blob: 150a78d590316c7e14419d82acb79b804c62b8af [file] [log] [blame]
/*
* Copyright (C) 2006, 2007 Rob Buis
* Copyright (C) 2008-2016 Apple, 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 "InlineStyleSheetOwner.h"
#include "ContentSecurityPolicy.h"
#include "Element.h"
#include "Logging.h"
#include "MediaList.h"
#include "MediaQueryEvaluator.h"
#include "MediaQueryParser.h"
#include "ScriptableDocumentParser.h"
#include "ShadowRoot.h"
#include "StyleScope.h"
#include "StyleSheetContents.h"
#include "TextNodeTraversal.h"
#include <wtf/HashMap.h>
#include <wtf/NeverDestroyed.h>
namespace WebCore {
using InlineStyleSheetCacheKey = std::pair<String, CSSParserContext>;
using InlineStyleSheetCache = HashMap<InlineStyleSheetCacheKey, RefPtr<StyleSheetContents>>;
static InlineStyleSheetCache& inlineStyleSheetCache()
{
static NeverDestroyed<InlineStyleSheetCache> cache;
return cache;
}
static CSSParserContext parserContextForElement(const Element& element)
{
auto* shadowRoot = element.containingShadowRoot();
// User agent shadow trees can't contain document-relative URLs. Use blank URL as base allowing cross-document sharing.
auto& baseURL = shadowRoot && shadowRoot->mode() == ShadowRootMode::UserAgent ? WTF::blankURL() : element.document().baseURL();
CSSParserContext result = CSSParserContext { element.document(), baseURL, element.document().characterSetWithUTF8Fallback() };
if (shadowRoot && shadowRoot->mode() == ShadowRootMode::UserAgent)
result.mode = UASheetMode;
return result;
}
static Optional<InlineStyleSheetCacheKey> makeInlineStyleSheetCacheKey(const String& text, const Element& element)
{
// Only cache for shadow trees. Main document inline stylesheets are generally unique and can't be shared between documents.
// FIXME: This could be relaxed when a stylesheet does not contain document-relative URLs (or #urls).
if (!element.isInShadowTree())
return { };
return std::make_pair(text, parserContextForElement(element));
}
InlineStyleSheetOwner::InlineStyleSheetOwner(Document& document, bool createdByParser)
: m_isParsingChildren(createdByParser)
, m_loading(false)
, m_startTextPosition()
{
if (createdByParser && document.scriptableDocumentParser() && !document.isInDocumentWrite())
m_startTextPosition = document.scriptableDocumentParser()->textPosition();
}
InlineStyleSheetOwner::~InlineStyleSheetOwner()
{
if (m_sheet)
clearSheet();
}
void InlineStyleSheetOwner::insertedIntoDocument(Element& element)
{
m_styleScope = &Style::Scope::forNode(element);
m_styleScope->addStyleSheetCandidateNode(element, m_isParsingChildren);
if (m_isParsingChildren)
return;
createSheetFromTextContents(element);
}
void InlineStyleSheetOwner::removedFromDocument(Element& element)
{
if (m_styleScope) {
m_styleScope->removeStyleSheetCandidateNode(element);
m_styleScope = nullptr;
}
if (m_sheet)
clearSheet();
}
void InlineStyleSheetOwner::clearDocumentData(Element& element)
{
if (m_sheet)
m_sheet->clearOwnerNode();
if (m_styleScope) {
m_styleScope->removeStyleSheetCandidateNode(element);
m_styleScope = nullptr;
}
}
void InlineStyleSheetOwner::childrenChanged(Element& element)
{
if (m_isParsingChildren)
return;
if (!element.isConnected())
return;
createSheetFromTextContents(element);
}
void InlineStyleSheetOwner::finishParsingChildren(Element& element)
{
if (element.isConnected())
createSheetFromTextContents(element);
m_isParsingChildren = false;
}
void InlineStyleSheetOwner::createSheetFromTextContents(Element& element)
{
createSheet(element, TextNodeTraversal::contentsAsString(element));
}
void InlineStyleSheetOwner::clearSheet()
{
ASSERT(m_sheet);
auto sheet = WTFMove(m_sheet);
sheet->clearOwnerNode();
}
inline bool isValidCSSContentType(Element& element, const AtomicString& type)
{
if (type.isEmpty())
return true;
// FIXME: Should MIME types really be case sensitive in XML documents? Doesn't seem like they should,
// even though other things are case sensitive in that context. MIME types should never be case sensitive.
