StyleResolver should update RuleSets lazily.

Source/core/css/resolver/StyleResolver.cpp

Index: Source/core/css/resolver/StyleResolver.cpp
diff --git a/Source/core/css/resolver/StyleResolver.cpp b/Source/core/css/resolver/StyleResolver.cpp
index 1a745194d5a8089ba4d33fbbf59eaabae0eef019..d78e94e891a5e469245dddcea4ac22d9e4250a0d 100644
--- a/Source/core/css/resolver/StyleResolver.cpp
+++ b/Source/core/css/resolver/StyleResolver.cpp
@@ -57,6 +57,8 @@
 #include "core/css/PageRuleCollector.h"
 #include "core/css/RuleSet.h"
 #include "core/css/StylePropertySet.h"
+#include "core/css/StyleRuleImport.h"
+#include "core/css/StyleSheetContents.h"
 #include "core/css/resolver/AnimatedStyleBuilder.h"
 #include "core/css/resolver/MatchResult.h"
 #include "core/css/resolver/MediaQueryResult.h"
@@ -138,6 +140,7 @@ StyleResolver::StyleResolver(Document& document, bool matchAuthorAndUserStyles)
     , m_matchAuthorAndUserStyles(matchAuthorAndUserStyles)
     , m_fontSelector(CSSFontSelector::create(&document))
     , m_viewportStyleResolver(ViewportStyleResolver::create(&document))
+    , m_needCollectFeatures(false)
     , m_styleResourceLoader(document.fetcher())
 {
     Element* root = document.documentElement();
@@ -181,6 +184,105 @@ StyleResolver::StyleResolver(Document& document, bool matchAuthorAndUserStyles)
     styleSheetCollection->appendActiveAuthorStyleSheets(this);
 }
 
+void StyleResolver::filterFontFaceAndViewportRules(const Vector<RefPtr<StyleRuleBase> >& rules, bool& needsResolveViewport)
+{
+    for (unsigned i = 0; i < rules.size(); ++i) {
+        StyleRuleBase* rule = rules[i].get();
+
+        if (rule->isFontFaceRule()) {
+            const StyleRuleFontFace* fontFaceRule = static_cast<StyleRuleFontFace*>(rule);

[eseidel, 2013/11/06 01:39:10]

Do we have a toStyleRuleFontFace() method instead (which does necessarily
RELEASE_ASSERTs, etc.?)

[tasak, 2013/11/06 05:42:26]

Done.

+            fontSelector()->addFontFaceRule(fontFaceRule);
+            invalidateMatchedPropertiesCache();
+        } else if (rule->isViewportRule()) {
+            m_styleTree.ensureScopedStyleResolver(m_document)->addViewportRule(static_cast<StyleRuleViewport*>(rule));
+            needsResolveViewport = true;
+        } else if (rule->isMediaRule()) {
+            StyleRuleMedia* mediaRule = static_cast<StyleRuleMedia*>(rule);

[eseidel, 2013/11/06 01:39:10]

We've slowly been moving away from using static_cast directly in Blink when
possible and always using toFoo() functions instead since those include ASSERTS
to catch bad casts (before security vulnerabilities happen).

[tasak, 2013/11/06 05:42:26]

Done.

