Load a snapshot. (#6974)

packages/.vscode/extensions.json

@@ -0,0 +1,5 @@
+{
+    "recommendations": [
+        "streetsidesoftware.code-spell-checker"
+    ]
+}

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

@@ -27,8 +27,8 @@ class MemoryFeatureControllers {
     ProfilePaneController? profilePaneController,
   ) {
     memoryTimeline = MemoryTimeline();
-    diff =
-        diffPaneController ?? DiffPaneController(SnapshotTaker(memoryTimeline));
+    diff = diffPaneController ??
+        DiffPaneController(SnapshotTakerRuntime(memoryTimeline));
     profile = profilePaneController ?? ProfilePaneController();
   }
 
@@ -39,7 +39,7 @@ class MemoryFeatureControllers {
 
   void reset() {
     diff.dispose();
-    diff = DiffPaneController(SnapshotTaker(memoryTimeline));
+    diff = DiffPaneController(SnapshotTakerRuntime(memoryTimeline));
 
     profile.dispose();
     profile = ProfilePaneController();
@@ -210,7 +210,7 @@ class MemoryController extends DisposableController
 
     // TODO(terry): Used to detect stream being closed from the
     // memoryController dispose method.  Needed when a HOT RELOAD
-    // will call dispose however, spinup (initState) doesn't seem
+    // will call dispose however, initState doesn't seem
     // to happen David is working on scaffolding.
     _memoryTrackerController.stream.listen(
       (_) {},
@@ -290,7 +290,7 @@ class MemoryController extends DisposableController
     }
   }
 
-  /// Detect stale isolates (sentinaled), may happen after a hot restart.
+  /// Detect stale isolates (sentineled), may happen after a hot restart.
   Future<bool> isIsolateLive(String isolateId) async {
     try {
       final service = serviceConnection.serviceManager.service!;

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

@@ -12,6 +12,7 @@ import 'package:flutter/foundation.dart';
 import '../../../../../shared/analytics/analytics.dart' as ga;
 import '../../../../../shared/analytics/constants.dart' as gac;
 import '../../../../../shared/config_specific/import_export/import_export.dart';
+import '../../../../../shared/file_import.dart';
 import '../../../../../shared/globals.dart';
 import '../../../../../shared/memory/class_name.dart';
 import '../../../shared/heap/class_filter.dart';
@@ -28,10 +29,6 @@ class DiffPaneController extends DisposableController {
 
   final SnapshotTaker snapshotTaker;
 
-  /// If true, a snapshot is being taken.
-  ValueListenable<bool> get isTakingSnapshot => _isTakingSnapshot;
-  final _isTakingSnapshot = ValueNotifier<bool>(false);
-
   final retainingPathController = RetainingPathController();
 
   final core = CoreData();
@@ -42,17 +39,43 @@ class DiffPaneController extends DisposableController {
   bool get hasSnapshots => core.snapshots.value.length > 1;
 
   Future<void> takeSnapshot() async {
-    _isTakingSnapshot.value = true;
     ga.select(
       gac.memory,
       gac.MemoryEvent.diffTakeSnapshotControlPane,
     );
 
     final item = SnapshotInstanceItem(
       displayNumber: _nextDisplayNumber(),
-      isolateName: selectedIsolateName ?? '<isolate-not-detected>',
+      defaultName: selectedIsolateName ?? '<isolate-not-detected>',
+    );
+
+    await _addSnapshot(snapshotTaker, item);
+    derived._updateValues();
+  }
+
+  /// Imports snapshots from files.
+  ///
+  /// Opens file selector and loads snapshots from the selected files.
+  Future<void> importSnapshots() async {
+    ga.select(
+      gac.memory,
+      gac.importFile,
     );
+    final files = await importRawFilesFromPicker();
+    if (files.isEmpty) return;
+
+    final importers = files.map((file) async {
+      final item = SnapshotInstanceItem(defaultName: file.name);
+      await _addSnapshot(SnapshotTakerFromFile(file), item);
+    });
+    await Future.wait(importers);
+    derived._updateValues();
+  }
 
+  Future<void> _addSnapshot(
+    SnapshotTaker snapshotTaker,
+    SnapshotInstanceItem item,
+  ) async {
     final snapshots = core._snapshots;
     snapshots.add(item);
 
