Invalidate caches after a hot reload

dwds/CHANGELOG.md

@@ -1,6 +1,7 @@
-## 24.4.0-wip
+## 24.4.0
 
 - Added support for breakpoint registering on a hot reload with the DDC library bundle format using PausePostRequests.
+- `FrontendServerDdcLibraryBundleStrategy.hotReloadSourceUri` is now expected to also provide the reloaded modules.
 
 ## 24.3.11
 

dwds/lib/src/debugging/debugger.dart

@@ -594,6 +594,7 @@ class Debugger extends Domain {
             params: {
               'skipList': _skipLists.compute(
                 scriptId,
+                url,
                 await _locations.locationsForUrl(url),
               ),
             },

dwds/lib/src/debugging/inspector.dart

@@ -13,6 +13,7 @@ import 'package:dwds/src/debugging/execution_context.dart';
 import 'package:dwds/src/debugging/instance.dart';
 import 'package:dwds/src/debugging/libraries.dart';
 import 'package:dwds/src/debugging/location.dart';
+import 'package:dwds/src/debugging/metadata/provider.dart';
 import 'package:dwds/src/debugging/remote_debugger.dart';
 import 'package:dwds/src/loaders/ddc_library_bundle.dart';
 import 'package:dwds/src/readers/asset_reader.dart';
@@ -34,7 +35,9 @@ import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
 class AppInspector implements AppInspectorInterface {
   var _scriptCacheMemoizer = AsyncMemoizer<List<ScriptRef>>();
 
-  Future<List<ScriptRef>> get scriptRefs => _populateScriptCaches();
+  Future<List<ScriptRef>> getScriptRefs({
+    ModifiedModuleReport? modifiedModuleReport,
+  }) => _populateScriptCaches(modifiedModuleReport: modifiedModuleReport);
 
   final _logger = Logger('AppInspector');
 
@@ -103,24 +106,35 @@ class AppInspector implements AppInspectorInterface {
 
   /// Reset all caches and recompute any mappings.
   ///
-  /// Should be called across hot reloads.
-  Future<void> initialize() async {
+  /// Should be called across hot reloads with a valid [ModifiedModuleReport].
+  Future<void> initialize({ModifiedModuleReport? modifiedModuleReport}) async {
     _scriptCacheMemoizer = AsyncMemoizer<List<ScriptRef>>();
-    _scriptRefsById.clear();
-    _serverPathToScriptRef.clear();
-    _scriptIdToLibraryId.clear();
-    _libraryIdToScriptRefs.clear();
 
-    _libraryHelper = LibraryHelper(this);
+    // TODO(srujzs): We can invalidate these in a smarter way instead of
+    // reinitializing when doing a hot reload, but these helpers recompute info
+    // on demand later and therefore are not in the critical path.
     _classHelper = ClassHelper(this);
     _instanceHelper = InstanceHelper(this);
 
+    if (modifiedModuleReport != null) {
+      // Invalidate `_libraryHelper` as we use it populate any script caches.
+      _libraryHelper.initialize(modifiedModuleReport: modifiedModuleReport);
+    } else {
+      _libraryHelper = LibraryHelper(this)..initialize();
+      _scriptRefsById.clear();
+      _serverPathToScriptRef.clear();
+      _scriptIdToLibraryId.clear();
+      _libraryIdToScriptRefs.clear();
+    }
+
     final libraries = await _libraryHelper.libraryRefs;
     isolate.rootLib = await _libraryHelper.rootLib;
     isolate.libraries?.clear();
     isolate.libraries?.addAll(libraries);
 
-    final scripts = await scriptRefs;
+    final scripts = await getScriptRefs(
+      modifiedModuleReport: modifiedModuleReport,
+    );
 
     await DartUri.initialize();
     DartUri.recordAbsoluteUris(libraries.map((lib) => lib.uri).nonNulls);
@@ -583,7 +597,7 @@ class AppInspector implements AppInspectorInterface {
   /// All the scripts in the isolate.
   @override
   Future<ScriptList> getScripts() async {
-    return ScriptList(scripts: await scriptRefs);
+    return ScriptList(scripts: await getScriptRefs());
   }
 
   /// Calls the Chrome Runtime.getProperties API for the object with [objectId].
@@ -714,19 +728,50 @@ class AppInspector implements AppInspectorInterface {
   ///
   /// This will get repopulated on restarts and reloads.
   ///
+  /// If [modifiedModuleReport] is provided, only invalidates and
+  /// recalculates caches for the modified libraries.
+  ///
   /// Returns the list of scripts refs cached.
-  Future<List<ScriptRef>> _populateScriptCaches() {
+  Future<List<ScriptRef>> _populateScriptCaches({
+    ModifiedModuleReport? modifiedModuleReport,
+  }) {
     return _scriptCacheMemoizer.runOnce(() async {
       final scripts =
           await globalToolConfiguration.loadStrategy
               .metadataProviderFor(appConnection.request.entrypointPath)
               .scripts;
+      if (modifiedModuleReport != null) {
+        // Invalidate any script caches that were computed for the now invalid
+        // libraries. They will get repopulated below.
+        for (final libraryUri in modifiedModuleReport.modifiedLibraries) {
+          final libraryRef = await _libraryHelper.libraryRefFor(libraryUri);
+          final libraryId = libraryRef?.id;
+          // If this was not a pre-existing library, nothing to invalidate.
+          if (libraryId == null) continue;
+          final scriptRefs = _libraryIdToScriptRefs.remove(libraryId);
+          if (scriptRefs == null) continue;
+          for (final scriptRef in scriptRefs) {
+            final scriptId = scriptRef.id;
+            final scriptUri = scriptRef.uri;
+            if (scriptId != null && scriptUri != null) {
+              _scriptRefsById.remove(scriptId);
+              _scriptIdToLibraryId.remove(scriptId);
+              _serverPathToScriptRef.remove(
+                DartUri(scriptUri, _root).serverPath,
+              );
+            }
+          }
+        }
+      }
       // For all the non-dart: libraries, find their parts and create scriptRefs
       // for them.
       final userLibraries = _userLibraryUris(
         isolate.libraries ?? <LibraryRef>[],
       );
       for (final uri in userLibraries) {
+        if (modifiedModuleReport?.modifiedLibraries.contains(uri) == false) {
+          continue;
+        }
         final parts = scripts[uri];
         final scriptRefs = [
           ScriptRef(uri: uri, id: createId()),

