1/*
2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3 * (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
4 * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
5 * Copyright (C) 2005-2012, 2014 Apple Inc. All rights reserved.
6 * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
7 * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
8 * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
9 * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
10 * Copyright (C) Research In Motion Limited 2011. All rights reserved.
11 * Copyright (C) 2012 Google Inc. All rights reserved.
12 *
13 * This library is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU Library General Public
15 * License as published by the Free Software Foundation; either
16 * version 2 of the License, or (at your option) any later version.
17 *
18 * This library is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * Library General Public License for more details.
22 *
23 * You should have received a copy of the GNU Library General Public License
24 * along with this library; see the file COPYING.LIB. If not, write to
25 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
26 * Boston, MA 02110-1301, USA.
27 */
28
29#include "config.h"
30#include "RuleFeature.h"
31
32#include "CSSSelector.h"
33#include "CSSSelectorList.h"
34#include "RuleSet.h"
35
36namespace WebCore {
37
38static bool isSiblingOrSubject(MatchElement matchElement)
39{
40 switch (matchElement) {
41 case MatchElement::Subject:
42 case MatchElement::IndirectSibling:
43 case MatchElement::DirectSibling:
44 case MatchElement::AnySibling:
45 return true;
46 case MatchElement::Parent:
47 case MatchElement::Ancestor:
48 case MatchElement::ParentSibling:
49 case MatchElement::AncestorSibling:
50 case MatchElement::Host:
51 return false;
52 }
53 ASSERT_NOT_REACHED();
54 return false;
55}
56
57MatchElement RuleFeatureSet::computeNextMatchElement(MatchElement matchElement, CSSSelector::RelationType relation)
58{
59 if (isSiblingOrSubject(matchElement)) {
60 switch (relation) {
61 case CSSSelector::Subselector:
62 return matchElement;
63 case CSSSelector::DescendantSpace:
64 return MatchElement::Ancestor;
65 case CSSSelector::Child:
66 return MatchElement::Parent;
67 case CSSSelector::IndirectAdjacent:
68 if (matchElement == MatchElement::AnySibling)
69 return MatchElement::AnySibling;
70 return MatchElement::IndirectSibling;
71 case CSSSelector::DirectAdjacent:
72 if (matchElement == MatchElement::AnySibling)
73 return MatchElement::AnySibling;
74 return matchElement == MatchElement::Subject ? MatchElement::DirectSibling : MatchElement::IndirectSibling;
75 case CSSSelector::ShadowDescendant:
76 return MatchElement::Host;
77 };
78 }
79 switch (relation) {
80 case CSSSelector::Subselector:
81 return matchElement;
82 case CSSSelector::DescendantSpace:
83 case CSSSelector::Child:
84 return MatchElement::Ancestor;
85 case CSSSelector::IndirectAdjacent:
86 case CSSSelector::DirectAdjacent:
87 return matchElement == MatchElement::Parent ? MatchElement::ParentSibling : MatchElement::AncestorSibling;
88 case CSSSelector::ShadowDescendant:
89 return MatchElement::Host;
90 };
91 ASSERT_NOT_REACHED();
92 return matchElement;
93};
94
95MatchElement RuleFeatureSet::computeSubSelectorMatchElement(MatchElement matchElement, const CSSSelector& selector)
96{
97 ASSERT(selector.selectorList());
98
99 if (selector.match() == CSSSelector::PseudoClass) {
100 auto type = selector.pseudoClassType();
101 // For :nth-child(n of .some-subselector) where an element change may affect other elements similar to sibling combinators.
102 if (type == CSSSelector::PseudoClassNthChild || type == CSSSelector::PseudoClassNthLastChild)
103 return MatchElement::AnySibling;
104
105 // Similarly for :host().
106 if (type == CSSSelector::PseudoClassHost)
107 return MatchElement::Host;
108 }
109 if (selector.match() == CSSSelector::PseudoElement) {
110 // Similarly for ::slotted().
111 if (selector.pseudoElementType() == CSSSelector::PseudoElementSlotted)
112 return MatchElement::Host;
113 }
114
115 return matchElement;
116};
117
118void RuleFeatureSet::recursivelyCollectFeaturesFromSelector(SelectorFeatures& selectorFeatures, const CSSSelector& firstSelector, MatchElement matchElement)
119{
120 const CSSSelector* selector = &firstSelector;
121 do {
122 if (selector->match() == CSSSelector::Id) {
123 idsInRules.add(selector->value());
124 if (matchElement == MatchElement::Parent || matchElement == MatchElement::Ancestor)
125 idsMatchingAncestorsInRules.add(selector->value());
126 } else if (selector->match() == CSSSelector::Class)
127 selectorFeatures.classes.append(std::make_pair(selector->value(), matchElement));
128 else if (selector->isAttributeSelector()) {
129 auto& canonicalLocalName = selector->attributeCanonicalLocalName();
130 auto& localName = selector->attribute().localName();
131 attributeCanonicalLocalNamesInRules.add(canonicalLocalName);
132 attributeLocalNamesInRules.add(localName);
133 selectorFeatures.attributes.append(std::make_pair(selector, matchElement));
134 } else if (selector->match() == CSSSelector::PseudoElement) {
135 switch (selector->pseudoElementType()) {
136 case CSSSelector::PseudoElementFirstLine:
