1 /* 2 Copyright (C) 1998 Lars Knoll (knoll (at) mpi-hd.mpg.de) 3 Copyright (C) 2001 Dirk Mueller (mueller (at) kde.org) 4 Copyright (C) 2002 Waldo Bastian (bastian (at) kde.org) 5 Copyright (C) 2006 Samuel Weinig (sam.weinig (at) gmail.com) 6 Copyright (C) 2004, 2005, 2006 Apple Computer, 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 "core/loader/cache/CSSStyleSheetResource.h" 29 30 #include "core/css/StyleSheetContents.h" 31 #include "core/loader/TextResourceDecoder.h" 32 #include "core/loader/cache/ResourceClientWalker.h" 33 #include "core/loader/cache/StyleSheetResourceClient.h" 34 #include "core/platform/SharedBuffer.h" 35 #include "core/platform/network/HTTPParsers.h" 36 #include "wtf/CurrentTime.h" 37 #include "wtf/Vector.h" 38 39 namespace WebCore { 40 41 CSSStyleSheetResource::CSSStyleSheetResource(const ResourceRequest& resourceRequest, const String& charset) 42 : Resource(resourceRequest, CSSStyleSheet) 43 , m_decoder(TextResourceDecoder::create("text/css", charset)) 44 { 45 DEFINE_STATIC_LOCAL(const AtomicString, acceptCSS, ("text/css,*/*;q=0.1", AtomicString::ConstructFromLiteral)); 46 47 // Prefer text/css but accept any type (dell.com serves a stylesheet 48 // as text/html; see <http://bugs.webkit.org/show_bug.cgi?id=11451>). 49 setAccept(acceptCSS); 50 } 51 52 CSSStyleSheetResource::~CSSStyleSheetResource() 53 { 54 if (m_parsedStyleSheetCache) 55 m_parsedStyleSheetCache->removedFromMemoryCache(); 56 } 57 58 void CSSStyleSheetResource::didAddClient(ResourceClient* c) 59 { 60 ASSERT(c->resourceClientType() == StyleSheetResourceClient::expectedType()); 61 // Resource::didAddClient() must be before setCSSStyleSheet(), 62 // because setCSSStyleSheet() may cause scripts to be executed, which could destroy 'c' if it is an instance of HTMLLinkElement. 63 // see the comment of HTMLLinkElement::setCSSStyleSheet. 64 Resource::didAddClient(c); 65 66 if (!isLoading()) 67 static_cast<StyleSheetResourceClient*>(c)->setCSSStyleSheet(m_resourceRequest.url(), m_response.url(), m_decoder->encoding().name(), this); 68 } 69 70 void CSSStyleSheetResource::setEncoding(const String& chs) 71 { 72 m_decoder->setEncoding(chs, TextResourceDecoder::EncodingFromHTTPHeader); 73 } 74 75 String CSSStyleSheetResource::encoding() const 76 { 77 return m_decoder->encoding().name(); 78 } 79 80 const String CSSStyleSheetResource::sheetText(bool enforceMIMEType, bool* hasValidMIMEType) const 81 { 82 ASSERT(!isPurgeable()); 83 84 if (!m_data || m_data->isEmpty() || !canUseSheet(enforceMIMEType, hasValidMIMEType)) 85 return String(); 86 87 if (!m_decodedSheetText.isNull()) 88 return m_decodedSheetText; 89 90 // Don't cache the decoded text, regenerating is cheap and it can use quite a bit of memory 91 String sheetText = m_decoder->decode(m_data->data(), m_data->size()); 92 sheetText.append(m_decoder->flush()); 93 return sheetText; 94 } 95 96 void CSSStyleSheetResource::checkNotify() 97 { 98 // Decode the data to find out the encoding and keep the sheet text around during checkNotify() 99 if (m_data) { 100 m_decodedSheetText = m_decoder->decode(m_data->data(), m_data->size()); 101 m_decodedSheetText.append(m_decoder->flush()); 102 } 103 104 ResourceClientWalker<StyleSheetResourceClient> w(m_clients); 105 while (StyleSheetResourceClient* c = w.next()) 106 c->setCSSStyleSheet(m_resourceRequest.url(), m_response.url(), m_decoder->encoding().name(), this); 107 // Clear the decoded text as it is unlikely to be needed immediately again and is cheap to regenerate. 108 m_decodedSheetText = String(); 109 } 110 111 bool CSSStyleSheetResource::canUseSheet(bool enforceMIMEType, bool* hasValidMIMEType) const 112 { 113 if (errorOccurred()) 114 return false; 115 116 if (!enforceMIMEType && !hasValidMIMEType) 117 return true; 118 119 // This check exactly matches Firefox. Note that we grab the Content-Type 120 // header directly because we want to see what the value is BEFORE content 121 // sniffing. Firefox does this by setting a "type hint" on the channel. 122 // This implementation should be observationally equivalent. 123 // 124 // This code defaults to allowing the stylesheet for non-HTTP protocols so 125 // folks can use standards mode for local HTML documents. 126 String mimeType = extractMIMETypeFromMediaType(response().httpHeaderField("Content-Type")); 127 bool typeOK = mimeType.isEmpty() || equalIgnoringCase(mimeType, "text/css") || equalIgnoringCase(mimeType, "application/x-unknown-content-type"); 128 if (hasValidMIMEType) 129 *hasValidMIMEType = typeOK; 130 if (!enforceMIMEType) 131 return true; 132 return typeOK; 133 } 134 135 void CSSStyleSheetResource::destroyDecodedData() 136 { 137 if (!m_parsedStyleSheetCache) 138 return; 139 140 m_parsedStyleSheetCache->removedFromMemoryCache(); 141 m_parsedStyleSheetCache.clear(); 142 143 setDecodedSize(0); 144 145 if (isSafeToMakePurgeable()) 146 makePurgeable(true); 147 } 148 149 PassRefPtr<StyleSheetContents> CSSStyleSheetResource::restoreParsedStyleSheet(const CSSParserContext& context) 150 { 151 if (!m_parsedStyleSheetCache) 152 return 0; 153 if (m_parsedStyleSheetCache->hasFailedOrCanceledSubresources()) { 154 m_parsedStyleSheetCache->removedFromMemoryCache(); 155 m_parsedStyleSheetCache.clear(); 156 return 0; 157 } 158 159 ASSERT(m_parsedStyleSheetCache->isCacheable()); 160 ASSERT(m_parsedStyleSheetCache->isInMemoryCache()); 161 162 // Contexts must be identical so we know we would get the same exact result if we parsed again. 163 if (m_parsedStyleSheetCache->parserContext() != context) 164 return 0; 165 166 didAccessDecodedData(currentTime()); 167 168 return m_parsedStyleSheetCache; 169 } 170 171 void CSSStyleSheetResource::saveParsedStyleSheet(PassRefPtr<StyleSheetContents> sheet) 172 { 173 ASSERT(sheet && sheet->isCacheable()); 174 175 if (m_parsedStyleSheetCache) 176 m_parsedStyleSheetCache->removedFromMemoryCache(); 177 m_parsedStyleSheetCache = sheet; 178 m_parsedStyleSheetCache->addedToMemoryCache(); 179 180 setDecodedSize(m_parsedStyleSheetCache->estimatedSizeInBytes()); 181 } 182 183 } 184
