Optimize StylePropertySet::findPropertyIndex() to improve CSS properties performance

Source/core/css/StylePropertySet.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Research In Motion Limited. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 76 matching lines @@
     }
 }
 
 ImmutableStylePropertySet::~ImmutableStylePropertySet()
 {
     CSSValue** valueArray = const_cast<CSSValue**>(this->valueArray());
     for (unsigned i = 0; i < m_arraySize; ++i)
         valueArray[i]->deref();
 }
 
+int ImmutableStylePropertySet::findPropertyIndex(CSSPropertyID propertyID) const
+{
+    // Convert here propertyID into an uint16_t to compare it with the metadata's m_propertyID to avoid
+    // the compiler converting it to an int multiple times in the loop.
+    uint16_t id = static_cast<uint16_t>(propertyID);
+    for (int n = m_arraySize - 1 ; n >= 0; --n) {
+        if (metadataArray()[n].m_propertyID == id) {
+            // Only enabled or internal properties should be part of the style.
+            ASSERT(RuntimeCSSEnabled::isCSSPropertyEnabled(propertyID) || isInternalProperty(propertyID));
+            return n;
+        }
+    }
+
+    return -1;
+}
+
 MutableStylePropertySet::MutableStylePropertySet(const StylePropertySet& other)
     : StylePropertySet(other.cssParserMode())
 {
     if (other.isMutable()) {
         m_propertyVector = toMutableStylePropertySet(other).m_propertyVector;
     } else {
         m_propertyVector.reserveInitialCapacity(other.propertyCount());
         for (unsigned i = 0; i < other.propertyCount(); ++i)
             m_propertyVector.uncheckedAppend(other.propertyAt(i).toCSSProperty());
     }
@@ skipping 308 matching lines @@
                 continue;
         }
         newProperties.append(property);
     }
 
     bool changed = newProperties.size() != m_propertyVector.size();
     m_propertyVector = newProperties;
     return changed;
 }
 
-int StylePropertySet::findPropertyIndex(CSSPropertyID propertyID) const
-{
-    // Convert here propertyID into an uint16_t to compare it with the metadata's m_propertyID to avoid
-    // the compiler converting it to an int multiple times in the loop.
-    uint16_t id = static_cast<uint16_t>(propertyID);
-    for (int n = propertyCount() - 1 ; n >= 0; --n) {
-        if (id == propertyAt(n).propertyMetadata().m_propertyID) {
-            // Only enabled or internal properties should be part of the style.
-            ASSERT(RuntimeCSSEnabled::isCSSPropertyEnabled(propertyID) || isInternalProperty(propertyID));
-            return n;
-        }
-    }
-    return -1;
-}
-
 CSSProperty* MutableStylePropertySet::findCSSPropertyWithID(CSSPropertyID propertyID)
 {
     int foundPropertyIndex = findPropertyIndex(propertyID);
     if (foundPropertyIndex == -1)
         return 0;
     return &m_propertyVector.at(foundPropertyIndex);
 }
 
 bool StylePropertySet::propertyMatches(CSSPropertyID propertyID, const CSSValue* propertyValue) const
 {
@@ skipping 54 matching lines @@
     // style property set.
     if (m_cssomWrapper) {
         ASSERT(!static_cast<CSSStyleDeclaration*>(m_cssomWrapper.get())->parentRule());
         ASSERT(!m_cssomWrapper->parentElement());
         return m_cssomWrapper.get();
     }
     m_cssomWrapper = adoptPtr(new PropertySetCSSStyleDeclaration(this));
     return m_cssomWrapper.get();
 }
 
+int MutableStylePropertySet::findPropertyIndex(CSSPropertyID propertyID) const
+{
+    // Convert here propertyID into an uint16_t to compare it with the metadata's m_propertyID to avoid
+    // the compiler converting it to an int multiple times in the loop.
+    uint16_t id = static_cast<uint16_t>(propertyID);
+    for (int n = m_propertyVector.size() - 1 ; n >= 0; --n) {
+        if (m_propertyVector.at(n).metadata().m_propertyID == id) {
+            // Only enabled or internal properties should be part of the style.
+            ASSERT(RuntimeCSSEnabled::isCSSPropertyEnabled(propertyID) || isInternalProperty(propertyID));
+            return n;
+        }
+    }
+
+    return -1;
+}
+
 unsigned StylePropertySet::averageSizeInBytes()
 {
     // Please update this if the storage scheme changes so that this longer reflects the actual size.
     return sizeForImmutableStylePropertySetWithPropertyCount(4);
 }
 
 // See the function above if you need to update this.
 struct SameSizeAsStylePropertySet : public RefCounted<SameSizeAsStylePropertySet> {
     unsigned bitfield;
 };
@@ skipping 28 matching lines @@
     result.appendLiteral(": ");
     result.append(propertyValue()->cssText());
     if (isImportant())
         result.appendLiteral(" !important");
     result.append(';');
     return result.toString();
 }
 
 
 } // namespace WebCore