Bug 1377993 - Make node slots less memory hungry in common cases.

Tag UXP Issue #1344

2 files changed, 12 insertions, 57 deletions

diff --git a/dom/xul/nsXULElement.cpp b/dom/xul/nsXULElement.cpp
index e351a46eb..a854f53ec 100644
--- a/dom/xul/nsXULElement.cpp
+++ b/dom/xul/nsXULElement.cpp
@@ -174,33 +174,6 @@ nsXULElement::~nsXULElement()
 {
 }
 
-nsXULElement::nsXULSlots::nsXULSlots()
-    : nsXULElement::nsDOMSlots()
-{
-}
-
-nsXULElement::nsXULSlots::~nsXULSlots()
-{
-    NS_IF_RELEASE(mControllers); // Forces release
-    nsCOMPtr<nsIFrameLoader> frameLoader = do_QueryInterface(mFrameLoaderOrOpener);
-    if (frameLoader) {
-        static_cast<nsFrameLoader*>(frameLoader.get())->Destroy();
-    }
-}
-
-void
-nsXULElement::nsXULSlots::Traverse(nsCycleCollectionTraversalCallback &cb)
-{
-    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mSlots->mFrameLoaderOrOpener");
-    cb.NoteXPCOMChild(mFrameLoaderOrOpener);
-}
-
-nsINode::nsSlots*
-nsXULElement::CreateSlots()
-{
-    return new nsXULSlots();
-}
-
 void
 nsXULElement::MaybeUpdatePrivateLifetime()
 {
@@ -326,12 +299,7 @@ NS_IMPL_CYCLE_COLLECTION_CLASS(nsXULElement)
 
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(nsXULElement,
                                                   nsStyledElement)
-    {
-        nsXULSlots* slots = static_cast<nsXULSlots*>(tmp->GetExistingSlots());
-        if (slots) {
-            slots->Traverse(cb);
-        }
-    }
+
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(nsXULElement,
@@ -895,9 +863,9 @@ nsXULElement::UnbindFromTree(bool aDeep, bool aNullParent)
     // mDocument in nsGlobalWindow::SetDocShell, but I'm not
     // sure whether that would fix all possible cycles through
     // mControllers.)
-    nsXULSlots* slots = static_cast<nsXULSlots*>(GetExistingDOMSlots());
+    nsExtendedDOMSlots* slots = GetExistingExtendedDOMSlots();
     if (slots) {
-        NS_IF_RELEASE(slots->mControllers);
+        slots->mControllers = nullptr;
         RefPtr<nsFrameLoader> frameLoader = GetFrameLoader();
         if (frameLoader) {
             frameLoader->Destroy();
@@ -1241,9 +1209,9 @@ nsXULElement::RemoveBroadcaster(const nsAString & broadcasterId)
 void
 nsXULElement::DestroyContent()
 {
-    nsXULSlots* slots = static_cast<nsXULSlots*>(GetExistingDOMSlots());
+    nsExtendedDOMSlots* slots = GetExistingExtendedDOMSlots();
     if (slots) {
-        NS_IF_RELEASE(slots->mControllers);
+        slots->mControllers = nullptr;
         RefPtr<nsFrameLoader> frameLoader = GetFrameLoader();
         if (frameLoader) {
             frameLoader->Destroy();
@@ -1473,7 +1441,7 @@ nsIControllers*
 nsXULElement::GetControllers(ErrorResult& rv)
 {
     if (! Controllers()) {
-        nsDOMSlots* slots = DOMSlots();
+        nsExtendedDOMSlots* slots = ExtendedDOMSlots();
 
         rv = NS_NewXULControllers(nullptr, NS_GET_IID(nsIControllers),
                                   reinterpret_cast<void**>(&slots->mControllers));
@@ -1578,7 +1546,7 @@ nsXULElement::LoadSrc()
     RefPtr<nsFrameLoader> frameLoader = GetFrameLoader();
     if (!frameLoader) {
         // Check if we have an opener we need to be setting
-        nsXULSlots* slots = static_cast<nsXULSlots*>(Slots());
+        nsExtendedDOMSlots* slots = ExtendedDOMSlots();
         nsCOMPtr<nsPIDOMWindowOuter> opener = do_QueryInterface(slots->mFrameLoaderOrOpener);
         if (!opener) {
             // If we are a content-primary xul-browser, we want to take the opener property!
@@ -1624,7 +1592,7 @@ nsXULElement::GetFrameLoaderXPCOM(nsIFrameLoader **aFrameLoader)
 already_AddRefed<nsFrameLoader>
 nsXULElement::GetFrameLoader()
 {
-    nsXULSlots* slots = static_cast<nsXULSlots*>(GetExistingSlots());
+    nsExtendedDOMSlots* slots = GetExistingExtendedDOMSlots();
     if (!slots)
         return nullptr;
 
@@ -1646,7 +1614,7 @@ nsXULElement::GetParentApplication(mozIApplication** aApplication)
 void
 nsXULElement::PresetOpenerWindow(mozIDOMWindowProxy* aWindow, ErrorResult& aRv)
 {
-    nsXULSlots* slots = static_cast<nsXULSlots*>(Slots());
+    nsExtendedDOMSlots* slots = ExtendedDOMSlots();
     MOZ_ASSERT(!slots->mFrameLoaderOrOpener, "A frameLoader or opener is present when calling PresetOpenerWindow");
 
     slots->mFrameLoaderOrOpener = aWindow;
@@ -1662,7 +1630,7 @@ nsXULElement::SetIsPrerendered()
 void
 nsXULElement::InternalSetFrameLoader(nsIFrameLoader* aNewFrameLoader)
 {
-    nsXULSlots* slots = static_cast<nsXULSlots*>(GetExistingDOMSlots());
+    nsExtendedDOMSlots* slots = GetExistingExtendedDOMSlots();
     MOZ_ASSERT(slots);
 
     slots->mFrameLoaderOrOpener = aNewFrameLoader;
diff --git a/dom/xul/nsXULElement.h b/dom/xul/nsXULElement.h
index 164afacd3..80424412f 100644
--- a/dom/xul/nsXULElement.h
+++ b/dom/xul/nsXULElement.h
@@ -609,19 +609,6 @@ protected:
 
     nsresult AddPopupListener(nsIAtom* aName);
 
-    class nsXULSlots : public mozilla::dom::Element::nsDOMSlots
-    {
-    public:
-        nsXULSlots();
-        virtual ~nsXULSlots();
-
-        void Traverse(nsCycleCollectionTraversalCallback &cb);
-
-        nsCOMPtr<nsISupports> mFrameLoaderOrOpener;
-    };
-
-    virtual nsINode::nsSlots* CreateSlots() override;
-
     nsresult LoadSrc();
 
     /**
@@ -677,8 +664,8 @@ protected:
     // Internal accessor. This shadows the 'Slots', and returns
     // appropriate value.
     nsIControllers *Controllers() {
-      nsDOMSlots* slots = GetExistingDOMSlots();
-      return slots ? slots->mControllers : nullptr;
+      nsExtendedDOMSlots* slots = GetExistingExtendedDOMSlots();
+      return slots ? slots->mControllers.get() : nullptr;
     }
 
     void UnregisterAccessKey(const nsAString& aOldValue);