Add releaseMemory functionality to DevTools screen controllers

packages/devtools_app/lib/src/screens/app_size/app_size_controller.dart

@@ -11,6 +11,8 @@ import 'package:vm_snapshot_analysis/utils.dart';
 import 'package:vm_snapshot_analysis/v8_profile.dart';
 
 import '../../shared/charts/treemap.dart';
+import '../../shared/feature_flags.dart';
+import '../../shared/framework/screen.dart';
 import '../../shared/framework/screen_controllers.dart';
 import '../../shared/primitives/utils.dart';
 import '../../shared/table/table.dart';
@@ -85,6 +87,9 @@ class DiffTreeMap {
 /// `screenControllers`. The `dispose` method is called by `screenControllers`
 /// when DevTools is destroying a set of DevTools screen controllers.
 class AppSizeController extends DevToolsScreenController {
+  @override
+  final screenId = ScreenMetaData.appSize.id;
+
   static const unsupportedFileTypeError =
       'Failed to load size analysis file: file type not supported.\n\n'
       'The app size tool supports Dart AOT v8 snapshots, instruction sizes, '
@@ -766,6 +771,16 @@ class AppSizeController extends DevToolsScreenController {
     _processingNotifier.dispose();
     super.dispose();
   }
+
+  @override
+  void releaseMemory({bool partial = false}) {
+    if (FeatureFlags.memoryObserver) {
+      // This behavior is the same regardless of the value of `partial`. We can
+      // implement a partial clearing if it becomes necessary.
+      clear(AppSizeScreen.analysisTabKey);
+      clear(AppSizeScreen.diffTabKey);
+    }
+  }
 }
 
 extension AppSizeJsonFileExtension on DevToolsJsonFile {

packages/devtools_app/lib/src/screens/debugger/debugger_controller.dart

@@ -21,6 +21,7 @@ import '../../shared/diagnostics/primitives/source_location.dart';
 import '../../shared/diagnostics/tree_builder.dart';
 import '../../shared/feature_flags.dart';
 import '../../shared/framework/routing.dart';
+import '../../shared/framework/screen.dart';
 import '../../shared/framework/screen_controllers.dart';
 import '../../shared/globals.dart';
 import '../../shared/primitives/message_bus.dart';
@@ -58,6 +59,9 @@ class DebuggerController extends DevToolsScreenController
     }
   }
 
+  @override
+  final screenId = ScreenMetaData.debugger.id;
+
   @override
   void init() {
     super.init();

packages/devtools_app/lib/src/screens/deep_link_validation/deep_links_controller.dart

@@ -14,6 +14,7 @@ import '../../shared/analytics/analytics.dart' as ga;
 import '../../shared/analytics/constants.dart' as gac;
 import '../../shared/analytics/metrics.dart';
 import '../../shared/feature_flags.dart';
+import '../../shared/framework/screen.dart';
 import '../../shared/framework/screen_controllers.dart';
 import '../../shared/globals.dart';
 import '../../shared/primitives/utils.dart';
@@ -158,6 +159,9 @@ class DisplayOptions {
 /// when DevTools is destroying a set of DevTools screen controllers.
 class DeepLinksController extends DevToolsScreenController
     with AutoDisposeControllerMixin {
+  @override
+  final screenId = ScreenMetaData.deepLinks.id;
+
   @override
   void dispose() {
     _selectedAndroidVariantIndex.dispose();

packages/devtools_app/lib/src/screens/inspector_shared/inspector_screen_controller.dart

