Changeset 139833 in webkit

Timestamp:

Jan 15, 2013 9:23:04 PM (11 years ago)

Author:

rniwa@webkit.org

Message:

NodeRareData doesn't need to have a vtable pointer
​https://bugs.webkit.org/show_bug.cgi?id=106965

Reviewed by Benjamin Poulain.

Made the destructor and reportMemoryUsage of NodeRareDataBase and NodeRareData
respectively and their subclasses non-virtual.

• dom/ElementRareData.cpp:

(SameSizeAsElementRareData): Added.
(WebCore): Added a compile assertion for the size of ElementRareData.

• dom/ElementRareData.h:

(ElementRareData):

• dom/Node.cpp:

(WebCore::Node::clearRareData): Explicitely delete NodeRareData or ElementRareData.
(WebCore::Node::reportMemoryUsage): Explicitely add NodeRareData or ElementRareData.

• dom/Node.h:

(NodeRareDataBase): Deleted the virtual destructor.

• dom/NodeRareData.cpp:

(SameSizeAsNodeRareData): Removed one pointer.

• dom/NodeRareData.h:

(NodeRareData): Removed the virtual destructor.
(NodeRareData::reportMemoryUsage): Made non-virtual.

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• dom/ElementRareData.cpp (modified) (1 diff)
• dom/ElementRareData.h (modified) (4 diffs)
• dom/Node.cpp (modified) (2 diffs)
• dom/Node.h (modified) (1 diff)
• dom/NodeRareData.cpp (modified) (1 diff)
• dom/NodeRareData.h (modified) (2 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-01-15  Ryosuke Niwa  <rniwa@webkit.org>
+
+        NodeRareData doesn't need to have a vtable pointer
+        https://bugs.webkit.org/show_bug.cgi?id=106965
+
+        Reviewed by Benjamin Poulain.
+
+        Made the destructor and reportMemoryUsage of NodeRareDataBase and NodeRareData
+        respectively and their subclasses non-virtual.
+
+        * dom/ElementRareData.cpp:
+        (SameSizeAsElementRareData): Added.
+        (WebCore): Added a compile assertion for the size of ElementRareData.
+        * dom/ElementRareData.h:
+        (ElementRareData):
+        * dom/Node.cpp:
+        (WebCore::Node::clearRareData): Explicitely delete NodeRareData or ElementRareData.
+        (WebCore::Node::reportMemoryUsage): Explicitely add NodeRareData or ElementRareData.
+        * dom/Node.h:
+        (NodeRareDataBase): Deleted the virtual destructor.
+        * dom/NodeRareData.cpp:
+        (SameSizeAsNodeRareData): Removed one pointer.
+        * dom/NodeRareData.h:
+        (NodeRareData): Removed the virtual destructor.
+        (NodeRareData::reportMemoryUsage): Made non-virtual.
+
 2013-01-15  Ian Vollick  <vollick@chromium.org>
 

trunk/Source/WebCore/dom/ElementRareData.cpp

@@ -37 +37 @@
 namespace WebCore {
 
+struct SameSizeAsElementRareData : NodeRareData {
+    short indices[2];
+    unsigned bitfields;
+    LayoutSize sizeForResizing;
+    IntSize scrollOffset;
+    void* pointers[7];
+};
+
+COMPILE_ASSERT(sizeof(ElementRareData) == sizeof(SameSizeAsElementRareData), ElementRareDataShouldStaySmall);
+
 void ElementRareData::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
 {

trunk/Source/WebCore/dom/ElementRareData.h

@@ -37 +37 @@
 public:
     ElementRareData();
-    virtual ~ElementRareData();
+    ~ElementRareData();
 
     void setPseudoElement(PseudoId, PassRefPtr<PseudoElement>);
@@ -95 +95 @@
     void setChildIndex(unsigned index) { m_childIndex = index; }
 
-    virtual void reportMemoryUsage(MemoryObjectInfo*) const OVERRIDE;
+    // Manually called by Node::reportMemoryUsage.
+    void reportMemoryUsage(MemoryObjectInfo*) const;
 
     ElementShadow* shadow() const { return m_shadow.get(); }
@@ -161 +162 @@
 
     LayoutSize m_minimumSizeForResizing;
+    IntSize m_savedLayerScrollOffset;
     RefPtr<RenderStyle> m_computedStyle;
 
@@ -171 +173 @@
     RefPtr<PseudoElement> m_generatedAfter;
 
-    IntSize m_savedLayerScrollOffset;
-
-private:
     void releasePseudoElement(PseudoElement*);
 };

trunk/Source/WebCore/dom/Node.cpp

@@ -472 +472 @@
 
     RenderObject* renderer = m_data.m_rareData->renderer();
-    delete m_data.m_rareData;
+    if (isElementNode())
+        delete static_cast<ElementRareData*>(m_data.m_rareData);
+    else
+        delete m_data.m_rareData;
     m_data.m_renderer = renderer;
     clearFlag(HasRareDataFlag);
@@ -2582 +2585 @@
     info.addMember(m_previous);
     info.addMember(this->renderer());
-    if (hasRareData())
-        info.addMember(rareData());
+    if (hasRareData()) {
+        if (isElementNode())
+            info.addMember(static_cast<ElementRareData*>(rareData()));
+        else
+            info.addMember(rareData());
+    }
 }
 

trunk/Source/WebCore/dom/Node.h

@@ -116 +116 @@
     void setRenderer(RenderObject* renderer) { m_renderer = renderer; }
 
-    virtual ~NodeRareDataBase() { }
 protected:
     NodeRareDataBase() { }
+
 private:
     RenderObject* m_renderer;

trunk/Source/WebCore/dom/NodeRareData.cpp

@@ -40 +40 @@
 
 struct SameSizeAsNodeRareData {
-    void* m_pointer[4];
+    void* m_pointer[3];
 #if ENABLE(MICRODATA)
     void* m_microData;

trunk/Source/WebCore/dom/NodeRareData.h

@@ -281 +281 @@
     { }
 
-    virtual ~NodeRareData()
-    { }
-
     void clearNodeLists() { m_nodeLists.clear(); }
     NodeListsNodeData* nodeLists() const { return m_nodeLists.get(); }
@@ -310 +307 @@
 #endif
 
-    virtual void reportMemoryUsage(MemoryObjectInfo*) const;
+    // This member function is intentionially not virtual to avoid adding a vtable pointer.
+    void reportMemoryUsage(MemoryObjectInfo*) const;
 
 private: