1 files changed, 76 insertions, 0 deletions
diff --git a/dom/storage/StorageNotifierService.h b/dom/storage/StorageNotifierService.h
new file mode 100644
index 0000000000..9568f4b259
--- /dev/null
+++ b/dom/storage/StorageNotifierService.h
@@ -0,0 +1,76 @@
+/* -*- 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_StorageNotifierService_h
+#define mozilla_dom_StorageNotifierService_h
+
+#include "nsISupportsImpl.h"
+#include "nsTObserverArray.h"
+
+class nsIEventTarget;
+class nsIPrincipal;
+class nsPIDOMWindowInner;
+
+namespace mozilla::dom {
+
+class StorageEvent;
+
+/**
+ * Enables the StorageNotifierService to check whether an observer is interested
+ * in receiving events for the given principal before calling the method, an
+ * optimization refactoring.
+ *
+ * Expected to only be implemented by nsGlobalWindowObserver or its succesor.
+ */
+class StorageNotificationObserver {
+ public:
+  NS_INLINE_DECL_PURE_VIRTUAL_REFCOUNTING
+
+  virtual void ObserveStorageNotification(StorageEvent* aEvent,
+                                          const char16_t* aStorageType,
+                                          bool aPrivateBrowsing) = 0;
+
+  virtual bool IsPrivateBrowsing() const = 0;
+
+  virtual nsIPrincipal* GetEffectiveCookiePrincipal() const = 0;
+
+  virtual nsIPrincipal* GetEffectiveStoragePrincipal() const = 0;
+
+  virtual nsIEventTarget* GetEventTarget() const = 0;
+};
+
+/**
+ * A specialized version of the observer service that uses the custom
+ * StorageNotificationObserver so that principal checks can happen in this class
+ * rather than in the nsIObserver::observe method where they used to happen.
+ *
+ * The only expected consumers are nsGlobalWindowInner instances via their
+ * nsGlobalWindowObserver helper that avoids being able to use the window as an
+ * nsIObserver.
+ */
+class StorageNotifierService final {
+ public:
+  NS_INLINE_DECL_REFCOUNTING(StorageNotifierService)
+
+  static StorageNotifierService* GetOrCreate();
+
+  static void Broadcast(StorageEvent* aEvent, const char16_t* aStorageType,
+                        bool aPrivateBrowsing, bool aImmediateDispatch);
+
+  void Register(StorageNotificationObserver* aObserver);
+
+  void Unregister(StorageNotificationObserver* aObserver);
+
+ private:
+  StorageNotifierService();
+  ~StorageNotifierService();
+
+  nsTObserverArray<RefPtr<StorageNotificationObserver>> mObservers;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_StorageNotifierService_h