@@ -4,6 +4,7 @@
 
 import '../../shared/analytics/metrics.dart';
 import '../../shared/console/primitives/simple_items.dart';
+import '../../shared/framework/screen.dart';
 import '../../shared/framework/screen_controllers.dart';
 import '../inspector/inspector_controller.dart' as legacy;
 import '../inspector/inspector_tree_controller.dart' as legacy;
@@ -21,6 +22,9 @@ import '../inspector_v2/inspector_tree_controller.dart' as v2;
 /// `screenControllers`. The `dispose` method is called by `screenControllers`
 /// when DevTools is destroying a set of DevTools screen controllers.
 class InspectorScreenController extends DevToolsScreenController {
+  @override
+  final screenId = ScreenMetaData.inspector.id;
+
   late v2.InspectorController v2InspectorController;
   late v2.InspectorTreeController v2InspectorTreeController;
 

packages/devtools_app/lib/src/screens/logging/logging_controller.dart

@@ -18,7 +18,9 @@ import 'package:vm_service/vm_service.dart';
 import '../../service/vm_service_wrapper.dart';
 import '../../shared/diagnostics/diagnostics_node.dart';
 import '../../shared/diagnostics/inspector_service.dart';
+import '../../shared/feature_flags.dart';
 import '../../shared/framework/app_error_handling.dart' as error_handling;
+import '../../shared/framework/screen.dart';
 import '../../shared/framework/screen_controllers.dart';
 import '../../shared/globals.dart';
 import '../../shared/primitives/byte_utils.dart';
@@ -98,6 +100,9 @@ class LoggingController extends DevToolsScreenController
         SearchControllerMixin<LogData>,
         FilterControllerMixin<LogData>,
         AutoDisposeControllerMixin {
+  @override
+  final screenId = ScreenMetaData.logging.id;
+
   static const _minLogLevelFilterId = 'min-log-level';
   static const _verboseFlutterFrameworkFilterId = 'verbose-flutter-framework';
   static const _verboseFlutterServiceFilterId = 'verbose-flutter-service';
@@ -787,6 +792,18 @@ class LoggingController extends DevToolsScreenController
         data.where((log) => includeLogForFilter(log, filter: filter)).toList(),
       );
   }
+
+  @override
+  void releaseMemory({bool partial = false}) {
+    if (FeatureFlags.memoryObserver) {
+      if (partial) {
+        // Trim logs from the front so that the oldest logs are removed.
+        _updateData(data.sublist(data.length ~/ 2));
+      } else {
+        clear();
+      }
+    }
+  }
 }
 
 extension type _LogRecord(Map<String, dynamic> json) {

packages/devtools_app/lib/src/screens/memory/framework/memory_controller.dart

@@ -10,6 +10,7 @@ import 'dart:async';
 import 'package:devtools_app_shared/utils.dart';
 import 'package:flutter/foundation.dart';
 
+import '../../../shared/feature_flags.dart';
 import '../../../shared/framework/screen.dart';
 import '../../../shared/framework/screen_controllers.dart';
 import '../../../shared/globals.dart';
@@ -39,6 +40,9 @@ class MemoryController extends DevToolsScreenController
     with
         AutoDisposeControllerMixin,
         OfflineScreenControllerMixin<OfflineMemoryData> {
+  @override
+  final screenId = ScreenMetaData.memory.id;
+
   Future<void> get initialized => _initialized.future;
   final _initialized = Completer<void>();
 
@@ -210,4 +214,14 @@ class MemoryController extends DevToolsScreenController
       _gcing.value = false;
     }
   }
+
+  @override
+  FutureOr<void> releaseMemory({bool partial = false}) async {
+    if (FeatureFlags.memoryObserver) {
+      diff.clearSnapshots(partial: partial);
+      // Clear all allocation traces since the traces form a single tracing
+      // profile.
+      await trace?.clear();
+    }
+  }
 }

packages/devtools_app/lib/src/screens/memory/panes/diff/controller/diff_pane_controller.dart

@@ -151,12 +151,24 @@ class DiffPaneController extends DisposableController with Serializable {
     }
   }
 
