path: root/Source/WebCore/css/RuleSet.cpp

/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
 * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
 * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
 * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
 * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
 * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
 * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
 * Copyright (C) Research In Motion Limited 2011. All rights reserved.
 * Copyright (C) 2012 Google Inc. 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.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "config.h"
#include "RuleSet.h"

#include "CSSFontSelector.h"
#include "CSSSelector.h"
#include "CSSSelectorList.h"
#include "HTMLNames.h"
#include "MediaQueryEvaluator.h"
#include "SecurityOrigin.h"
#include "SelectorChecker.h"
#include "StyleResolver.h"
#include "StyleRule.h"
#include "StyleRuleImport.h"
#include "StyleSheetContents.h"
#include "WebCoreMemoryInstrumentation.h"
#include "WebKitCSSKeyframesRule.h"
#include <wtf/MemoryInstrumentationHashMap.h>
#include <wtf/MemoryInstrumentationHashSet.h>
#include <wtf/MemoryInstrumentationVector.h>

namespace WebCore {

using namespace HTMLNames;

// -----------------------------------------------------------------

static inline bool isSelectorMatchingHTMLBasedOnRuleHash(const CSSSelector* selector)
{
    const AtomicString& selectorNamespace = selector->tag().namespaceURI();
    if (selectorNamespace != starAtom && selectorNamespace != xhtmlNamespaceURI)
        return false;
    if (selector->m_match == CSSSelector::None)
        return true;
    if (selector->tag() != starAtom)
        return false;
    if (SelectorChecker::isCommonPseudoClassSelector(selector))
        return true;
    return selector->m_match == CSSSelector::Id || selector->m_match == CSSSelector::Class;
}

static inline bool selectorListContainsUncommonAttributeSelector(const CSSSelector* selector)
{
    CSSSelectorList* selectorList = selector->selectorList();
    if (!selectorList)
        return false;
    for (CSSSelector* subSelector = selectorList->first(); subSelector; subSelector = CSSSelectorList::next(subSelector)) {
        if (subSelector->isAttributeSelector())
            return true;
    }
    return false;
}

static inline bool isCommonAttributeSelectorAttribute(const QualifiedName& attribute)
{
    // These are explicitly tested for equality in canShareStyleWithElement.
    return attribute == typeAttr || attribute == readonlyAttr;
}

static inline bool containsUncommonAttributeSelector(const CSSSelector* selector)
{
    for (; selector; selector = selector->tagHistory()) {
        // Allow certain common attributes (used in the default style) in the selectors that match the current element.
        if (selector->isAttributeSelector() && !isCommonAttributeSelectorAttribute(selector->attribute()))
            return true;
        if (selectorListContainsUncommonAttributeSelector(selector))
            return true;
        if (selector->relation() != CSSSelector::SubSelector) {
            selector = selector->tagHistory();
            break;
        }
    }

    for (; selector; selector = selector->tagHistory()) {
        if (selector->isAttributeSelector())
            return true;
        if (selectorListContainsUncommonAttributeSelector(selector))
            return true;
    }
    return false;
}

RuleData::RuleData(StyleRule* rule, unsigned selectorIndex, unsigned position, bool hasDocumentSecurityOrigin, bool canUseFastCheckSelector, bool inRegionRule)
    : m_rule(rule)
    , m_selectorIndex(selectorIndex)
    , m_position(position)
    , m_specificity(selector()->specificity())
    , m_hasFastCheckableSelector(canUseFastCheckSelector && SelectorChecker::isFastCheckableSelector(selector()))
    , m_hasMultipartSelector(!!selector()->tagHistory())
    , m_hasRightmostSelectorMatchingHTMLBasedOnRuleHash(isSelectorMatchingHTMLBasedOnRuleHash(selector()))
    , m_containsUncommonAttributeSelector(WebCore::containsUncommonAttributeSelector(selector()))
    , m_linkMatchType(SelectorChecker::determineLinkMatchType(selector()))
    , m_hasDocumentSecurityOrigin(hasDocumentSecurityOrigin)
    , m_isInRegionRule(inRegionRule)
{
    ASSERT(m_position == position);
    ASSERT(m_selectorIndex == selectorIndex);
    SelectorChecker::collectIdentifierHashes(selector(), m_descendantSelectorIdentifierHashes, maximumIdentifierCount);
}

