/* -*- 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_localstorage_LSObject_h #define mozilla_dom_localstorage_LSObject_h #include "mozilla/dom/Storage.h" class nsGlobalWindowInner; class nsIPrincipal; class nsPIDOMWindowInner; namespace mozilla { class ErrorResult; namespace ipc { class PrincipalInfo; } // namespace ipc namespace dom { class LSDatabase; class LSObjectChild; class LSObserver; class LSRequestChild; class LSRequestChildCallback; class LSRequestParams; class LSRequestResponse; /** * Backs the WebIDL `Storage` binding; all content LocalStorage calls are * handled by this class. * * ## Semantics under e10s / multi-process ## * * A snapshot mechanism used in conjuction with stable points ensures that JS * run-to-completion semantics are experienced even if the same origin is * concurrently accessing LocalStorage across multiple content processes. * * ### Snapshot Consistency ### * * An LSSnapshot is created locally whenever the contents of LocalStorage are * about to be read or written (including length). This synchronously * establishes a corresponding Snapshot in PBackground in the parent process. * An effort is made to send as much data from the parent process as possible, * so sites using a small/reasonable amount of LocalStorage data will have it * sent to the content process for immediate access. Sites with greater * LocalStorage usage may only have some of the information relayed. In that * case, the parent Snapshot will ensure that it retains the exact state of the * parent Datastore at the moment the Snapshot was created. */ class LSObject final : public Storage { typedef mozilla::ipc::PrincipalInfo PrincipalInfo; friend nsGlobalWindowInner; nsAutoPtr mPrincipalInfo; RefPtr mDatabase; RefPtr mObserver; uint32_t mPrivateBrowsingId; nsCString mOrigin; nsString mDocumentURI; bool mInExplicitSnapshot; public: /** * The normal creation path invoked by nsGlobalWindowInner. */ static nsresult CreateForWindow(nsPIDOMWindowInner* aWindow, Storage** aStorage); /** * nsIDOMStorageManager creation path for use in testing logic. Supports the * system principal where CreateForWindow does not. This is also why aPrivate * exists separate from the principal; because the system principal can never * be mutated to have a private browsing id even though it can be used in a * window/document marked as private browsing. That's a legacy issue that is * being dealt with, but it's why it exists here. */ static nsresult CreateForPrincipal(nsPIDOMWindowInner* aWindow, nsIPrincipal* aPrincipal, const nsAString& aDocumentURI, bool aPrivate, LSObject** aObject); /** * Used for requests from the parent process to the parent process; in that * case we want ActorsParent to know our event-target and this is better than * trying to tunnel the pointer through IPC. */ static already_AddRefed GetSyncLoopEventTarget(); /** * Helper invoked by ContentChild::OnChannelReceivedMessage when a sync IPC * message is received. This will be invoked on the IPC I/O thread and it * will set the gPendingSyncMessage flag to true. It will also force the sync * loop (if it's active) to check the gPendingSyncMessage flag which will * result in premature finish of the loop. * * This is necessary to unblock the main thread when a sync IPC message is * received to avoid the potential for browser deadlock. This should only * occur in (ugly) testing scenarios where CPOWs are in use. * * Aborted sync loop will result in the underlying LSRequest being explicitly * canceled, resulting in the parent sending an NS_ERROR_FAILURE result. */ static void OnSyncMessageReceived(); /* * Helper invoked by ContentChild::OnMessageReceived when a sync IPC message * has been handled. This will be invoked on the main thread and it will * set the gPendingSyncMessage flag to false. */ static void OnSyncMessageHandled(); void AssertIsOnOwningThread() const { NS_ASSERT_OWNINGTHREAD(LSObject); } const nsString& DocumentURI() const { return mDocumentURI; } LSRequestChild* StartRequest(nsIEventTarget* aMainEventTarget, const LSRequestParams& aParams, LSRequestChildCallback* aCallback); // Storage overrides. StorageType Type() const override; bool IsForkOf(const Storage* aStorage) const override; int64_t GetOriginQuotaUsage() const override; uint32_t GetLength(nsIPrincipal& aSubjectPrincipal, ErrorResult& aError) override; void Key(uint32_t aIndex, nsAString& aResult, nsIPrincipal& aSubjectPrincipal, ErrorResult& aError) override; void GetItem(const nsAString& aKey, nsAString& aResult, nsIPrincipal& aSubjectPrincipal, ErrorResult& aError) override; void GetSupportedNames(nsTArray& aNames) override; void SetItem(const nsAString& aKey, const nsAString& aValue, nsIPrincipal& aSubjectPrincipal, ErrorResult& aError) override; void RemoveItem(const nsAString& aKey, nsIPrincipal& aSubjectPrincipal, ErrorResult& aError) override; void Clear(nsIPrincipal& aSubjectPrincipal, ErrorResult& aError) override; ////////////////////////////////////////////////////////////////////////////// // Testing Methods: See Storage.h void Open(nsIPrincipal& aSubjectPrincipal, ErrorResult& aError) override; void Close(nsIPrincipal& aSubjectPrincipal, ErrorResult& aError) override; void BeginExplicitSnapshot(nsIPrincipal& aSubjectPrincipal, ErrorResult& aError) override; void EndExplicitSnapshot(nsIPrincipal& aSubjectPrincipal, ErrorResult& aError) override; ////////////////////////////////////////////////////////////////////////////// NS_DECL_ISUPPORTS_INHERITED NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(LSObject, Storage) private: LSObject(nsPIDOMWindowInner* aWindow, nsIPrincipal* aPrincipal); ~LSObject(); nsresult DoRequestSynchronously(const LSRequestParams& aParams, LSRequestResponse& aResponse); nsresult EnsureDatabase(); void DropDatabase(); /** * Invoked by nsGlobalWindowInner whenever a new "storage" event listener is * added to the window in order to ensure that "storage" events are received * from other processes. (`LSObject::OnChange` directly invokes * `Storage::NotifyChange` to notify in-process listeners.) * * If this is the first request in the process for an observer for this * origin, this will trigger a RequestHelper-mediated synchronous LSRequest * to prepare a new observer in the parent process and also construction of * corresponding actors, which will result in the observer being fully * registered in the parent process. */ nsresult EnsureObserver(); /** * Invoked by nsGlobalWindowInner whenever its last "storage" event listener * is removed. */ void DropObserver(); /** * Internal helper method used by mutation methods that wraps the call to * Storage::NotifyChange to generate same-process "storage" events. */ void OnChange(const nsAString& aKey, const nsAString& aOldValue, const nsAString& aNewValue); nsresult EndExplicitSnapshotInternal(); // Storage overrides. void LastRelease() override; }; } // namespace dom } // namespace mozilla #endif // mozilla_dom_localstorage_LSObject_h