-  void clearSnapshots() {
+  void clearSnapshots({bool partial = false}) {
+    const offsetForInstructionSnapshot = 1;
     final snapshots = core._snapshots;
-    for (var i = 1; i < snapshots.value.length; i++) {
+    final snapshotsToRemove = max(
+      offsetForInstructionSnapshot,
+      (snapshots.value.length - offsetForInstructionSnapshot) ~/
+          (partial ? 2 : 1),
+    );
+    final endIndexToRemoveExclusive =
+        offsetForInstructionSnapshot + snapshotsToRemove;
+    for (
+      var i = offsetForInstructionSnapshot;
+      i < endIndexToRemoveExclusive;
+      i++
+    ) {
       snapshots.value[i].dispose();
     }
-    snapshots.removeRange(1, snapshots.value.length);
+    snapshots.removeRange(1, endIndexToRemoveExclusive);
     core._selectedSnapshotIndex.value = 0;
     derived._updateValues();
   }

packages/devtools_app/lib/src/screens/network/network_controller.dart

@@ -11,6 +11,8 @@ import 'package:vm_service/vm_service.dart';
 
 import '../../shared/config_specific/import_export/import_export.dart';
 import '../../shared/config_specific/logger/allowed_error.dart';
+import '../../shared/feature_flags.dart';
+import '../../shared/framework/screen.dart';
 import '../../shared/framework/screen_controllers.dart';
 import '../../shared/globals.dart';
 import '../../shared/http/http_request_data.dart';
@@ -61,6 +63,9 @@ class NetworkController extends DevToolsScreenController
         FilterControllerMixin<NetworkRequest>,
         OfflineScreenControllerMixin,
         AutoDisposeControllerMixin {
+  @override
+  final screenId = ScreenMetaData.network.id;
+
   List<DartIOHttpRequestData>? _httpRequests;
 
   Future<String?> exportAsHarFile() async {
@@ -392,9 +397,11 @@ class NetworkController extends DevToolsScreenController
 
   /// Clears the HTTP profile and socket profile from the vm, and resets the
   /// last refresh timestamp to the current time.
-  Future<void> clear() async {
-    await networkService.clearData();
-    _currentNetworkRequests.clear();
+  Future<void> clear({bool partial = false}) async {
+    if (!partial) {
+      await networkService.clearData();
+    }
+    _currentNetworkRequests.clear(partial: partial);
     _filterAndRefreshSearchMatches();
     _updateSelection();
   }
@@ -507,6 +514,13 @@ class NetworkController extends DevToolsScreenController
           .whereType<DartIOHttpRequestData>()
           .map((item) => item.getFullRequestData())
           .wait;
+
+  @override
+  FutureOr<void> releaseMemory({bool partial = false}) async {
+    if (FeatureFlags.memoryObserver) {
+      await clear(partial: partial);
+    }
+  }
 }
 
 /// Class for managing the set of all current sockets, and
@@ -589,9 +603,19 @@ class CurrentNetworkRequests extends ValueNotifier<List<NetworkRequest>> {
     }
   }
 
-  void clear() {
-    _requestsById.clear();
-    value = [];
-    notifyListeners();
+  void clear({bool partial = false}) {
+    if (partial) {
+      _requestsById.keys
+          .toList()
+          // Trim requests from the front so that the oldest data is removed.
+          .sublist(0, _requestsById.keys.length ~/ 2)
+          .forEach(_requestsById.remove);
+      value = value.sublist(value.length ~/ 2);
+      notifyListeners();
+    } else {
+      _requestsById.clear();
+      value = [];
+      notifyListeners();
+    }
   }
 }

packages/devtools_app/lib/src/screens/performance/panes/flutter_frames/flutter_frames_controller.dart

@@ -171,8 +171,13 @@ class FlutterFramesController extends PerformanceFeatureController {
   }
 
   @override
-  void clearData() {
-    _flutterFrames.clear();
+  void clearData({bool partial = false}) {
+    if (partial) {
+      // Trim frames from the front so that the oldest logs are removed.
+      _flutterFrames.trimToSublist(_flutterFrames.value.length ~/ 2);
+    } else {
+      _flutterFrames.clear();
+    }
     _unassignedFlutterFrames.clear();
     firstWellFormedFrameMicros = null;
     _selectedFrameNotifier.value = null;

packages/devtools_app/lib/src/screens/performance/panes/rebuild_stats/rebuild_stats_controller.dart

@@ -16,7 +16,7 @@ class RebuildStatsController extends PerformanceFeatureController {
   RebuildStatsController(super.performanceController);
 
   @override
-  FutureOr<void> clearData() {}
+  void clearData({bool partial = false}) {}
 
