Merge r164995 - Optimize StylePropertiesSet::findPropertyIndex() to i…

…mprove CSS properties performance https://bugs.webkit.org/show_bug.cgi?id=129605 Patch by Lorenzo Tilve <ltilve@igalia.com> on 2014-03-03 Reviewed by Andreas Kling. Merged from Blink (patch by Mikhail Pozdnyakov): https://src.chromium.org/viewvc/blink?view=revision&revision=167325 Avoid checking whether 'StylePropertiesSet' is mutable and accesing directly to its data members to achieve performance improvements Before the optimization applied: mean: 3064.8337171934063 runs/s median: 3097.5899379343855 runs/s stdev: 66.89274074044187 runs/s min: 2891.7479324362585 runs/s max: 3113.288683440125 runs/s After the optimization applied: mean: 3343.8356114138105 runs/s median: 3356.25682957446 runs/s stdev: 36.297533087489036 runs/s min: 3238.5468032264243 runs/s max: 3368.664837531425 runs/s Performance gain for the average value is approx. 9.1%, in the range of the 10% - 8.2% for the min and max measured values (Linux desktop x64). * css/StyleProperties.cpp: (WebCore::ImmutableStyleProperties::findPropertyIndex): (WebCore::MutableStyleProperties::findPropertyIndex): * css/StyleProperties.h: (WebCore::toMutableStyleProperties): (WebCore::toImmutableStyleProperties): (WebCore::StyleProperties::findPropertyIndex):
WebKit · Mar 6, 2014 · 63bab91 · 63bab91
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diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
@@ -1,3 +1,42 @@
+2014-03-03  Lorenzo Tilve  <ltilve@igalia.com>
+
+        Optimize StylePropertiesSet::findPropertyIndex() to improve CSS properties performance
+        https://bugs.webkit.org/show_bug.cgi?id=129605
+
+        Reviewed by Andreas Kling.
+
+        Merged from Blink (patch by Mikhail Pozdnyakov):
+        https://src.chromium.org/viewvc/blink?view=revision&revision=167325
+
+        Avoid checking whether 'StylePropertiesSet' is mutable and accesing directly to its
+        data members to achieve performance improvements
+
+        Before the optimization applied:
+            mean: 3064.8337171934063 runs/s
+            median: 3097.5899379343855 runs/s
+            stdev: 66.89274074044187 runs/s
+            min: 2891.7479324362585 runs/s
+            max: 3113.288683440125 runs/s
+
+        After the optimization applied:
+            mean: 3343.8356114138105 runs/s
+            median: 3356.25682957446 runs/s
+            stdev: 36.297533087489036 runs/s
+            min: 3238.5468032264243 runs/s
+            max: 3368.664837531425 runs/s
+
+        Performance gain for the average value is approx. 9.1%, in the
+        range of the 10% - 8.2% for the min and max measured
+        values (Linux desktop x64).
+
+        * css/StyleProperties.cpp:
+        (WebCore::ImmutableStyleProperties::findPropertyIndex):
+        (WebCore::MutableStyleProperties::findPropertyIndex):
+        * css/StyleProperties.h:
+        (WebCore::toMutableStyleProperties):
+        (WebCore::toImmutableStyleProperties):
+        (WebCore::StyleProperties::findPropertyIndex):
+
 2014-03-03  Tomas Popela  <tpopela@redhat.com>
 
         [GTK] webkit_dom_range_compare_boundary_points fails when 0 is passed as how parameter

diff --git a/Source/WebCore/css/StyleProperties.cpp b/Source/WebCore/css/StyleProperties.cpp
@@ -1129,15 +1129,29 @@ bool MutableStyleProperties::removePropertiesInSet(const CSSPropertyID* set, uns
     return changed;
 }
 
-int StyleProperties::findPropertyIndex(CSSPropertyID propertyID) const
+int ImmutableStyleProperties::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)
+    for (int n = m_arraySize - 1 ; n >= 0; --n) {
+        if (metadataArray()[n].m_propertyID == id)
             return n;
     }
+
+    return -1;
+}
+
+int MutableStyleProperties::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)
+            return n;
+    }
+
     return -1;
 }
 

diff --git a/Source/WebCore/css/StyleProperties.h b/Source/WebCore/css/StyleProperties.h
@@ -163,6 +163,7 @@ class ImmutableStyleProperties : public StyleProperties {
 
     const CSSValue** valueArray() const;
     const StylePropertyMetadata* metadataArray() const;
+    int findPropertyIndex(CSSPropertyID) const;
 
     void* m_storage;
 
@@ -222,6 +223,8 @@ class MutableStyleProperties : public StyleProperties {
     CSSStyleDeclaration* ensureCSSStyleDeclaration();
     CSSStyleDeclaration* ensureInlineCSSStyleDeclaration(StyledElement* parentElement);
 
+    int findPropertyIndex(CSSPropertyID) const;
+
     Vector<CSSProperty, 4> m_propertyVector;
 
 private:
@@ -236,6 +239,20 @@ class MutableStyleProperties : public StyleProperties {
     friend class StyleProperties;
 };
 
+TYPE_CASTS_BASE(MutableStyleProperties, StyleProperties, set, set->isMutable(), set.isMutable());
+
+inline MutableStyleProperties* toMutableStyleProperties(const RefPtr<StyleProperties>& set)
+{
+    return toMutableStyleProperties(set.get());
+}
+
+TYPE_CASTS_BASE(ImmutableStyleProperties, StyleProperties, set, !set->isMutable(), !set.isMutable());
+
+inline ImmutableStyleProperties* toImmutableStyleProperties(const RefPtr<StyleProperties>& set)
+{
+    return toImmutableStyleProperties(set.get());
+}
+
 inline const StylePropertyMetadata& StyleProperties::PropertyReference::propertyMetadata() const
 {
     if (m_propertySet.isMutable())
@@ -273,6 +290,13 @@ inline void StyleProperties::deref()
         delete static_cast<ImmutableStyleProperties*>(this);
 }
 
+inline int StyleProperties::findPropertyIndex(CSSPropertyID propertyID) const
+{
+    if (m_isMutable)
+        return toMutableStyleProperties(this)->findPropertyIndex(propertyID);
+    return toImmutableStyleProperties(this)->findPropertyIndex(propertyID);
+}
+
 } // namespace WebCore
 
 #endif // StyleProperties_h