@@ -65,8 +88,6 @@ class DiffPaneController extends DisposableController {
     } finally {
       final newElementIndex = snapshots.value.length - 1;
       core._selectedSnapshotIndex.value = newElementIndex;
-      _isTakingSnapshot.value = false;
-      derived._updateValues();
     }
   }
 
@@ -81,7 +102,7 @@ class DiffPaneController extends DisposableController {
   }
 
   int _nextDisplayNumber() {
-    final numbers = core._snapshots.value.map((e) => e.displayNumber);
+    final numbers = core._snapshots.value.map((e) => e.displayNumber ?? 0);
     assert(numbers.isNotEmpty);
     return numbers.max + 1;
   }

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

@@ -9,10 +9,8 @@ import '../../../../../shared/memory/adapted_heap_data.dart';
 import '../../../shared/heap/heap.dart';
 
 abstract class SnapshotItem extends DisposableController {
-  /// Number, that if shown in name, should be unique in the list.
-  ///
-  /// If the number is not expected to be shown in UI, it should be 0.
-  int get displayNumber;
+  /// Number to show with auto-generated names that may be non unique, like isolate name.
+  int? get displayNumber;
 
   ValueListenable<bool> get isProcessing => _isProcessing;
   final _isProcessing = ValueNotifier<bool>(false);
@@ -23,21 +21,22 @@ abstract class SnapshotItem extends DisposableController {
 
 class SnapshotDocItem extends SnapshotItem {
   @override
-  int get displayNumber => 0;
+  int? get displayNumber => null;
 
   @override
   bool get hasData => false;
 }
 
 class SnapshotInstanceItem extends SnapshotItem {
   SnapshotInstanceItem({
-    required this.displayNumber,
-    required this.isolateName,
+    this.displayNumber,
+    required this.defaultName,
   }) {
     _isProcessing.value = true;
   }
 
-  final String isolateName;
+  /// Automatically assigned name like isolate name or file name.
+  final String defaultName;
 
   AdaptedHeap? heap;
 
@@ -52,9 +51,11 @@ class SnapshotInstanceItem extends SnapshotItem {
   }
 
   @override
-  final int displayNumber;
+  final int? displayNumber;
 
-  String get name => nameOverride ?? '$isolateName-$displayNumber';
+  String get name =>
+      nameOverride ??
+      '$defaultName${displayNumber == null ? '' : '-$displayNumber'}';
 
   String? nameOverride;
 

packages/devtools_app/lib/src/screens/memory/panes/diff/diff_pane.dart

@@ -11,6 +11,7 @@ import 'package:flutter_markdown/flutter_markdown.dart';
 import '../../../../shared/analytics/constants.dart' as gac;
 import '../../../../shared/common_widgets.dart';
 import '../../../../shared/config_specific/launch_url/launch_url.dart';
+import '../../../../shared/globals.dart';
 import '../../../../shared/primitives/simple_items.dart';
 import '../../shared/widgets/shared_memory_widgets.dart';
 import 'controller/diff_pane_controller.dart';
@@ -68,7 +69,9 @@ class _SnapshotItemContent extends StatelessWidget {
                     children: [
                       Expanded(
                         child: Markdown(
-                          data: _snapshotDocumentation,
+                          data: _snapshotDocumentation(
+                            preferences.darkModeTheme.value,
+                          ),
                           styleSheet: MarkdownStyleSheet(
                             p: Theme.of(context).regularTextStyle,
                           ),
@@ -136,8 +139,12 @@ class SnapshotInstanceItemPane extends StatelessWidget {
   }
 }
 
-// `\v` adds vertical space
-const _snapshotDocumentation = '''
+String _snapshotDocumentation(bool isDark) {
+  final filePostfix = isDark ? 'dark' : 'light';
+  final uploadImageUrl = 'assets/img/doc/upload_$filePostfix.png';
+
+  // `\v` adds vertical space
+  return '''
 Find unexpected memory usage by comparing two heap snapshots:
 
 \v
@@ -146,9 +153,18 @@ Find unexpected memory usage by comparing two heap snapshots:
 
 \v
 
-2. Take a **heap snapshot** to view current memory allocation:
+2. Use one of the following ways to get a **heap snapshot**:
+
+    a. To view current memory allocation click the ● button
 