   @override
   void handleSelectedFrame(FlutterFrame frame) {}

packages/devtools_app/lib/src/screens/performance/panes/timeline_events/timeline_events_controller.dart

@@ -513,15 +513,24 @@ class TimelineEventsController extends PerformanceFeatureController
   }
 
   @override
-  Future<void> clearData() async {
-    _unprocessedTrackEvents.clear();
-    traceRingBuffer.clear();
-    _trackDescriptors.clear();
-    _unassignedFlutterTimelineEvents.clear();
-
-    _refreshWorkTracker.clear();
-    _status.value = EventsControllerStatus.empty;
-    await perfettoController.clear();
+  Future<void> clearData({bool partial = false}) async {
+    if (partial) {
+      if (traceRingBuffer.chunksLength <= 1) {
+        traceRingBuffer.clear();
+      } else {
+        // Trim from the front so that the oldest data is removed.
+        traceRingBuffer.trimToSublist(traceRingBuffer.chunksLength ~/ 2);
+      }
+      unawaited(loadPerfettoTrace());
+    } else {
+      traceRingBuffer.clear();
+      _unprocessedTrackEvents.clear();
+      _trackDescriptors.clear();
+      _unassignedFlutterTimelineEvents.clear();
+      _refreshWorkTracker.clear();
+      _status.value = EventsControllerStatus.empty;
+      await perfettoController.clear();
+    }
   }
 
   @override

packages/devtools_app/lib/src/screens/performance/performance_controller.dart

@@ -11,6 +11,7 @@ import 'package:vm_service/vm_service.dart';
 import '../../service/service_registrations.dart' as registrations;
 import '../../shared/diagnostics/inspector_service.dart';
 import '../../shared/feature_flags.dart';
+import '../../shared/framework/screen.dart';
 import '../../shared/framework/screen_controllers.dart';
 import '../../shared/globals.dart';
 import '../../shared/offline/offline_data.dart';
@@ -41,6 +42,9 @@ class PerformanceController extends DevToolsScreenController
     with
         AutoDisposeControllerMixin,
         OfflineScreenControllerMixin<OfflinePerformanceData> {
+  @override
+  final screenId = ScreenMetaData.performance.id;
+
   late final FlutterFramesController flutterFramesController;
 
   late final TimelineEventsController timelineEventsController;
@@ -240,13 +244,17 @@ class PerformanceController extends DevToolsScreenController
 
   /// Clears the timeline data currently stored by the controller as well the
   /// VM timeline if a connected app is present.
-  Future<void> clearData() async {
-    if (serviceConnection.serviceManager.connectedAppInitialized) {
+  Future<void> clearData({
+    bool partial = false,
+    bool clearVmTimeline = true,
+  }) async {
+    if (serviceConnection.serviceManager.connectedAppInitialized &&
+        clearVmTimeline) {
       await serviceConnection.serviceManager.service!.clearVMTimeline();
     }
     offlinePerformanceData = null;
     serviceConnection.errorBadgeManager.clearErrors(PerformanceScreen.id);
-    await _applyToFeatureControllersAsync((c) => c.clearData());
+    await _applyToFeatureControllersAsync((c) => c.clearData(partial: partial));
   }
 
   @override
@@ -269,6 +277,13 @@ class PerformanceController extends DevToolsScreenController
           displayRefreshRate: flutterFramesController.displayRefreshRate.value,
         ).toJson(),
   );
+
+  @override
+  FutureOr<void> releaseMemory({bool partial = false}) async {
+    if (FeatureFlags.memoryObserver) {
+      await clearData(partial: partial, clearVmTimeline: !partial);
+    }
+  }
 }
 
 abstract class PerformanceFeatureController extends DisposableController {
@@ -294,7 +309,7 @@ abstract class PerformanceFeatureController extends DisposableController {
 
   Future<void> setOfflineData(OfflinePerformanceData offlineData);
 
-  FutureOr<void> clearData();
+  FutureOr<void> clearData({bool partial = false});
 
   void handleSelectedFrame(FlutterFrame frame);
 }