void RuleData::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
{
    MemoryClassInfo info(memoryObjectInfo, this, WebCoreMemoryTypes::CSS);
}

static void reportAtomRuleMap(MemoryClassInfo* info, const RuleSet::AtomRuleMap& atomicRuleMap)
{
    info->addMember(atomicRuleMap);
    for (RuleSet::AtomRuleMap::const_iterator it = atomicRuleMap.begin(); it != atomicRuleMap.end(); ++it)
        info->addMember(*it->value);
}

void RuleSet::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
{
    MemoryClassInfo info(memoryObjectInfo, this, WebCoreMemoryTypes::CSS);
    reportAtomRuleMap(&info, m_idRules);
    reportAtomRuleMap(&info, m_classRules);
    reportAtomRuleMap(&info, m_tagRules);
    reportAtomRuleMap(&info, m_shadowPseudoElementRules);
    info.addMember(m_linkPseudoClassRules);
    info.addMember(m_focusPseudoClassRules);
    info.addMember(m_universalRules);
    info.addMember(m_pageRules);
    info.addMember(m_regionSelectorsAndRuleSets);
}

void RuleSet::RuleSetSelectorPair::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
{
    MemoryClassInfo info(memoryObjectInfo, this, WebCoreMemoryTypes::CSS);
    info.addMember(ruleSet);
}

static inline void collectFeaturesFromSelector(RuleFeatureSet& features, const CSSSelector* selector)
{
    if (selector->m_match == CSSSelector::Id)
        features.idsInRules.add(selector->value().impl());
    if (selector->isAttributeSelector())
        features.attrsInRules.add(selector->attribute().localName().impl());
    switch (selector->pseudoType()) {
    case CSSSelector::PseudoFirstLine:
        features.usesFirstLineRules = true;
        break;
    case CSSSelector::PseudoBefore:
    case CSSSelector::PseudoAfter:
        features.usesBeforeAfterRules = true;
        break;
    default:
        break;
    }
}

static void collectFeaturesFromRuleData(RuleFeatureSet& features, const RuleData& ruleData)
{
    bool foundSiblingSelector = false;
    for (CSSSelector* selector = ruleData.selector(); selector; selector = selector->tagHistory()) {
        collectFeaturesFromSelector(features, selector);
        
        if (CSSSelectorList* selectorList = selector->selectorList()) {
            for (CSSSelector* subSelector = selectorList->first(); subSelector; subSelector = CSSSelectorList::next(subSelector)) {
                if (!foundSiblingSelector && selector->isSiblingSelector())
                    foundSiblingSelector = true;
                collectFeaturesFromSelector(features, subSelector);
            }
        } else if (!foundSiblingSelector && selector->isSiblingSelector())
            foundSiblingSelector = true;
    }
    if (foundSiblingSelector)
        features.siblingRules.append(RuleFeature(ruleData.rule(), ruleData.selectorIndex(), ruleData.hasDocumentSecurityOrigin()));
    if (ruleData.containsUncommonAttributeSelector())
        features.uncommonAttributeRules.append(RuleFeature(ruleData.rule(), ruleData.selectorIndex(), ruleData.hasDocumentSecurityOrigin()));
}
    
void RuleSet::addToRuleSet(AtomicStringImpl* key, AtomRuleMap& map, const RuleData& ruleData)
{
    if (!key)
        return;
    OwnPtr<Vector<RuleData> >& rules = map.add(key, nullptr).iterator->value;
    if (!rules)
        rules = adoptPtr(new Vector<RuleData>);
    rules->append(ruleData);
}

void RuleSet::addRule(StyleRule* rule, unsigned selectorIndex, bool hasDocumentSecurityOrigin, bool canUseFastCheckSelector, bool inRegionRule)
{
    RuleData ruleData(rule, selectorIndex, m_ruleCount++, hasDocumentSecurityOrigin, canUseFastCheckSelector, inRegionRule);
    collectFeaturesFromRuleData(m_features, ruleData);

