Reorganize leak tracking code. (#4832)

Author: polina-c

packages/devtools_app/lib/src/screens/memory/panes/leaks/controller.dart

@@ -0,0 +1,203 @@
+// Copyright 2022 The Chromium 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:async';
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:vm_service/vm_service.dart';
+
+import '../../../../config_specific/import_export/import_export.dart';
+import '../../../../config_specific/logger/logger.dart' as logger;
+import '../../../../primitives/utils.dart';
+import '../../../../service/service_extensions.dart';
+import '../../../../shared/globals.dart';
+import '../../primitives/memory_utils.dart';
+import 'diagnostics/formatter.dart';
+import 'diagnostics/leak_analyzer.dart';
+import 'diagnostics/model.dart';
+import 'instrumentation/model.dart';
+import 'primitives/analysis_status.dart';
+
+// TODO(polina-c): reference these constants in dart SDK, when it gets submitted
+// there.
+// https://github.com/flutter/devtools/issues/3951
+const _extensionKindToReceiveLeaksSummary = 'memory_leaks_summary';
+const _extensionKindToReceiveLeaksDetails = 'memory_leaks_details';
+
+const yamlFilePrefix = 'memory_leaks';
+
+class LeaksPaneController {
+  LeaksPaneController() {
+    _subscribeForMemoryLeaksMessages();
+  }
+
+  final status = AnalysisStatusController();
+
+  final leakSummaryHistory = ValueNotifier<String>('');
+  final leakSummaryReceived = ValueNotifier<bool>(false);
+  LeakSummary? _lastLeakSummary;
+
+  final _exportController = ExportController();
+
+  late StreamSubscription summarySubscription;
+  late StreamSubscription detailsSubscription;
+
+  /// Subscribes for summary with history and for details without history.
+  void _subscribeForMemoryLeaksMessages() {
+    detailsSubscription =
+        serviceManager.service!.onExtensionEvent.listen(_receivedLeaksDetails);
+
+    summarySubscription = serviceManager.service!.onExtensionEventWithHistory
+        .listen(_receivedLeaksSummary);
+  }
+
+  void dispose() {
+    unawaited(summarySubscription.cancel());
+    unawaited(detailsSubscription.cancel());
+    status.dispose();
+  }
+
+  void _receivedLeaksSummary(Event event) {
+    if (event.extensionKind != _extensionKindToReceiveLeaksSummary) return;
+    leakSummaryReceived.value = true;
+    try {
+      final newSummary = LeakSummary.fromJson(event.json!['extensionData']!);
+      final time = event.timestamp != null
+          ? DateTime.fromMicrosecondsSinceEpoch(event.timestamp!)
+          : DateTime.now();
+
+      if (newSummary.matches(_lastLeakSummary)) return;
+      _lastLeakSummary = newSummary;
+      leakSummaryHistory.value =
+          '${formatDateTime(time)}: ${newSummary.toMessage()}\n'
+          '${leakSummaryHistory.value}';
+    } catch (error, trace) {
+      leakSummaryHistory.value = 'error: $error\n${leakSummaryHistory.value}';
+      logger.log(error);
+      logger.log(trace);
+    }
+  }
+
+  Future<NotGCedAnalyzerTask> _createAnalysisTask(
+    List<LeakReport> reports,
+  ) async {
+    final graph = (await snapshotMemory())!;
+    return NotGCedAnalyzerTask.fromSnapshot(graph, reports);
+  }
+
+  Future<void> _receivedLeaksDetails(Event event) async {
+    if (event.extensionKind != _extensionKindToReceiveLeaksDetails) return;
+    if (status.status.value != AnalysisStatus.Ongoing) return;
+    NotGCedAnalyzerTask? task;
+
+    try {
+      await _setMessageWithDelay('Received details. Parsing...');
+      final leakDetails = Leaks.fromJson(event.json!['extensionData']!);
+
+      final notGCed = leakDetails.byType[LeakType.notGCed] ?? [];
+
+      NotGCedAnalyzed? notGCedAnalyzed;
+      if (notGCed.isNotEmpty) {
+        await _setMessageWithDelay('Taking heap snapshot...');
+        task = await _createAnalysisTask(notGCed);
