Changeset 130456 in webkit

Timestamp:

Oct 4, 2012, 9:22:31 PM (13 years ago)

Author:

eric@webkit.org

Message:

SVGAttributeHashTranslator does not need to copy QualifiedName in the common case
​https://bugs.webkit.org/show_bug.cgi?id=98473

Reviewed by Adam Barth.

I tested this using instruments on a test case which modified SVG attributes in a loop.
I believe pdr has some perf-tests in this area, but they weren't needed here. A simple sample showed this as a huge win,
since we're no longer creating a QualifiedName (and thus adding it to the hash) on each QualifiedName-based lookup in SVG.

• svg/SVGElement.h:

(WebCore::SVGAttributeHashTranslator::hash):
(WebCore::SVGAttributeHashTranslator::equal):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• svg/SVGElement.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2012-10-04  Eric Seidel  <eric@webkit.org>
+
+        SVGAttributeHashTranslator does not need to copy QualifiedName in the common case
+        https://bugs.webkit.org/show_bug.cgi?id=98473
+
+        Reviewed by Adam Barth.
+
+        I tested this using instruments on a test case which modified SVG attributes in a loop.
+        I believe pdr has some perf-tests in this area, but they weren't needed here.  A simple sample showed this as a huge win,
+        since we're no longer creating a QualifiedName (and thus adding it to the hash) on each QualifiedName-based lookup in SVG.
+
+        * svg/SVGElement.h:
+        (WebCore::SVGAttributeHashTranslator::hash):
+        (WebCore::SVGAttributeHashTranslator::equal):
+
 2012-10-04  Julien Chaffraix  <jchaffraix@webkit.org>
 

trunk/Source/WebCore/svg/SVGElement.h

@@ -158 +158 @@
 
 struct SVGAttributeHashTranslator {
-    static unsigned hash(QualifiedName key)
+    static unsigned hash(const QualifiedName& key)
     {
-        key.setPrefix(nullAtom);
+        if (key.hasPrefix())
+            return DefaultHash<QualifiedName>::Hash::hash(QualifiedName(nullAtom, key.localName(), key.namespaceURI()));
         return DefaultHash<QualifiedName>::Hash::hash(key);
     }
-    static bool equal(QualifiedName a, QualifiedName b) { return a.matches(b); }
+    static bool equal(const QualifiedName& a, const QualifiedName& b) { return a.matches(b); }
 };