    CSSSelector* selector = ruleData.selector();

    if (selector->m_match == CSSSelector::Id) {
        addToRuleSet(selector->value().impl(), m_idRules, ruleData);
        return;
    }
    if (selector->m_match == CSSSelector::Class) {
        addToRuleSet(selector->value().impl(), m_classRules, ruleData);
        return;
    }
    if (selector->isUnknownPseudoElement()) {
        addToRuleSet(selector->value().impl(), m_shadowPseudoElementRules, ruleData);
        return;
    }
    if (SelectorChecker::isCommonPseudoClassSelector(selector)) {
        switch (selector->pseudoType()) {
        case CSSSelector::PseudoLink:
        case CSSSelector::PseudoVisited:
        case CSSSelector::PseudoAnyLink:
            m_linkPseudoClassRules.append(ruleData);
            return;
        case CSSSelector::PseudoFocus:
            m_focusPseudoClassRules.append(ruleData);
            return;
        default:
            ASSERT_NOT_REACHED();
        }
        return;
    }
    const AtomicString& localName = selector->tag().localName();
    if (localName != starAtom) {
        addToRuleSet(localName.impl(), m_tagRules, ruleData);
        return;
    }
    m_universalRules.append(ruleData);
}

void RuleSet::addPageRule(StyleRulePage* rule)
{
    m_pageRules.append(rule);
}

void RuleSet::addRegionRule(StyleRuleRegion* regionRule, bool hasDocumentSecurityOrigin)
{
    OwnPtr<RuleSet> regionRuleSet = RuleSet::create();
    // The region rule set should take into account the position inside the parent rule set.
    // Otherwise, the rules inside region block might be incorrectly positioned before other similar rules from
    // the stylesheet that contains the region block.
    regionRuleSet->m_ruleCount = m_ruleCount;

    // Collect the region rules into a rule set
    const Vector<RefPtr<StyleRuleBase> >& childRules = regionRule->childRules();
    for (unsigned i = 0; i < childRules.size(); ++i) {
        StyleRuleBase* regionStylingRule = childRules[i].get();
        if (regionStylingRule->isStyleRule())
            regionRuleSet->addStyleRule(static_cast<StyleRule*>(regionStylingRule), hasDocumentSecurityOrigin, true, true);
    }
    // Update the "global" rule count so that proper order is maintained
    m_ruleCount = regionRuleSet->m_ruleCount;

    m_regionSelectorsAndRuleSets.append(RuleSetSelectorPair(regionRule->selectorList().first(), regionRuleSet.release()));
}

void RuleSet::addRulesFromSheet(StyleSheetContents* sheet, const MediaQueryEvaluator& medium, StyleResolver* resolver, const ContainerNode* scope)
{
    ASSERT(sheet);
    
    const Vector<RefPtr<StyleRuleImport> >& importRules = sheet->importRules();
    for (unsigned i = 0; i < importRules.size(); ++i) {
        StyleRuleImport* importRule = importRules[i].get();
        if (importRule->styleSheet() && (!importRule->mediaQueries() || medium.eval(importRule->mediaQueries(), resolver)))
            addRulesFromSheet(importRule->styleSheet(), medium, resolver, scope);
    }
    bool hasDocumentSecurityOrigin = resolver && resolver->document()->securityOrigin()->canRequest(sheet->baseURL());

    const Vector<RefPtr<StyleRuleBase> >& rules = sheet->childRules();
    for (unsigned i = 0; i < rules.size(); ++i) {
        StyleRuleBase* rule = rules[i].get();