+        await _setMessageWithDelay('Detecting retaining paths...');
+        notGCedAnalyzed = analyseNotGCed(task);
+      }
+
+      await _setMessageWithDelay('Formatting...');
+
+      final yaml = analyzedLeaksToYaml(
+        gcedLate: leakDetails.gcedLate,
+        notDisposed: leakDetails.notDisposed,
+        notGCed: notGCedAnalyzed,
+      );
+
+      _saveResultAndSetStatus(yaml, task);
+    } catch (error, trace) {
+      var message = '${status.message.value}\nError: $error';
+      if (task != null) {
+        final fileName = _saveTask(task, DateTime.now());
+        message += '\nDownloaded raw data to $fileName.';
+        await _setMessageWithDelay(message);
+        status.status.value = AnalysisStatus.ShowingError;
+      }
+      logger.log(error);
+      logger.log(trace);
+    }
+  }
+
+  void _saveResultAndSetStatus(String yaml, NotGCedAnalyzerTask? task) async {
+    final now = DateTime.now();
+    final yamlFile = ExportController.generateFileName(
+      time: now,
+      prefix: yamlFilePrefix,
+      type: ExportFileType.yaml,
+    );
+    _exportController.downloadFile(yaml, fileName: yamlFile);
+    final String? taskFile = _saveTask(task, now);
+
+    final taskFileMessage = taskFile == null ? '' : ' and $taskFile';
+    await _setMessageWithDelay(
+      'Downloaded the leak analysis to $yamlFile$taskFileMessage.',
+    );
+    status.status.value = AnalysisStatus.ShowingResult;
+  }
+
+  /// Saves raw analysis task for troubleshooting and deeper analysis.
+  String? _saveTask(NotGCedAnalyzerTask? task, DateTime? now) {
+    if (task == null) return null;
+
+    final json = jsonEncode(task.toJson());
+    final jsonFile = ExportController.generateFileName(
+      time: now,
+      prefix: yamlFilePrefix,
+      postfix: '.raw',
+      type: ExportFileType.json,
+    );
+    return _exportController.downloadFile(json, fileName: jsonFile);
+  }
+
+  Future<void> _setMessageWithDelay(String message) async {
+    status.message.value = message;
+    await delayForBatchProcessing(micros: 5000);
+  }
+
+  Future<void> forceGC() async {
+    status.status.value = AnalysisStatus.Ongoing;
+    await _setMessageWithDelay('Forcing full garbage collection...');
+    await _invokeMemoryLeakTrackingExtension(
+      <String, dynamic>{
+        // TODO(polina-c): reference the constant in Flutter
+        // https://github.com/flutter/devtools/issues/3951
+        'forceGC': 'true',
+      },
+    );
+    status.status.value = AnalysisStatus.ShowingResult;
+    await _setMessageWithDelay('Full garbage collection initiated.');
+  }
+
+  Future<void> requestLeaks() async {
+    status.status.value = AnalysisStatus.Ongoing;
+    await _setMessageWithDelay('Requested details from the application.');
+
+    await _invokeMemoryLeakTrackingExtension(
+      <String, dynamic>{
+        // TODO(polina-c): reference the constant in Flutter
+        // https://github.com/flutter/devtools/issues/3951
+        'requestDetails': 'true',
+      },
+    );
+  }
+
+  Future<void> _invokeMemoryLeakTrackingExtension(
+    Map<String, dynamic> args,
+  ) async {
+    await serviceManager.service!.callServiceExtension(
+      memoryLeakTracking,
+      isolateId: serviceManager.isolateManager.mainIsolate.value!.id!,
+      args: args,
+    );
+  }
+}

packages/devtools_app/lib/src/screens/memory/panes/leaks/formatter.dart renamed to packages/devtools_app/lib/src/screens/memory/panes/leaks/diagnostics/formatter.dart

@@ -4,8 +4,8 @@
 
 import 'package:collection/collection.dart';
 
-import 'diagnostics/model.dart';
-import 'instrumentation/model.dart';
+import '../instrumentation/model.dart';
+import 'model.dart';
 
 const linkToGuidance =
     'https://github.com/flutter/devtools/blob/master/packages/devtools_app/lib/src/screens/memory/panes/leaks/LEAK_TRACKING.md';