Revert "Reland "Default the CanvasKit base URL to local artifacts. (#40293)" (#40470)" (flutter/engine#40700)

Revert "Reland "Default the CanvasKit base URL to local artifacts.""

engine/src/flutter/lib/web_ui/README.md

@@ -214,6 +214,34 @@ Resources:
 2. LUCI web [recipe][5]
 3. More general reading on CIPD packages [link][6]
 
+### Rolling CanvasKit
+
+CanvasKit is versioned separately from Skia and rolled manually. Flutter
+consumes a pre-built CanvasKit provided by the Skia team, currently hosted on
+unpkg.com. When a new version of CanvasKit is available (check
+https://www.npmjs.com/package/canvaskit-wasm or consult the Skia team
+directly), follow these steps to roll to the new version:
+
+- Make sure you have `depot_tools` installed (if you are regularly hacking on
+  the engine code, you probably do).
+- If not already authenticated with CIPD, run `cipd auth-login` and follow
+  instructions (this step requires sufficient privileges; file a github
+  infra ticket queue issue: https://github.com/flutter/flutter/wiki/Infra-Ticket-Queue
+  to get access)
+- Edit `dev/canvaskit_lock.yaml` and update the value of `canvaskit_version`
+  to the new version.
+- Run `dart dev/canvaskit_roller.dart` and make sure it completes successfully.
+  The script uploads the new version of CanvasKit to the
+  `flutter/web/canvaskit_bundle` CIPD package, and writes the CIPD package
+  instance ID to the DEPS file.
+- Rerun `gclient sync` and do a clean build to test that the new version is
+  picked up.
+- Send a pull request containing the above file changes. If the new version
+  contains breaking changes, the PR must also contain corresponding fixes.
+
+If you have questions, contact the Flutter Web team on Flutter Discord on the
+#hackers-web-🌍 channel.
+
 ### Rolling Noto Font Data
 
 In order to generate new data for the Noto fallback fonts, you will need

engine/src/flutter/lib/web_ui/dev/canvaskit_lock.yaml

@@ -0,0 +1,4 @@
+# Specifies the version of CanvasKit to use for Flutter Web apps.
+#
+# See `lib/web_ui/README.md` for how to update this file.
+canvaskit_version: "0.38.0"