        ASSERT(!rule->isImportRule());
        if (rule->isStyleRule())
            addStyleRule(static_cast<StyleRule*>(rule), hasDocumentSecurityOrigin, !scope);
        else if (rule->isPageRule())
            addPageRule(static_cast<StyleRulePage*>(rule));
        else if (rule->isMediaRule()) {
            StyleRuleMedia* mediaRule = static_cast<StyleRuleMedia*>(rule);

            if ((!mediaRule->mediaQueries() || medium.eval(mediaRule->mediaQueries(), resolver))) {
                // Traverse child elements of the @media rule.
                const Vector<RefPtr<StyleRuleBase> >& childRules = mediaRule->childRules();
                for (unsigned j = 0; j < childRules.size(); ++j) {
                    StyleRuleBase* childRule = childRules[j].get();
                    if (childRule->isStyleRule())
                        addStyleRule(static_cast<StyleRule*>(childRule), hasDocumentSecurityOrigin, !scope);
                    else if (childRule->isPageRule())
                        addPageRule(static_cast<StyleRulePage*>(childRule));
                    else if (childRule->isFontFaceRule() && resolver) {
                        // Add this font face to our set.
                        // FIXME(BUG 72461): We don't add @font-face rules of scoped style sheets for the moment.
                        if (scope)
                            continue;
                        const StyleRuleFontFace* fontFaceRule = static_cast<StyleRuleFontFace*>(childRule);
                        resolver->fontSelector()->addFontFaceRule(fontFaceRule);
                        resolver->invalidateMatchedPropertiesCache();
                    } else if (childRule->isKeyframesRule() && resolver) {
                        // Add this keyframe rule to our set.
                        // FIXME(BUG 72462): We don't add @keyframe rules of scoped style sheets for the moment.
                        if (scope)
                            continue;
                        resolver->addKeyframeStyle(static_cast<StyleRuleKeyframes*>(childRule));
                    }
                } // for rules
            } // if rules
        } else if (rule->isFontFaceRule() && resolver) {
            // Add this font face to our set.
            // FIXME(BUG 72461): We don't add @font-face rules of scoped style sheets for the moment.
            if (scope)
                continue;
            const StyleRuleFontFace* fontFaceRule = static_cast<StyleRuleFontFace*>(rule);
            resolver->fontSelector()->addFontFaceRule(fontFaceRule);
            resolver->invalidateMatchedPropertiesCache();
        } else if (rule->isKeyframesRule() && resolver) {
            // FIXME (BUG 72462): We don't add @keyframe rules of scoped style sheets for the moment.
            if (scope)
                continue;
            resolver->addKeyframeStyle(static_cast<StyleRuleKeyframes*>(rule));
        }
#if ENABLE(CSS_REGIONS)
        else if (rule->isRegionRule() && resolver) {
            // FIXME (BUG 72472): We don't add @-webkit-region rules of scoped style sheets for the moment.
            if (scope)
                continue;
            addRegionRule(static_cast<StyleRuleRegion*>(rule), hasDocumentSecurityOrigin);
        }
#endif
    }
    if (m_autoShrinkToFitEnabled)
        shrinkToFit();
}

void RuleSet::addStyleRule(StyleRule* rule, bool hasDocumentSecurityOrigin, bool canUseFastCheckSelector, bool isInRegionRule)
{
    for (size_t selectorIndex = 0; selectorIndex != notFound; selectorIndex = rule->selectorList().indexOfNextSelectorAfter(selectorIndex))
        addRule(rule, selectorIndex, hasDocumentSecurityOrigin, canUseFastCheckSelector, isInRegionRule);
}

static inline void shrinkMapVectorsToFit(RuleSet::AtomRuleMap& map)
{
    RuleSet::AtomRuleMap::iterator end = map.end();
    for (RuleSet::AtomRuleMap::iterator it = map.begin(); it != end; ++it)
        it->value->shrinkToFit();
}

void RuleSet::shrinkToFit()
{
    shrinkMapVectorsToFit(m_idRules);
    shrinkMapVectorsToFit(m_classRules);
    shrinkMapVectorsToFit(m_tagRules);
    shrinkMapVectorsToFit(m_shadowPseudoElementRules);
    m_linkPseudoClassRules.shrinkToFit();
    m_focusPseudoClassRules.shrinkToFit();
    m_universalRules.shrinkToFit();
    m_pageRules.shrinkToFit();
}

} // namespace WebCore