+            if ((!mediaRule->mediaQueries() || m_medium->eval(mediaRule->mediaQueries(), viewportDependentMediaQueryResults())))
+                filterFontFaceAndViewportRules(mediaRule->childRules(), needsResolveViewport);
+        }
+    }
+}
+
+void StyleResolver::filterFontFaceAndViewportRulesFromSheet(StyleSheetContents* sheet, bool& needsResolveViewport)
+{
+    if (!sheet)
+        return;
+
+    if (sheet->importRules().size() > 0) {
+        const Vector<RefPtr<StyleRuleImport> >& importRules = sheet->importRules();
+        for (unsigned i = 0; i < importRules.size(); ++i) {
+            StyleRuleImport* importRule = importRules[i].get();
+            filterFontFaceAndViewportRulesFromSheet(importRule->styleSheet(), needsResolveViewport);
+        }
+    }
+    filterFontFaceAndViewportRules(sheet->childRules(), needsResolveViewport);
+}
+
+bool StyleResolver::filterFontFaceAndViewportRulesFromAuthorStyleSheets(unsigned firstNew, const Vector<RefPtr<CSSStyleSheet> >& styleSheets)
+{
+    bool needsResolveViewport = false;
+
+    unsigned size = styleSheets.size();
+    for (unsigned i = firstNew; i < size; ++i) {
+        CSSStyleSheet* cssSheet = styleSheets[i].get();
+        ASSERT(!cssSheet->disabled());
+        if (cssSheet->mediaQueries() && !m_medium->eval(cssSheet->mediaQueries(), &m_viewportDependentMediaQueryResults))
+            continue;
+        // @viewport and @font-face rules work only in document scope.
+        if (cssSheet->ownerNode()->isInShadowTree() || !isDocumentScope(ScopedStyleResolver::scopingNodeFor(cssSheet)))
+            continue;
+        filterFontFaceAndViewportRulesFromSheet(cssSheet->contents(), needsResolveViewport);
+    }
+    return needsResolveViewport;
+}
+
+void StyleResolver::lazyAppendAuthorStyleSheets(unsigned firstNew, const Vector<RefPtr<CSSStyleSheet> >& styleSheets)
+{
+    // FIXME: Currently We cannot lazy apppend stylesheets if the sheets have @viewport and @font-face rules.
+    // Need to find the best place to update pending stylesheets for "viewport" rules.
+    // Talking about @font-face rules, addFontFaceRule triggers loading font resources.
+    // If we delays "addFontFaceRule", we probably wait more time until fonts are loaded.
+    // At least, we should filter @viewport and @font-face here and should lazily add other rules if possible.
+    bool needsResolveViewport = filterFontFaceAndViewportRulesFromAuthorStyleSheets(firstNew, styleSheets);
+
+    unsigned size = styleSheets.size();
+    for (unsigned i = firstNew; i < size; ++i)
+        m_pendingStyleSheets.add(styleSheets[i].get());
+
+    if (needsResolveViewport)
+        collectViewportRules();
+}
+
+void StyleResolver::removePendingAuthorStyleSheets(const Vector<RefPtr<CSSStyleSheet> >& styleSheets)
+{
+    for (unsigned i = 0; i < styleSheets.size(); ++i)
+        m_pendingStyleSheets.remove(styleSheets[i].get());
+}
+
+void StyleResolver::appendPendingAuthorStyleSheets()
+{
+    setBuildScopedStyleTreeInDocumentOrder(false);
+    for (ListHashSet<CSSStyleSheet*, 16>::iterator it = m_pendingStyleSheets.begin(); it != m_pendingStyleSheets.end(); ++it) {
+        CSSStyleSheet* cssSheet = *it;
+        ASSERT(!cssSheet->disabled());
+        if (cssSheet->mediaQueries() && !m_medium->eval(cssSheet->mediaQueries(), &m_viewportDependentMediaQueryResults))
+            continue;
+
+        StyleSheetContents* sheet = cssSheet->contents();
+        const ContainerNode* scopingNode = ScopedStyleResolver::scopingNodeFor(cssSheet);
+        if (!scopingNode && cssSheet->ownerNode() && cssSheet->ownerNode()->isInShadowTree())
+            continue;
+
+        ScopedStyleResolver* resolver = ensureScopedStyleResolver(scopingNode);
+        ASSERT(resolver);
+        resolver->addRulesFromSheet(sheet, *m_medium, this, false);
+        m_inspectorCSSOMWrappers.collectFromStyleSheetIfNeeded(cssSheet);
+    }
+    m_pendingStyleSheets.clear();
+    finishAppendAuthorStyleSheets();
+}
+
 void StyleResolver::appendAuthorStyleSheets(unsigned firstNew, const Vector<RefPtr<CSSStyleSheet> >& styleSheets)
 {
     // This handles sheets added to the end of the stylesheet list only. In other cases the style resolver
@@ -199,7 +301,7 @@ void StyleResolver::appendAuthorStyleSheets(unsigned firstNew, const Vector<RefP
 
