1/* 2 Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de) 3 Copyright (C) 2001 Dirk Mueller (mueller@kde.org) 4 Copyright (C) 2002 Waldo Bastian (bastian@kde.org) 5 Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com) 6 Copyright (C) 2004, 2005, 2006 Apple Inc. 7 8 This library is free software; you can redistribute it and/or 9 modify it under the terms of the GNU Library General Public 10 License as published by the Free Software Foundation; either 11 version 2 of the License, or (at your option) any later version. 12 13 This library is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 Library General Public License for more details. 17 18 You should have received a copy of the GNU Library General Public License 19 along with this library; see the file COPYING.LIB. If not, write to 20 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 21 Boston, MA 02110-1301, USA. 22 23 This class provides all functionality needed for loading images, style sheets and html 24 pages from the web. It has a memory cache for these objects. 25*/ 26 27#include "config.h" 28#include "CachedCSSStyleSheet.h" 29 30#include "CSSStyleSheet.h" 31#include "CachedResourceClientWalker.h" 32#include "CachedStyleSheetClient.h" 33#include "HTTPHeaderNames.h" 34#include "HTTPParsers.h" 35#include "MemoryCache.h" 36#include "ResourceBuffer.h" 37#include "StyleSheetContents.h" 38#include "TextResourceDecoder.h" 39#include <wtf/CurrentTime.h> 40#include <wtf/Vector.h> 41 42namespace WebCore { 43 44CachedCSSStyleSheet::CachedCSSStyleSheet(const ResourceRequest& resourceRequest, const String& charset, SessionID sessionID) 45 : CachedResource(resourceRequest, CSSStyleSheet, sessionID) 46 , m_decoder(TextResourceDecoder::create("text/css", charset)) 47{ 48 // Prefer text/css but accept any type (dell.com serves a stylesheet 49 // as text/html; see <http://bugs.webkit.org/show_bug.cgi?id=11451>). 50 setAccept("text/css,*/*;q=0.1"); 51} 52 53CachedCSSStyleSheet::~CachedCSSStyleSheet() 54{ 55 if (m_parsedStyleSheetCache) 56 m_parsedStyleSheetCache->removedFromMemoryCache(); 57} 58 59void CachedCSSStyleSheet::didAddClient(CachedResourceClient* c) 60{ 61 ASSERT(c->resourceClientType() == CachedStyleSheetClient::expectedType()); 62 // CachedResource::didAddClient() must be before setCSSStyleSheet(), 63 // because setCSSStyleSheet() may cause scripts to be executed, which could destroy 'c' if it is an instance of HTMLLinkElement. 64 // see the comment of HTMLLinkElement::setCSSStyleSheet. 65 CachedResource::didAddClient(c); 66 67 if (!isLoading()) 68 static_cast<CachedStyleSheetClient*>(c)->setCSSStyleSheet(m_resourceRequest.url(), m_response.url(), m_decoder->encoding().name(), this); 69} 70 71void CachedCSSStyleSheet::setEncoding(const String& chs) 72{ 73 m_decoder->setEncoding(chs, TextResourceDecoder::EncodingFromHTTPHeader); 74} 75 76String CachedCSSStyleSheet::encoding() const 77{ 78 return m_decoder->encoding().name(); 79} 80 81const String CachedCSSStyleSheet::sheetText(bool enforceMIMEType, bool* hasValidMIMEType) const 82{ 83 ASSERT(!isPurgeable()); 84 85 if (!m_data || m_data->isEmpty() || !canUseSheet(enforceMIMEType, hasValidMIMEType)) 86 return String(); 87 88 if (!m_decodedSheetText.isNull()) 89 return m_decodedSheetText; 90 91 // Don't cache the decoded text, regenerating is cheap and it can use quite a bit of memory 92 return m_decoder->decodeAndFlush(m_data->data(), m_data->size()); 93} 94 95void CachedCSSStyleSheet::finishLoading(ResourceBuffer* data) 96{ 97 m_data = data; 98 setEncodedSize(m_data.get() ? m_data->size() : 0); 99 // Decode the data to find out the encoding and keep the sheet text around during checkNotify() 100 if (m_data) 101 m_decodedSheetText = m_decoder->decodeAndFlush(m_data->data(), m_data->size()); 102 setLoading(false); 103 checkNotify(); 104 // Clear the decoded text as it is unlikely to be needed immediately again and is cheap to regenerate. 