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/*
Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.
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.
This class provides all functionality needed for loading images, style sheets and html
pages from the web. It has a memory cache for these objects.
*/
#include "config.h"
#include "CachedCSSStyleSheet.h"
#include "CSSStyleSheet.h"
#include "CachedResourceClientWalker.h"
#include "CachedStyleSheetClient.h"
#include "HTTPParsers.h"
#include "MemoryCache.h"
#include "ResourceBuffer.h"
#include "StyleSheetContents.h"
#include "TextResourceDecoder.h"
#include <wtf/CurrentTime.h>
#include <wtf/Vector.h>
namespace WebCore {
CachedCSSStyleSheet::CachedCSSStyleSheet(const ResourceRequest& resourceRequest, const String& charset)
: CachedResource(resourceRequest, CSSStyleSheet)
, m_decoder(TextResourceDecoder::create("text/css", charset))
{
// Prefer text/css but accept any type (dell.com serves a stylesheet
// as text/html; see <http://bugs.webkit.org/show_bug.cgi?id=11451>).
setAccept("text/css,*/*;q=0.1");
}
CachedCSSStyleSheet::~CachedCSSStyleSheet()
{
if (m_parsedStyleSheetCache)
m_parsedStyleSheetCache->removedFromMemoryCache();
}
void CachedCSSStyleSheet::didAddClient(CachedResourceClient* c)
{
ASSERT(c->resourceClientType() == CachedStyleSheetClient::expectedType());
// CachedResource::didAddClient() must be before setCSSStyleSheet(),
// because setCSSStyleSheet() may cause scripts to be executed, which could destroy 'c' if it is an instance of HTMLLinkElement.
// see the comment of HTMLLinkElement::setCSSStyleSheet.
CachedResource::didAddClient(c);
if (!isLoading())
static_cast<CachedStyleSheetClient*>(c)->setCSSStyleSheet(m_resourceRequest.url(), m_response.url(), m_decoder->encoding().name(), this);
}
void CachedCSSStyleSheet::setEncoding(const String& chs)
{
m_decoder->setEncoding(chs, TextResourceDecoder::EncodingFromHTTPHeader);
}
String CachedCSSStyleSheet::encoding() const
{
return m_decoder->encoding().name();
}
const String CachedCSSStyleSheet::sheetText(bool enforceMIMEType, bool* hasValidMIMEType) const
{
ASSERT(!isPurgeable());
if (!m_data || m_data->isEmpty() || !canUseSheet(enforceMIMEType, hasValidMIMEType))
return String();
if (!m_decodedSheetText.isNull())
return m_decodedSheetText;
// Don't cache the decoded text, regenerating is cheap and it can use quite a bit of memory
String sheetText = m_decoder->decode(m_data->data(), m_data->size());
sheetText.append(m_decoder->flush());
return sheetText;
}
void CachedCSSStyleSheet::finishLoading(ResourceBuffer* data)
{
m_data = data;
setEncodedSize(m_data.get() ? m_data->size() : 0);
// Decode the data to find out the encoding and keep the sheet text around during checkNotify()
if (m_data) {
m_decodedSheetText = m_decoder->decode(m_data->data(), m_data->size());
m_decodedSheetText.append(m_decoder->flush());
}
setLoading(false);
checkNotify();
// Clear the decoded text as it is unlikely to be needed immediately again and is cheap to regenerate.
m_decodedSheetText = String();
}
void CachedCSSStyleSheet::checkNotify()
{
if (isLoading())
return;
CachedResourceClientWalker<CachedStyleSheetClient> w(m_clients);
while (CachedStyleSheetClient* c = w.next())
c->setCSSStyleSheet(m_resourceRequest.url(), m_response.url(), m_decoder->encoding().name(), this);
}
bool CachedCSSStyleSheet::canUseSheet(bool enforceMIMEType, bool* hasValidMIMEType) const
{
if (errorOccurred())
return false;
if (!enforceMIMEType && !hasValidMIMEType)
return true;
// This check exactly matches Firefox. Note that we grab the Content-Type
// header directly because we want to see what the value is BEFORE content
// sniffing. Firefox does this by setting a "type hint" on the channel.
// This implementation should be observationally equivalent.
//
// This code defaults to allowing the stylesheet for non-HTTP protocols so
// folks can use standards mode for local HTML documents.
String mimeType = extractMIMETypeFromMediaType(response().httpHeaderField("Content-Type"));
bool typeOK = mimeType.isEmpty() || equalIgnoringCase(mimeType, "text/css") || equalIgnoringCase(mimeType, "application/x-unknown-content-type");
if (hasValidMIMEType)
*hasValidMIMEType = typeOK;
if (!enforceMIMEType)
return true;
return typeOK;
}
void CachedCSSStyleSheet::destroyDecodedData()
{
if (!m_parsedStyleSheetCache)
return;
m_parsedStyleSheetCache->removedFromMemoryCache();
m_parsedStyleSheetCache.clear();
setDecodedSize(0);
if (!MemoryCache::shouldMakeResourcePurgeableOnEviction() && isSafeToMakePurgeable())
makePurgeable(true);
}
PassRefPtr<StyleSheetContents> CachedCSSStyleSheet::restoreParsedStyleSheet(const CSSParserContext& context)
{
if (!m_parsedStyleSheetCache)
return 0;
if (m_parsedStyleSheetCache->hasFailedOrCanceledSubresources()) {
m_parsedStyleSheetCache->removedFromMemoryCache();
m_parsedStyleSheetCache.clear();
return 0;
}
ASSERT(m_parsedStyleSheetCache->isCacheable());
ASSERT(m_parsedStyleSheetCache->isInMemoryCache());
// Contexts must be identical so we know we would get the same exact result if we parsed again.
if (m_parsedStyleSheetCache->parserContext() != context)
return 0;
didAccessDecodedData(currentTime());
return m_parsedStyleSheetCache;
}
void CachedCSSStyleSheet::saveParsedStyleSheet(PassRefPtr<StyleSheetContents> sheet)
{
ASSERT(sheet && sheet->isCacheable());
if (m_parsedStyleSheetCache)
m_parsedStyleSheetCache->removedFromMemoryCache();
m_parsedStyleSheetCache = sheet;
m_parsedStyleSheetCache->addedToMemoryCache();
setDecodedSize(m_parsedStyleSheetCache->estimatedSizeInBytes());
}
}
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