WontFix: Add fast path for id/name/style/class in getAttribute/setAttribute bindings.

Source/core/dom/Element.cpp

Index: Source/core/dom/Element.cpp
diff --git a/Source/core/dom/Element.cpp b/Source/core/dom/Element.cpp
index bb3e0aad6f5ef42a05593dfba29040649ea60d5c..aa505909a6712eca6a0035acc1871195197c7620 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -908,6 +908,41 @@ IntRect Element::screenRect() const
     return document().view()->contentsToScreen(renderer()->absoluteBoundingBoxRectIgnoringTransforms());
 }
 
+static inline const QualifiedName& fastAttributeNameFromString(const String& localName)

[Inactive, 2014/03/10 19:56:23]

add "const Element& element" argument.

+{
+    unsigned length = localName.length();
+    if (!length)
+        return nullQName();
+    const StringImpl& name = *localName.impl();
+
+    if (length == 2 && name[0] == 'i' && name[1] == 'd')
+        return HTMLNames::idAttr;
+    if (length == 4 && name[0] == 'n' && name[1] == 'a' && name[2] == 'm' && name[3] == 'e')
+        return HTMLNames::nameAttr;
+    if (length == 5 && name[0] == 'c' && name[1] == 'l' && name[2] == 'a' && name[3] == 's' && name[4] == 's')

[Inactive, 2014/03/10 19:56:23]

add "!element.isSVGElement() && " condition.

+        return HTMLNames::classAttr;

[Inactive, 2014/03/10 18:58:26]

Technically, I believe we cannot do a fast lookup for the "class" attribute for
SVG elements either, because it is animated:
Source/core/svg/SVGElement.idl:    [MeasureAs=SVGClassName] readonly attribute
SVGAnimatedString className;

I believe you are likely breaking getAttribute("class") on SVG elements.

+
+    return nullQName();
+}
+
+const AtomicString& Element::bindingsGetAttribute(const String& localName) const
+{
+    const QualifiedName& fastName = fastAttributeNameFromString(localName);

[Inactive, 2014/03/10 19:56:23]

fastAttributeNameFromString(*this, localName);

+    if (fastName != nullQName())
+        return fastGetAttribute(fastName);
+    return getAttribute(AtomicString(localName));
+}
+
+void Element::bindingsSetAttribute(const String& localName, const String& newValue, ExceptionState& exceptionState)

[Inactive, 2014/03/10 18:46:45]

I think I made this comment before but newValue should really be an const
AtomicString& here, not a const String& as we always use it as an AtomicString.
It makes little sense for the bindings to construct a String if it will anyway
be converted into an AtomicString internally.

[Inactive, 2014/03/10 20:04:15]

To be clear, I only want newValue to be an AtomicString. Keeping localName as a
String is fine. Unlike WebKit, our AtomicString(const String&) constructor is
explicit so it is more obvious when we are converting a String to an
AtomicString.

+{
+    const QualifiedName& fastName = fastAttributeNameFromString(localName);

[Inactive, 2014/03/10 19:56:23]

fastAttributeNameFromString(*this, localName);

+    if (fastName != nullQName()) {
+        setAttribute(fastName, AtomicString(newValue));
+        return;
+    }
+    setAttribute(AtomicString(localName), AtomicString(newValue), exceptionState);
+}
+
 const AtomicString& Element::getAttribute(const AtomicString& localName) const
 {
     if (!elementData())