-    a. In the Snapshots panel, click the ● button
+    b. To import a snapshot taken with
+    [auto-snapshotting](https://github.com/dart-lang/leak_tracker/blob/main/doc/USAGE.md) or
+    [writeHeapSnapshotToFile](https://api.flutter.dev/flutter/dart-developer/NativeRuntime/writeHeapSnapshotToFile.html)
+    click the ![import]($uploadImageUrl) button
+
+\v
+
+3. Review the snapshot:
 
     b. If you want to refine results, use the **Filter** button
 
@@ -158,19 +174,17 @@ Find unexpected memory usage by comparing two heap snapshots:
 
 \v
 
-3. Check the **diff** between snapshots to detect allocation issues:
-
-    a. Take a **snapshot**
+4. Check the **diff** between snapshots to detect allocation issues:
 
-    b. Execute the feature in your application
-
-    c. Take a second snapshot. If you are experiencing DevTools crashes due to size of snapshots,
+    a. Get **snapshots** before and after a feature execution.
+       If you are experiencing DevTools crashes due to size of snapshots,
        switch to the [desktop version](https://github.com/flutter/devtools/blob/master/BETA_TESTING.md).
 
-    d. While viewing the second snapshot, click **Diff with:** and select the first snapshot from the drop-down menu;
+    b. While viewing the second snapshot, click **Diff with:** and select the first snapshot from the drop-down menu;
     the results area will display the diff
 
-    e. Use the **Filter** button to refine the diff results, if needed
+    c. Use the **Filter** button to refine the diff results, if needed
 
-    f. Select a class from the diff to view its retaining paths, and see which objects hold the references to those instances
+    d. Select a class from the diff to view its retaining paths, and see which objects hold the references to those instances
 ''';
+}

packages/devtools_app/lib/src/screens/memory/panes/diff/widgets/snapshot_control_pane.dart

@@ -22,44 +22,39 @@ class SnapshotControlPane extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return ValueListenableBuilder<bool>(
-      valueListenable: controller.isTakingSnapshot,
-      builder: (_, isProcessing, __) {
-        final current = controller.core.selectedItem as SnapshotInstanceItem;
-        final heapIsReady = !isProcessing && current.heap != null;
-        if (heapIsReady) {
-          return Row(
-            mainAxisAlignment: MainAxisAlignment.spaceBetween,
+    final current = controller.core.selectedItem as SnapshotInstanceItem;
+    final heapIsReady = current.heap != null;
+    if (heapIsReady) {
+      return Row(
+        mainAxisAlignment: MainAxisAlignment.spaceBetween,
+        children: [
+          Row(
             children: [
-              Row(
-                children: [
-                  _DiffDropdown(
-                    current: current,
-                    controller: controller,
-                  ),
-                  const SizedBox(width: defaultSpacing),
-                  DownloadButton(
-                    tooltip: 'Download data in CSV format',
-                    label: 'CSV',
-                    minScreenWidthForTextBeforeScaling:
-                        memoryControlsMinVerboseWidth,
-                    gaScreen: gac.memory,
-                    gaSelection: gac.MemoryEvent.diffSnapshotDownloadCsv,
-                    onPressed: controller.downloadCurrentItemToCsv,
-                  ),
-                ],
+              _DiffDropdown(
+                current: current,
+                controller: controller,
               ),
-              Expanded(
-                child: _SnapshotSizeView(
-                  footprint: current.heap!.footprint,
-                ),
+              const SizedBox(width: defaultSpacing),
+              DownloadButton(
+                tooltip: 'Download data in CSV format',
+                label: 'CSV',
+                minScreenWidthForTextBeforeScaling:
+                    memoryControlsMinVerboseWidth,
+                gaScreen: gac.memory,
+                gaSelection: gac.MemoryEvent.diffSnapshotDownloadCsv,
+                onPressed: controller.downloadCurrentItemToCsv,
               ),
             ],
-          );
-        }
-        return const SizedBox.shrink();
-      },
-    );
+          ),
+          Expanded(
+            child: _SnapshotSizeView(
+              footprint: current.heap!.footprint,
+            ),
+          ),
+        ],
+      );
+    }
+    return const SizedBox.shrink();
   }
 }