Switch gen_snapshot from Android's one to elinux's one (#82)

lib/commands/build.dart

@@ -27,7 +27,8 @@ class ELinuxBuildCommand extends BuildCommand {
   }
 }
 
-class BuildPackageCommand extends BuildSubCommand with ELinuxExtension {
+class BuildPackageCommand extends BuildSubCommand
+    with ELinuxExtension, ELinuxRequiredArtifacts {
   /// See: [BuildApkCommand] in `build_apk.dart`
   BuildPackageCommand({bool verboseHelp = false})
       : super(verboseHelp: verboseHelp) {

lib/commands/drive.dart

@@ -8,9 +8,11 @@
 import 'package:flutter_tools/src/commands/drive.dart';
 import 'package:flutter_tools/src/globals.dart' as globals;
 
+import '../elinux_cache.dart';
 import '../elinux_plugins.dart';
 
-class ELinuxDriveCommand extends DriveCommand with ELinuxExtension {
+class ELinuxDriveCommand extends DriveCommand
+    with ELinuxExtension, ELinuxRequiredArtifacts {
   ELinuxDriveCommand({bool verboseHelp = false})
       : super(
           verboseHelp: verboseHelp,

lib/commands/run.dart

@@ -13,7 +13,8 @@ import 'package:flutter_tools/src/commands/run.dart';
 import '../elinux_cache.dart';
 import '../elinux_plugins.dart';
 
-class ELinuxRunCommand extends RunCommand with ELinuxExtension {
+class ELinuxRunCommand extends RunCommand
+    with ELinuxExtension, ELinuxRequiredArtifacts {
   ELinuxRunCommand({bool verboseHelp = false})
       : super(verboseHelp: verboseHelp);
 

lib/elinux_artifacts.dart

@@ -0,0 +1,71 @@
+// Copyright 2022 Sony Group Corporation. All rights reserved.
+// Copyright 2021 Samsung Electronics Co., Ltd. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:file/file.dart';
+import 'package:flutter_tools/src/artifacts.dart';
+import 'package:flutter_tools/src/base/os.dart';
+import 'package:flutter_tools/src/base/platform.dart';
+import 'package:flutter_tools/src/build_info.dart';
+import 'package:flutter_tools/src/cache.dart';
+
+class ELinuxArtifacts extends CachedArtifacts {
+  ELinuxArtifacts({
+    required FileSystem fileSystem,
+    required Platform platform,
+    required Cache cache,
+    required OperatingSystemUtils operatingSystemUtils,
+  })  : _cache = cache,
+        super(
+          fileSystem: fileSystem,
+          platform: platform,
+          cache: cache,
+          operatingSystemUtils: operatingSystemUtils,
+        );
+
+  final Cache _cache;
+
+  /// See: [CachedArtifacts._getEngineArtifactsPath]
+  Directory _getEngineArtifactsDirectory(String arch, BuildMode mode) {
+    return _cache
+        .getArtifactDirectory('engine')
+        .childDirectory('elinux-$arch-${mode.name}');
+  }
+
+  /// See: [CachedArtifacts._getAndroidArtifactPath] in `artifacts.dart`
+  @override
+  String getArtifactPath(
+    Artifact artifact, {
+    TargetPlatform? platform,
+    BuildMode? mode,
+    EnvironmentType? environmentType,
+  }) {
+    if (artifact == Artifact.genSnapshot &&
+        platform != null &&
+        getNameForTargetPlatform(platform).startsWith('android')) {
+      assert(mode != null, 'Need to specify a build mode.');
+      assert(mode != BuildMode.debug,
+          'Artifact $artifact only available in non-debug mode.');
+      final String arch = _getArchForTargetPlatform(platform);
+      final HostPlatform hostPlatform = getCurrentHostPlatform();
+      assert(hostPlatform != HostPlatform.linux_arm64,
+          'Artifact $artifact not available on Linux arm64.');
+      return _getEngineArtifactsDirectory(arch, mode!)
+          // TODO(hidenori): Remove this comment out.
+          // See: https://github.com/sony/flutter-elinux/issues/81
+          //.childDirectory(getNameForHostPlatform(hostPlatform))
+          .childFile('gen_snapshot')
+          .path;
+    }
+    return super.getArtifactPath(artifact, platform: platform, mode: mode);
+  }
+
+  String _getArchForTargetPlatform(TargetPlatform platform) {
+    if (platform == TargetPlatform.android_arm64) {
+      return 'arm64';
+    } else {
+      return 'x64';
+    }
+  }
+}

lib/elinux_cache.dart

@@ -12,6 +12,16 @@ import 'package:flutter_tools/src/cache.dart';
 import 'package:flutter_tools/src/features.dart';
 import 'package:flutter_tools/src/flutter_cache.dart';
 import 'package:flutter_tools/src/globals.dart' as globals;
+import 'package:flutter_tools/src/runner/flutter_command.dart';
+
+mixin ELinuxRequiredArtifacts on FlutterCommand {
+  @override
+  Future<Set<DevelopmentArtifact>> get requiredArtifacts async =>
+      <DevelopmentArtifact>{
+        ...await super.requiredArtifacts,
+        ELinuxDevelopmentArtifact.elinux,
+      };
+}
 
 /// See: [DevelopmentArtifact] in `cache.dart`
 class ELinuxDevelopmentArtifact implements DevelopmentArtifact {

lib/executable.dart

@@ -11,6 +11,7 @@ import 'dart:io';
 import 'package:flutter_tools/executable.dart' as flutter;
 import 'package:flutter_tools/runner.dart' as runner;
 import 'package:flutter_tools/src/application_package.dart';
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/context.dart';
 import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/template.dart';
@@ -48,6 +49,7 @@ import 'elinux_cache.dart';
 import 'elinux_device_discovery.dart';
 import 'elinux_doctor.dart';
 import 'elinux_package.dart';
+import 'elinux_artifacts.dart';
 
 /// Main entry point for commands.
 ///
@@ -127,6 +129,12 @@ Future<void> main(List<String> args) async {
           ),
       TemplateRenderer: () => const MustacheTemplateRenderer(),
       ApplicationPackageFactory: () => ELinuxApplicationPackageFactory(),
+      Artifacts: () => ELinuxArtifacts(
+            fileSystem: globals.fs,
+            cache: globals.cache,
+            platform: globals.platform,
+            operatingSystemUtils: globals.os,
+          ),
       DeviceManager: () => ELinuxDeviceManager(),
       DoctorValidatorsProvider: () => ELinuxDoctorValidatorsProvider(),
       ELinuxWorkflow: () => ELinuxWorkflow(