Bug 897954: Implement and apply purge-caches mechanism. r=mak

Differential Revision: https://phabricator.services.mozilla.com/D105440

dom/base/PlacesEvent.h

@@ -50,6 +50,9 @@ class PlacesEvent : public nsWrapperCache {
   virtual const PlacesVisitRemoved* AsPlacesVisitRemoved() const {
     return nullptr;
   }
+  virtual const PlacesPurgeCaches* AsPlacesPurgeCaches() const {
+    return nullptr;
+  }
 
  protected:
   virtual ~PlacesEvent() = default;

dom/base/PlacesPurgeCaches.h

@@ -0,0 +1,39 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_PlacesPurgeCaches_h
+#define mozilla_dom_PlacesPurgeCaches_h
+
+#include "mozilla/dom/PlacesEvent.h"
+
+namespace mozilla {
+namespace dom {
+
+class PlacesPurgeCaches final : public PlacesEvent {
+ public:
+  explicit PlacesPurgeCaches() : PlacesEvent(PlacesEventType::Purge_caches) {}
+
+  static already_AddRefed<PlacesPurgeCaches> Constructor(
+      const GlobalObject& aGlobal) {
+    RefPtr<PlacesPurgeCaches> event = new PlacesPurgeCaches();
+    return event.forget();
+  }
+
+  JSObject* WrapObject(JSContext* aCx,
+                       JS::Handle<JSObject*> aGivenProto) override {
+    return PlacesPurgeCaches_Binding::Wrap(aCx, this, aGivenProto);
+  }
+
+  const PlacesPurgeCaches* AsPlacesPurgeCaches() const override { return this; }
+
+ private:
+  ~PlacesPurgeCaches() = default;
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // mozilla_dom_PlacesPurgeCaches_h

dom/base/moz.build

@@ -223,6 +223,7 @@ EXPORTS.mozilla.dom += [
     "PlacesFavicon.h",
     "PlacesHistoryCleared.h",
     "PlacesObservers.h",
+    "PlacesPurgeCaches.h",
     "PlacesRanking.h",
     "PlacesVisit.h",
     "PlacesVisitRemoved.h",

dom/chrome-webidl/PlacesEvent.webidl

@@ -39,6 +39,12 @@ enum PlacesEventType {
    * bookmarked.
    */
   "page-removed",
+  /**
+   * data: PlacesPurgeCaches. Fired whenever changes happened that could not be observed
+   * through other notifications, for example a database fixup. When received, observers,
+   * especially data views, should drop any caches and reload from scratch.
+   */
+  "purge-caches",
 };
 
 [ChromeOnly, Exposed=Window]
@@ -328,4 +334,9 @@ interface PlacesVisitRemoved : PlacesEvent {
    * This will be true if remains at least one visit to the page.
    */
   readonly attribute boolean isPartialVisistsRemoval;
-};
+};
+
+[ChromeOnly, Exposed=Window]
+interface PlacesPurgeCaches : PlacesEvent {
+  constructor();
+};

services/sync/modules/engines/bookmarks.js

@@ -891,6 +891,10 @@ BookmarksTracker.prototype = {
           this._log.trace("'bookmark-removed': " + event.id);
           this._upScore();
           break;
+        case "purge-caches":
+          this._log.trace("purge-caches");
+          this._upScore();
+          break;
       }
     }
   },

toolkit/components/places/PlacesDBUtils.jsm

@@ -103,15 +103,7 @@ var PlacesDBUtils = {
    * @returns {Array} An empty array.
    */
   async _refreshUI() {
-    // Send batch update notifications to update the UI.
-    let observers = [
-      ...PlacesUtils.history.getObservers(),
-      ...PlacesUtils.bookmarks.getObservers(),
-    ];
-    for (let observer of observers) {
-      observer.onBeginUpdateBatch();
-      observer.onEndUpdateBatch();
-    }
+    PlacesObservers.notifyListeners([new PlacesPurgeCaches()]);
     return [];
   },
 

toolkit/components/places/nsNavHistoryResult.cpp

@@ -3477,9 +3477,17 @@ nsNavHistoryResult::nsNavHistoryResult(
   MOZ_ASSERT(mRootNode->mIndentLevel == -1,
              "Root node's indent level initialized wrong");
   mRootNode->FillStats();
+
+  AutoTArray<PlacesEventType, 1> events;
+  events.AppendElement(PlacesEventType::Purge_caches);
+  PlacesObservers::AddListener(events, this);
 }
 
 nsNavHistoryResult::~nsNavHistoryResult() {
+  AutoTArray<PlacesEventType, 1> events;
+  events.AppendElement(PlacesEventType::Purge_caches);
+  PlacesObservers::RemoveListener(events, this);
+
   // Delete all heap-allocated bookmark folder observer arrays.
   for (auto it = mBookmarkFolderObservers.Iter(); !it.Done(); it.Next()) {
     delete it.Data();
@@ -4227,6 +4235,10 @@ void nsNavHistoryResult::HandlePlacesEvent(const PlacesEventSequence& aEvents) {
 
         break;
       }
+      case PlacesEventType::Purge_caches: {
+        mRootNode->Refresh();
+        break;
+      }
       default: {
         MOZ_ASSERT_UNREACHABLE(
             "Receive notification of a type not subscribed to.");

tools/lint/eslint/eslint-plugin-mozilla/lib/environments/privileged.js

@@ -432,6 +432,7 @@ module.exports = {
     PlacesEvent: false,
     PlacesHistoryCleared: false,
     PlacesObservers: false,
+    PlacesPurgeCaches: false,
     PlacesRanking: false,
     PlacesVisit: false,
     PlacesVisitRemoved: false,