dwds/lib/src/debugging/libraries.dart

@@ -5,6 +5,7 @@
 import 'package:collection/collection.dart';
 import 'package:dwds/src/config/tool_configuration.dart';
 import 'package:dwds/src/debugging/metadata/class.dart';
+import 'package:dwds/src/debugging/metadata/provider.dart';
 import 'package:dwds/src/services/chrome_debug_exception.dart';
 import 'package:dwds/src/utilities/domain.dart';
 import 'package:logging/logging.dart';
@@ -27,6 +28,29 @@ class LibraryHelper extends Domain {
     inspector = appInspector;
   }
 
+  /// Initialize any caches.
+  ///
+  /// If [modifiedModuleReport] is not null, invalidates only modified libraries
+  /// from the cache and recomputes values for any eager caches.
+  void initialize({ModifiedModuleReport? modifiedModuleReport}) {
+    _rootLib = null;
+    if (modifiedModuleReport != null) {
+      for (final library in modifiedModuleReport.modifiedLibraries) {
+        // These will later be initialized by `libraryFor` if needed.
+        _librariesById.remove(library);
+        _libraryRefsById.remove(library);
+      }
+      for (final library in modifiedModuleReport.reloadedLibraries) {
+        // These need to be recomputed here as `libraryRefs` only checks if this
+        // map is empty before returning.
+        _libraryRefsById[library] = _createLibraryRef(library);
+      }
+      return;
+    }
+    _librariesById.clear();
+    _libraryRefsById.clear();
+  }
+
   Future<LibraryRef> get rootLib async {
     if (_rootLib != null) return _rootLib!;
     final libraries = await libraryRefs;
@@ -51,21 +75,21 @@ class LibraryHelper extends Domain {
     return _rootLib!;
   }
 
+  LibraryRef _createLibraryRef(String library) =>
+      LibraryRef(id: library, name: library, uri: library);
+
   /// Returns all libraryRefs in the app.
   ///
-  /// Note this can return a cached result.
+  /// Note this can return a cached result that can be selectively reinitialized
+  /// using [initialize].
   Future<List<LibraryRef>> get libraryRefs async {
     if (_libraryRefsById.isNotEmpty) return _libraryRefsById.values.toList();
     final libraries =
         await globalToolConfiguration.loadStrategy
             .metadataProviderFor(inspector.appConnection.request.entrypointPath)
             .libraries;
     for (final library in libraries) {
-      _libraryRefsById[library] = LibraryRef(
-        id: library,
-        name: library,
-        uri: library,
-      );
+      _libraryRefsById[library] = _createLibraryRef(library);
     }
     return _libraryRefsById.values.toList();
   }

dwds/lib/src/debugging/location.dart

@@ -4,6 +4,7 @@
 
 import 'package:async/async.dart';
 import 'package:dwds/src/config/tool_configuration.dart';
+import 'package:dwds/src/debugging/metadata/provider.dart';
 import 'package:dwds/src/debugging/modules.dart';
 import 'package:dwds/src/readers/asset_reader.dart';
 import 'package:dwds/src/utilities/dart_uri.dart';
@@ -151,11 +152,34 @@ class Locations {
 
   Modules get modules => _modules;
 
-  void initialize(String entrypoint) {
-    _sourceToTokenPosTable.clear();
-    _sourceToLocation.clear();
+  /// Initialize any caches.
+  ///
+  /// If [modifiedModuleReport] is not null, only invalidates the caches for the
+  /// modified modules instead.
+  Future<void> initialize(
+    String entrypoint, {
+    ModifiedModuleReport? modifiedModuleReport,
+  }) async {
+    // If we know that only certain modules are deleted or added, we can only
+    // invalidate those.
+    if (modifiedModuleReport != null) {
+      for (final module in modifiedModuleReport.modifiedModules) {
+        _locationMemoizer.remove(module);
+        _moduleToLocations.remove(module);
+        final sources = await _modules.sourcesForModule(module);
+        if (sources != null) {
+          for (final serverPath in sources) {
+            _sourceToTokenPosTable.remove(serverPath);
+            _sourceToLocation.remove(serverPath);
+          }
+        }
+      }
+      return;
+    }
     _locationMemoizer.clear();
     _moduleToLocations.clear();
+    _sourceToTokenPosTable.clear();
+    _sourceToLocation.clear();
     _entrypoint = entrypoint;
   }