// We should verify this and then remove the isHTMLElement check here.
static NeverDestroyed<const AtomicString> cssContentType("text/css", AtomicString::ConstructFromLiteral);
return element.isHTMLElement() ? equalLettersIgnoringASCIICase(type, "text/css") : type == cssContentType;
}
void InlineStyleSheetOwner::createSheet(Element& element, const String& text)
{
ASSERT(element.isConnected());
Document& document = element.document();
if (m_sheet) {
if (m_sheet->isLoading() && m_styleScope)
m_styleScope->removePendingSheet(element);
clearSheet();
}
if (!isValidCSSContentType(element, m_contentType))
return;
ASSERT(document.contentSecurityPolicy());
const ContentSecurityPolicy& contentSecurityPolicy = *document.contentSecurityPolicy();
bool hasKnownNonce = contentSecurityPolicy.allowStyleWithNonce(element.attributeWithoutSynchronization(HTMLNames::nonceAttr), element.isInUserAgentShadowTree());
if (!contentSecurityPolicy.allowInlineStyle(document.url(), m_startTextPosition.m_line, text, hasKnownNonce))
return;
auto mediaQueries = MediaQuerySet::create(m_media, MediaQueryParserContext(document));
MediaQueryEvaluator screenEval("screen"_s, true);
MediaQueryEvaluator printEval("print"_s, true);
LOG(MediaQueries, "InlineStyleSheetOwner::createSheet evaluating queries");
if (!screenEval.evaluate(mediaQueries.get()) && !printEval.evaluate(mediaQueries.get()))
return;
if (m_styleScope)
m_styleScope->addPendingSheet(element);
auto cacheKey = makeInlineStyleSheetCacheKey(text, element);
if (cacheKey) {
if (auto* cachedSheet = inlineStyleSheetCache().get(*cacheKey)) {
ASSERT(cachedSheet->isCacheable());
m_sheet = CSSStyleSheet::createInline(*cachedSheet, element, m_startTextPosition);
m_sheet->setMediaQueries(WTFMove(mediaQueries));
if (!element.isInShadowTree())
m_sheet->setTitle(element.title());
sheetLoaded(element);
element.notifyLoadedSheetAndAllCriticalSubresources(false);
return;
}
}
m_loading = true;
auto contents = StyleSheetContents::create(String(), parserContextForElement(element));
m_sheet = CSSStyleSheet::createInline(contents.get(), element, m_startTextPosition);
m_sheet->setMediaQueries(WTFMove(mediaQueries));
if (!element.isInShadowTree())
m_sheet->setTitle(element.title());
contents->parseString(text);
m_loading = false;
contents->checkLoaded();
if (cacheKey && contents->isCacheable()) {
m_sheet->contents().addedToMemoryCache();
inlineStyleSheetCache().add(*cacheKey, &m_sheet->contents());
// Prevent pathological growth.
const size_t maximumInlineStyleSheetCacheSize = 50;
if (inlineStyleSheetCache().size() > maximumInlineStyleSheetCacheSize) {
auto toRemove = inlineStyleSheetCache().random();
toRemove->value->removedFromMemoryCache();
inlineStyleSheetCache().remove(toRemove);
}
}
}
bool InlineStyleSheetOwner::isLoading() const
{
if (m_loading)
return true;
return m_sheet && m_sheet->isLoading();
}
bool InlineStyleSheetOwner::sheetLoaded(Element& element)
{
if (isLoading())
return false;
if (m_styleScope)
m_styleScope->removePendingSheet(element);
return true;
}
void InlineStyleSheetOwner::startLoadingDynamicSheet(Element& element)
{
if (m_styleScope)
m_styleScope->addPendingSheet(element);
}
void InlineStyleSheetOwner::clearCache()
{
inlineStyleSheetCache().clear();
}
}