137 usesFirstLineRules = true;
138 break;
139 case CSSSelector::PseudoElementFirstLetter:
140 usesFirstLetterRules = true;
141 break;
142 default:
143 break;
144 }
145 }
146
147 if (!selectorFeatures.hasSiblingSelector && selector->isSiblingSelector())
148 selectorFeatures.hasSiblingSelector = true;
149
150 if (const CSSSelectorList* selectorList = selector->selectorList()) {
151 auto subSelectorMatchElement = computeSubSelectorMatchElement(matchElement, *selector);
152
153 for (const CSSSelector* subSelector = selectorList->first(); subSelector; subSelector = CSSSelectorList::next(subSelector)) {
154 if (!selectorFeatures.hasSiblingSelector && selector->isSiblingSelector())
155 selectorFeatures.hasSiblingSelector = true;
156 recursivelyCollectFeaturesFromSelector(selectorFeatures, *subSelector, subSelectorMatchElement);
157 }
158 }
159
160 matchElement = computeNextMatchElement(matchElement, selector->relation());
161
162 selector = selector->tagHistory();
163 } while (selector);
164}
165
166void RuleFeatureSet::collectFeatures(const RuleData& ruleData)
167{
168 SelectorFeatures selectorFeatures;
169 recursivelyCollectFeaturesFromSelector(selectorFeatures, *ruleData.selector());
170 if (selectorFeatures.hasSiblingSelector)
171 siblingRules.append(RuleFeature(ruleData.rule(), ruleData.selectorIndex(), ruleData.selectorListIndex()));
172 if (ruleData.containsUncommonAttributeSelector())
173 uncommonAttributeRules.append(RuleFeature(ruleData.rule(), ruleData.selectorIndex(), ruleData.selectorListIndex()));
174
175 for (auto& nameAndMatch : selectorFeatures.classes) {
176 classRules.ensure(nameAndMatch.first, [] {
177 return std::make_unique<Vector<RuleFeature>>();
178 }).iterator->value->append(RuleFeature(ruleData.rule(), ruleData.selectorIndex(), ruleData.selectorListIndex(), nameAndMatch.second));
179 if (nameAndMatch.second == MatchElement::Host)
180 classesAffectingHost.add(nameAndMatch.first);
181 }
182 for (auto& selectorAndMatch : selectorFeatures.attributes) {
183 auto* selector = selectorAndMatch.first;
184 auto matchElement = selectorAndMatch.second;
185 attributeRules.ensure(selector->attribute().localName().convertToASCIILowercase(), [] {
186 return std::make_unique<Vector<RuleFeature>>();
187 }).iterator->value->append(RuleFeature(ruleData.rule(), ruleData.selectorIndex(), ruleData.selectorListIndex(), matchElement, selector));
188 if (matchElement == MatchElement::Host)
189 attributesAffectingHost.add(selector->attribute().localName().convertToASCIILowercase());
190 }
191}
192
193void RuleFeatureSet::add(const RuleFeatureSet& other)
194{
195 idsInRules.add(other.idsInRules.begin(), other.idsInRules.end());
196 idsMatchingAncestorsInRules.add(other.idsMatchingAncestorsInRules.begin(), other.idsMatchingAncestorsInRules.end());
197 attributeCanonicalLocalNamesInRules.add(other.attributeCanonicalLocalNamesInRules.begin(), other.attributeCanonicalLocalNamesInRules.end());
198 attributeLocalNamesInRules.add(other.attributeLocalNamesInRules.begin(), other.attributeLocalNamesInRules.end());
199 contentAttributeNamesInRules.add(other.contentAttributeNamesInRules.begin(), other.contentAttributeNamesInRules.end());
200 siblingRules.appendVector(other.siblingRules);
201 uncommonAttributeRules.appendVector(other.uncommonAttributeRules);
202 for (auto& keyValuePair : other.classRules) {
203 classRules.ensure(keyValuePair.key, [] {
204 return std::make_unique<Vector<RuleFeature>>();
205 }).iterator->value->appendVector(*keyValuePair.value);
206 }
207 classesAffectingHost.add(other.classesAffectingHost.begin(), other.classesAffectingHost.end());
208
209 for (auto& keyValuePair : other.attributeRules) {
210 attributeRules.ensure(keyValuePair.key, [] {
211 return std::make_unique<Vector<RuleFeature>>();
212 }).iterator->value->appendVector(*keyValuePair.value);
213 }
214 attributesAffectingHost.add(other.attributesAffectingHost.begin(), other.attributesAffectingHost.end());
215
216 usesFirstLineRules = usesFirstLineRules || other.usesFirstLineRules;
217 usesFirstLetterRules = usesFirstLetterRules || other.usesFirstLetterRules;
218}
219
220void RuleFeatureSet::registerContentAttribute(const AtomicString& attributeName)
221{
222 contentAttributeNamesInRules.add(attributeName.convertToASCIILowercase());
223 attributeCanonicalLocalNamesInRules.add(attributeName);
224 attributeLocalNamesInRules.add(attributeName);
225}
226
227void RuleFeatureSet::clear()
228{
229 idsInRules.clear();
230 idsMatchingAncestorsInRules.clear();
231 attributeCanonicalLocalNamesInRules.clear();
232 attributeLocalNamesInRules.clear();
233 contentAttributeNamesInRules.clear();
234 siblingRules.clear();
235 uncommonAttributeRules.clear();
236 classRules.clear();
237 classesAffectingHost.clear();
238 attributeRules.clear();
239 attributesAffectingHost.clear();
240 usesFirstLineRules = false;
241 usesFirstLetterRules = false;
242}
243
244void RuleFeatureSet::shrinkToFit()
245{
246 siblingRules.shrinkToFit();
247 uncommonAttributeRules.shrinkToFit();
248 for (auto& rules : classRules.values())
249 rules->shrinkToFit();
250 for (auto& rules : attributeRules.values())
251 rules->shrinkToFit();
252}
253
254} // namespace WebCore
255