engine/src/flutter/lib/web_ui/dev/canvaskit_roller.dart

@@ -0,0 +1,169 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:convert' show json;
+import 'dart:io';
+
+import 'package:path/path.dart' as pathlib;
+import 'package:yaml/yaml.dart';
+
+import 'environment.dart';
+import 'utils.dart';
+
+/// Rolls CanvasKit to the version specified in `dev/canvaskit_lock.yaml`.
+///
+/// Detailed instructions for how to use this script can be found in
+/// `lib/web_ui/README.md`.
+Future<void> main(List<String> args) async {
+  final String canvaskitVersion = _readCanvaskitVersion();
+  print('Rolling CanvasKit to version $canvaskitVersion');
+
+  final Directory canvaskitDirectory = await Directory.systemTemp.createTemp('canvaskit-roll-$canvaskitVersion-');
+  print('Will use ${canvaskitDirectory.path} as staging directory.');
+
+  final String baseUrl = 'https://unpkg.com/canvaskit-wasm@$canvaskitVersion/bin/';
+  print('Downloading CanvasKit from $baseUrl');
+  final HttpClient client = HttpClient();
+  for (final String assetPath in _canvaskitAssets) {
+    final String assetUrl = '$baseUrl/$assetPath';
+    final File assetFile = File(pathlib.joinAll(<String>[
+      canvaskitDirectory.path,
+      'canvaskit',
+      ...assetPath.split('/'), // so it's compatible with Windows
+    ]));
+    await assetFile.parent.create(recursive: true);
+    final HttpClientRequest request = await client.getUrl(Uri.parse(assetUrl));
+    final HttpClientResponse response = await request.close();
+    final IOSink fileSink = assetFile.openWrite();
+    await response.pipe(fileSink);
+  }
+  client.close();
+
+  final File cipdConfigFile = File(pathlib.join(
+    canvaskitDirectory.path,
+    'cipd.yaml',
+  ));
+  await cipdConfigFile.writeAsString('''
+package: flutter/web/canvaskit_bundle
+description: A build of CanvasKit bundled with Flutter Web apps
+preserve_writable: true
+data:
+  - dir: canvaskit
+''');
+
+  print('Uploading to CIPD');
+  await runProcess('cipd', <String>[
+    'create',
+    '--tag=version:$canvaskitVersion',
+    '--pkg-def=cipd.yaml',
+    '--json-output=result.json',
+  ], workingDirectory: canvaskitDirectory.path);
+
+  final Map<String, dynamic> cipdResult = json.decode(File(pathlib.join(
+    canvaskitDirectory.path,
+    'result.json',
+  )).readAsStringSync()) as Map<String, dynamic>;
+  final String cipdInstanceId = (cipdResult['result'] as Map<dynamic, dynamic>)['instance_id'] as String;
+
+  print('CIPD instance information:');
+  final String cipdInfo = await evalProcess('cipd', <String>[
+    'describe',
+    'flutter/web/canvaskit_bundle',
+    '--version=$cipdInstanceId',
+  ], workingDirectory: canvaskitDirectory.path);
+  print(cipdInfo.trim().split('\n').map((String line) => ' • $line').join('\n'));
+
+  print('Updating DEPS file');
+  await _updateDepsFile(cipdInstanceId);
+  await _updateCanvaskitInitializationCode(canvaskitVersion);
+
+  print('\nATTENTION: the roll process is not complete yet.');
+  print('Last step: for the roll to take effect submit an engine pull request from local git changes.');
+}
+
+const List<String> _canvaskitAssets = <String>[
+  'canvaskit.js',
+  'canvaskit.wasm',
+  'profiling/canvaskit.js',
+  'profiling/canvaskit.wasm',
+];
+
+String _readCanvaskitVersion() {
+  final YamlMap canvaskitLock = loadYaml(File(pathlib.join(
+    environment.webUiDevDir.path,
+    'canvaskit_lock.yaml',
+  )).readAsStringSync()) as YamlMap;
+  return canvaskitLock['canvaskit_version'] as String;
+}
+
+Future<void> _updateDepsFile(String cipdInstanceId) async {
+  final File depsFile = File(pathlib.join(
+    environment.flutterDirectory.path,
+    'DEPS',
+  ));
+
+  final String originalDepsCode = await depsFile.readAsString();
+  final List<String> rewrittenDepsCode = <String>[];
+  const String kCanvasKitDependencyKeyInDeps = "'canvaskit_cipd_instance': '";
+  bool canvaskitDependencyFound = false;
+  for (final String line in originalDepsCode.split('\n')) {
+    if (line.trim().startsWith(kCanvasKitDependencyKeyInDeps)) {
+      canvaskitDependencyFound = true;
+      rewrittenDepsCode.add(
+        "  'canvaskit_cipd_instance': '$cipdInstanceId',",
+      );
+    } else {
+      rewrittenDepsCode.add(line);
+    }
+  }
+
+  if (!canvaskitDependencyFound) {
+    stderr.writeln(
+      'Failed to update the DEPS file.\n'
+      'Could not to locate CanvasKit dependency in the DEPS file. Make sure the '
+      'DEPS file contains a line like this:\n'
+      '\n'
+      "  'canvaskit_cipd_instance': 'SOME_VALUE',"
+    );
+    exit(1);
+  }
+
+  await depsFile.writeAsString(rewrittenDepsCode.join('\n'));
+}
+
+Future<void> _updateCanvaskitInitializationCode(String canvaskitVersion) async {
+  const String kCanvasKitVersionKey = 'const String _canvaskitVersion';
+  const String kPathToConfigurationCode = 'lib/src/engine/configuration.dart';
+  final File initializationFile = File(pathlib.join(
+    environment.webUiRootDir.path,
+    kPathToConfigurationCode,
+  ));
+  final String originalInitializationCode = await initializationFile.readAsString();
+
+  final List<String> rewrittenCode = <String>[];
+  bool canvaskitVersionFound = false;
+  for (final String line in originalInitializationCode.split('\n')) {
+    if (line.trim().startsWith(kCanvasKitVersionKey)) {
+      canvaskitVersionFound = true;
+      rewrittenCode.add(
+        "const String _canvaskitVersion = '$canvaskitVersion';",
+      );
+    } else {
+      rewrittenCode.add(line);
+    }
+  }
+
+  if (!canvaskitVersionFound) {
+    stderr.writeln(
+      'Failed to update CanvasKit version in $kPathToConfigurationCode.\n'
+      'Could not to locate the constant that defines the version. Make sure the '
+      '$kPathToConfigurationCode file contains a line like this:\n'
+      '\n'
+      "const String _canvaskitVersion = 'VERSION';"
+    );
+    exit(1);
+  }
+
+  await initializationFile.writeAsString(rewrittenCode.join('\n'));
+}

engine/src/flutter/lib/web_ui/lib/src/engine/configuration.dart

@@ -50,6 +50,11 @@ import 'package:meta/meta.dart';
 import 'canvaskit/renderer.dart';
 import 'dom.dart';
 
+/// The version of CanvasKit used by the web engine by default.
+// DO NOT EDIT THE NEXT LINE OF CODE MANUALLY
+// See `lib/web_ui/README.md` for how to roll CanvasKit to a new version.
+const String _canvaskitVersion = '0.38.0';
+
 /// The Web Engine configuration for the current application.
 FlutterConfiguration get configuration =>
   _configuration ??= FlutterConfiguration.legacy(_jsConfiguration);
@@ -178,7 +183,7 @@ class FlutterConfiguration {
   String get canvasKitBaseUrl => _configuration?.canvasKitBaseUrl ?? _defaultCanvasKitBaseUrl;
   static const String _defaultCanvasKitBaseUrl = String.fromEnvironment(
     'FLUTTER_WEB_CANVASKIT_URL',
-    defaultValue: 'canvaskit/',
+    defaultValue: 'https://unpkg.com/canvaskit-wasm@$_canvaskitVersion/bin/',
   );
 
   /// The variant of CanvasKit to download.