltaDirectory?.createSync(recursive: true);
     final List<String> launchCommand = <String>[
       _binaryPath,
       '--id',
       deviceId,
       '--bundle',
       bundlePath,
+      if (appDeltaDirectory != null) ...<String>[
+        '--app_deltas',
+        appDeltaDirectory.path,
+      ],
       if (interfaceType != IOSDeviceInterface.network)
         '--no-wifi',
       if (launchArguments.isNotEmpty) ...<String>[
@@ -121,9 +128,11 @@ class IOSDeploy {
   IOSDeployDebugger prepareDebuggerForLaunch({
     @required String deviceId,
     @required String bundlePath,
+    @required Directory appDeltaDirectory,
     @required List<String> launchArguments,
     @required IOSDeviceInterface interfaceType,
   }) {
+    appDeltaDirectory?.createSync(recursive: true);
     // Interactive debug session to support sending the lldb detach command.
     final List<String> launchCommand = <String>[
       'script',
@@ -135,6 +144,10 @@ class IOSDeploy {
       deviceId,
       '--bundle',
       bundlePath,
+      if (appDeltaDirectory != null) ...<String>[
+        '--app_deltas',
+        appDeltaDirectory.path,
+      ],
       '--debug',
       if (interfaceType != IOSDeviceInterface.network)
         '--no-wifi',
@@ -157,15 +170,21 @@ class IOSDeploy {
   Future<int> launchApp({
     @required String deviceId,
     @required String bundlePath,
+    @required Directory appDeltaDirectory,
     @required List<String> launchArguments,
     @required IOSDeviceInterface interfaceType,
   }) async {
+    appDeltaDirectory?.createSync(recursive: true);
     final List<String> launchCommand = <String>[
       _binaryPath,
       '--id',
       deviceId,
       '--bundle',
       bundlePath,
+      if (appDeltaDirectory != null) ...<String>[
+        '--app_deltas',
+        appDeltaDirectory.path,
+      ],
       if (interfaceType != IOSDeviceInterface.network)
         '--no-wifi',
       '--justlaunch',

packages/flutter_tools/lib/src/ios/mac.dart

@@ -426,18 +426,24 @@ Future<XcodeBuildResult> buildXcodeProject({
         targetBuildDir,
         buildSettings['WRAPPER_NAME'],
       );
-      if (globals.fs.isDirectorySync(expectedOutputDirectory)) {
+      if (globals.fs.directory(expectedOutputDirectory).existsSync()) {
         // Copy app folder to a place where other tools can find it without knowing
         // the BuildInfo.
-        outputDir = expectedOutputDirectory.replaceFirst('/$configuration-', '/');
-        if (globals.fs.isDirectorySync(outputDir)) {
-          // Previous output directory might have incompatible artifacts
-          // (for example, kernel binary files produced from previous run).
-          globals.fs.directory(outputDir).deleteSync(recursive: true);
-        }
-        copyDirectory(
-          globals.fs.directory(expectedOutputDirectory),
-          globals.fs.directory(outputDir),
+        outputDir = targetBuildDir.replaceFirst('/$configuration-', '/');
+        globals.fs.directory(outputDir).createSync(recursive: true);
+
+        // rsync instead of copy to maintain timestamps to support incremental
+        // app install deltas. Use --delete to remove incompatible artifacts
+        // (for example, kernel binary files produced from previous run).
+        await globals.processUtils.run(
+          <String>[
+            'rsync',
+            '-av',
+            '--delete',
+            expectedOutputDirectory,
+            outputDir,
+          ],
+          throwOnError: true,
         );
       } else {
         globals.printError('Build succeeded but the expected app at $expectedOutputDirectory not found');

packages/flutter_tools/test/general.shard/ios/ios_deploy_test.dart

@@ -7,6 +7,8 @@
 import 'dart:async';
 import 'dart:convert';
 
+import 'package:file/memory.dart';
+import 'package:file_testing/file_testing.dart';
 import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/logger.dart';
@@ -23,10 +25,12 @@ import '../../src/fakes.dart';
 void main () {
   Artifacts artifacts;
   String iosDeployPath;
+  FileSystem fileSystem;
 
   setUp(() {
     artifacts = Artifacts.test();
     iosDeployPath = artifacts.getArtifactPath(Artifact.iosDeploy, platform: TargetPlatform.ios);
+    fileSystem = MemoryFileSystem.test();
   });
 