         ScopedStyleResolver* resolver = ensureScopedStyleResolver(scopingNode);
         ASSERT(resolver);
-        resolver->addRulesFromSheet(sheet, *m_medium, this);
+        resolver->addRulesFromSheet(sheet, *m_medium, this, true);
         m_inspectorCSSOMWrappers.collectFromStyleSheetIfNeeded(cssSheet);
     }
 }
@@ -212,6 +314,17 @@ void StyleResolver::finishAppendAuthorStyleSheets()
         document().renderer()->style()->font().update(fontSelector());
 
     collectViewportRules();
+
+    document().styleEngine()->resetCSSFeatureFlags(ruleFeatureSet());
+}
+
+void StyleResolver::resetRuleFeatures()
+{
+    // Need to recreate RuleFeatureSet.
+    m_features.clear();
+    m_siblingRuleSet.clear();
+    m_uncommonAttributeRuleSet.clear();
+    m_needCollectFeatures = true;
 }
 
 void StyleResolver::resetAuthorStyle(const ContainerNode* scopingNode)
@@ -225,6 +338,7 @@ void StyleResolver::resetAuthorStyle(const ContainerNode* scopingNode)
     m_ruleSets.treeBoundaryCrossingRules().reset(scopingNode);
 
     resolver->resetAuthorStyle();
+    resetRuleFeatures();
     if (!scopingNode)
         return;
 
@@ -274,6 +388,7 @@ void StyleResolver::collectFeatures()
 
     m_siblingRuleSet = makeRuleSet(m_features.siblingRules);
     m_uncommonAttributeRuleSet = makeRuleSet(m_features.uncommonAttributeRules);
+    m_needCollectFeatures = false;
 }
 
 bool StyleResolver::hasRulesForId(const AtomicString& id) const
@@ -611,6 +726,8 @@ PassRefPtr<RenderStyle> StyleResolver::styleForElement(Element* element, RenderS
 {
     ASSERT(document().frame());
     ASSERT(documentSettings());
+    ASSERT(!hasPendingAuthorStyleSheets());
+    ASSERT(!m_needCollectFeatures);
 
     // Once an element has a renderer, we don't try to destroy it, since otherwise the renderer
     // will vanish if a style recalc happens during loading.
@@ -707,6 +824,7 @@ PassRefPtr<RenderStyle> StyleResolver::styleForKeyframe(Element* e, const Render
 {
     ASSERT(document().frame());
     ASSERT(documentSettings());
+    ASSERT(!hasPendingAuthorStyleSheets());
 
     if (e == document().documentElement())
         resetDirectionAndWritingModeOnDocument(document());
@@ -782,6 +900,9 @@ void StyleResolver::keyframeStylesForAnimation(Element* e, const RenderStyle* el
     if (!e || list.animationName().isEmpty())
         return;
 
+    if (hasPendingAuthorStyleSheets())
+        appendPendingAuthorStyleSheets();
+
     const StyleRuleKeyframes* keyframesRule = matchScopedKeyframesRule(e, list.animationName().impl());
     if (!keyframesRule)
         return;
@@ -1051,6 +1172,7 @@ PassRefPtr<RenderStyle> StyleResolver::pseudoStyleForElement(Element* e, const P
 
 PassRefPtr<RenderStyle> StyleResolver::styleForPage(int pageIndex)
 {
+    ASSERT(!hasPendingAuthorStyleSheets());
     resetDirectionAndWritingModeOnDocument(document());
     StyleResolverState state(document(), document().documentElement()); // m_rootElementStyle will be set to the document style.