105 m_decodedSheetText = String(); 106} 107 108void CachedCSSStyleSheet::checkNotify() 109{ 110 if (isLoading()) 111 return; 112 113 CachedResourceClientWalker<CachedStyleSheetClient> w(m_clients); 114 while (CachedStyleSheetClient* c = w.next()) 115 c->setCSSStyleSheet(m_resourceRequest.url(), m_response.url(), m_decoder->encoding().name(), this); 116} 117 118bool CachedCSSStyleSheet::canUseSheet(bool enforceMIMEType, bool* hasValidMIMEType) const 119{ 120 if (errorOccurred()) 121 return false; 122 123 if (!enforceMIMEType && !hasValidMIMEType) 124 return true; 125 126 // This check exactly matches Firefox. Note that we grab the Content-Type 127 // header directly because we want to see what the value is BEFORE content 128 // sniffing. Firefox does this by setting a "type hint" on the channel. 129 // This implementation should be observationally equivalent. 130 // 131 // This code defaults to allowing the stylesheet for non-HTTP protocols so 132 // folks can use standards mode for local HTML documents. 133 String mimeType = extractMIMETypeFromMediaType(response().httpHeaderField(HTTPHeaderName::ContentType)); 134 bool typeOK = mimeType.isEmpty() || equalIgnoringCase(mimeType, "text/css") || equalIgnoringCase(mimeType, "application/x-unknown-content-type"); 135 if (hasValidMIMEType) 136 *hasValidMIMEType = typeOK; 137 if (!enforceMIMEType) 138 return true; 139 return typeOK; 140} 141 142void CachedCSSStyleSheet::destroyDecodedData() 143{ 144 if (!m_parsedStyleSheetCache) 145 return; 146 147 m_parsedStyleSheetCache->removedFromMemoryCache(); 148 m_parsedStyleSheetCache.clear(); 149 150 setDecodedSize(0); 151 152 if (!MemoryCache::shouldMakeResourcePurgeableOnEviction() && isSafeToMakePurgeable()) 153 makePurgeable(true); 154} 155 156PassRefPtr<StyleSheetContents> CachedCSSStyleSheet::restoreParsedStyleSheet(const CSSParserContext& context) 157{ 158 if (!m_parsedStyleSheetCache) 159 return 0; 160 if (m_parsedStyleSheetCache->hasFailedOrCanceledSubresources()) { 161 m_parsedStyleSheetCache->removedFromMemoryCache(); 162 m_parsedStyleSheetCache.clear(); 163 return 0; 164 } 165 166 ASSERT(m_parsedStyleSheetCache->isCacheable()); 167 ASSERT(m_parsedStyleSheetCache->isInMemoryCache()); 168 169 // Contexts must be identical so we know we would get the same exact result if we parsed again. 170 if (m_parsedStyleSheetCache->parserContext() != context) 171 return 0; 172 173 didAccessDecodedData(monotonicallyIncreasingTime()); 174 175 return m_parsedStyleSheetCache; 176} 177 178void CachedCSSStyleSheet::saveParsedStyleSheet(PassRef<StyleSheetContents> sheet) 179{ 180 ASSERT(sheet.get().isCacheable()); 181 182 if (m_parsedStyleSheetCache) 183 m_parsedStyleSheetCache->removedFromMemoryCache(); 184 m_parsedStyleSheetCache = WTF::move(sheet); 185 m_parsedStyleSheetCache->addedToMemoryCache(); 186 187 setDecodedSize(m_parsedStyleSheetCache->estimatedSizeInBytes()); 188} 189 190} 191