   testWithoutContext('IOSDeploy.iosDeployEnv returns path with /usr/bin first', () {
@@ -50,6 +54,8 @@ void main () {
             '123',
             '--bundle',
             '/',
+            '--app_deltas',
+            'app-delta',
             '--debug',
             '--args',
             <String>[
@@ -62,10 +68,12 @@ void main () {
           stdout: '(lldb)     run\nsuccess\nDid finish launching.',
         ),
       ]);
+      final Directory appDeltaDirectory = fileSystem.directory('app-delta');
       final IOSDeploy iosDeploy = setUpIOSDeploy(processManager, artifacts: artifacts);
       final IOSDeployDebugger iosDeployDebugger = iosDeploy.prepareDebuggerForLaunch(
         deviceId: '123',
         bundlePath: '/',
+        appDeltaDirectory: appDeltaDirectory,
         launchArguments: <String>['--enable-dart-profiling'],
         interfaceType: IOSDeviceInterface.network,
       );
@@ -73,6 +81,7 @@ void main () {
       expect(await iosDeployDebugger.launchAndAttach(), isTrue);
       expect(await iosDeployDebugger.logLines.toList(), <String>['Did finish launching.']);
       expect(processManager.hasRemainingExpectations, false);
+      expect(appDeltaDirectory, exists);
     });
   });
 

packages/flutter_tools/test/general.shard/ios/ios_device_start_nonprebuilt_test.dart

@@ -5,6 +5,7 @@
 // @dart = 2.8
 
 import 'package:file/memory.dart';
+import 'package:file_testing/file_testing.dart';
 import 'package:flutter_tools/src/application_package.dart';
 import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
@@ -119,10 +120,22 @@ void main() {
       setUpIOSProject(fileSystem);
       final FlutterProject flutterProject = FlutterProject.fromDirectory(fileSystem.currentDirectory);
       final BuildableIOSApp buildableIOSApp = BuildableIOSApp(flutterProject.ios, 'flutter', 'My Super Awesome App.app');
+      fileSystem.directory('build/ios/Release-iphoneos/My Super Awesome App.app').createSync(recursive: true);
 
       processManager.addCommand(FakeCommand(command: _xattrArgs(flutterProject)));
       processManager.addCommand(const FakeCommand(command: kRunReleaseArgs));
-      processManager.addCommand(const FakeCommand(command: <String>[...kRunReleaseArgs, '-showBuildSettings']));
+      processManager.addCommand(const FakeCommand(command: <String>[...kRunReleaseArgs, '-showBuildSettings'], stdout: r'''
+      TARGET_BUILD_DIR=build/ios/Release-iphoneos
+      WRAPPER_NAME=My Super Awesome App.app
+      '''
+      ));
+      processManager.addCommand(const FakeCommand(command: <String>[
+        'rsync',
+        '-av',
+        '--delete',
+        'build/ios/Release-iphoneos/My Super Awesome App.app',
+        'build/ios/iphoneos',
+      ]));
       processManager.addCommand(FakeCommand(
         command: <String>[
           iosDeployPath,
@@ -130,6 +143,8 @@ void main() {
           '123',
           '--bundle',
           'build/ios/iphoneos/My Super Awesome App.app',
+          '--app_deltas',
+          'build/ios/app-delta',
           '--no-wifi',
           '--justlaunch',
           '--args',
@@ -146,6 +161,7 @@ void main() {
         platformArgs: <String, Object>{},
       );
 
+      expect(fileSystem.directory('build/ios/iphoneos'), exists);
       expect(launchResult.started, true);
       expect(processManager.hasRemainingExpectations, false);
     }, overrides: <Type, Generator>{
@@ -169,6 +185,7 @@ void main() {
         setUpIOSProject(fileSystem);
         final FlutterProject flutterProject = FlutterProject.fromDirectory(fileSystem.currentDirectory);
         final BuildableIOSApp buildableIOSApp = BuildableIOSApp(flutterProject.ios, 'flutter', 'My Super Awesome App.app');
+        fileSystem.directory('build/ios/Release-iphoneos/My Super Awesome App.app').createSync(recursive: true);
 
         processManager.addCommand(FakeCommand(command: _xattrArgs(flutterProject)));
         processManager.addCommand(const FakeCommand(command: kRunReleaseArgs));
@@ -183,7 +200,18 @@ void main() {
           const FakeCommand(
             command: <String>[...kRunReleaseArgs, '-showBuildSettings'],
             exitCode: 0,
+            stdout: r'''
+      TARGET_BUILD_DIR=build/ios/Release-iphoneos
+      WRAPPER_NAME=My Super Awesome App.app
+      '''
           ));
+        processManager.addCommand(const FakeCommand(command: <String>[
+          'rsync',
+          '-av',
+          '--delete',
+          'build/ios/Release-iphoneos/My Super Awesome App.app',
+          'build/ios/iphoneos',
+        ]));
         processManager.addCommand(FakeCommand(
           command: <String>[
             iosDeployPath,
@@ -191,6 +219,8 @@ void main() {
             '123',
             '--bundle',
             'build/ios/iphoneos/My Super Awesome App.app',
+            '--app_deltas',
+            'build/ios/app-delta',
             '--no-wifi',
             '--justlaunch',
             '--args',
@@ -221,6 +251,7 @@ void main() {
       });
 
       expect(launchResult?.started, true);
+      expect(fileSystem.directory('build/ios/iphoneos'), exists);
       expect(processManager.hasRemainingExpectations, false);
     }, overrides: <Type, Generator>{
       ProcessManager: () => processManager,