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/fetch/CSSStyleSheetResource.h" 29 30 #include "core/css/StyleSheetContents.h" 31 #include "core/fetch/ResourceClientWalker.h" 32 #include "core/fetch/StyleSheetResourceClient.h" 33 #include "platform/SharedBuffer.h" 34 #include "platform/network/HTTPParsers.h" 35 #include "wtf/CurrentTime.h" 36 37 namespace blink { 38 39 CSSStyleSheetResource::CSSStyleSheetResource(const ResourceRequest& resourceRequest, const String& charset) 40 : StyleSheetResource(resourceRequest, CSSStyleSheet, "text/css", charset) 41 { 42 DEFINE_STATIC_LOCAL(const AtomicString, acceptCSS, ("text/css,*/*;q=0.1", AtomicString::ConstructFromLiteral)); 43 44 // Prefer text/css but accept any type (dell.com serves a stylesheet 45 // as text/html; see <http://bugs.webkit.org/show_bug.cgi?id=11451>). 46 setAccept(acceptCSS); 47 } 48 49 CSSStyleSheetResource::~CSSStyleSheetResource() 50 { 51 // Make sure dispose() was cllaed before destruction. 52 ASSERT(!m_parsedStyleSheetCache); 53 } 54 55 void CSSStyleSheetResource::dispose() 56 { 57 if (m_parsedStyleSheetCache) 58 m_parsedStyleSheetCache->removedFromMemoryCache(); 59 m_parsedStyleSheetCache.clear(); 60 } 61 62 void CSSStyleSheetResource::trace(Visitor* visitor) 63 { 64 visitor->trace(m_parsedStyleSheetCache); 65 StyleSheetResource::trace(visitor); 66 } 67 68 void CSSStyleSheetResource::didAddClient(ResourceClient* c) 69 { 70 ASSERT(c->resourceClientType() == StyleSheetResourceClient::expectedType()); 71 // Resource::didAddClient() must be before setCSSStyleSheet(), 72 // because setCSSStyleSheet() may cause scripts to be executed, which could destroy 'c' if it is an instance of HTMLLinkElement. 73 // see the comment of HTMLLinkElement::setCSSStyleSheet. 74 Resource::didAddClient(c); 75 76 if (!isLoading()) 77 static_cast<StyleSheetResourceClient*>(c)->setCSSStyleSheet(m_resourceRequest.url(), m_response.url(), encoding(), this); 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 return decodedText(); 92 } 93 94 void CSSStyleSheetResource::checkNotify() 95 { 96 // Decode the data to find out the encoding and keep the sheet text around during checkNotify() 97 if (m_data) 98 m_decodedSheetText = decodedText(); 99 100 ResourceClientWalker<StyleSheetResourceClient> w(m_clients); 101 while (StyleSheetResourceClient* c = w.next()) 102 c->setCSSStyleSheet(m_resourceRequest.url(), m_response.url(), encoding(), this); 103 // Clear the decoded text as it is unlikely to be needed immediately again and is cheap to regenerate. 104 m_decodedSheetText = String(); 105 } 106 107 bool CSSStyleSheetResource::isSafeToUnlock() const 108 { 109 return m_data->hasOneRef(); 110 } 111 112 void CSSStyleSheetResource::destroyDecodedDataIfPossible() 113 { 114 if (!m_parsedStyleSheetCache) 115 return; 116 117 m_parsedStyleSheetCache->removedFromMemoryCache(); 118 m_parsedStyleSheetCache.clear(); 119 120 setDecodedSize(0); 121 } 122 123 bool CSSStyleSheetResource::canUseSheet(bool enforceMIMEType, bool* hasValidMIMEType) const 124 { 125 if (errorOccurred()) 126 return false; 127 128 if (!enforceMIMEType && !hasValidMIMEType) 129 return true; 130 131 // This check exactly matches Firefox. Note that we grab the Content-Type 132 // header directly because we want to see what the value is BEFORE content 133 // sniffing. Firefox does this by setting a "type hint" on the channel. 134 // This implementation should be observationally equivalent. 135 // 136 // This code defaults to allowing the stylesheet for non-HTTP protocols so 137 // folks can use standards mode for local HTML documents. 138 const AtomicString& mimeType = extractMIMETypeFromMediaType(response().httpHeaderField("Content-Type")); 139 bool typeOK = mimeType.isEmpty() || equalIgnoringCase(mimeType, "text/css") || equalIgnoringCase(mimeType, "application/x-unknown-content-type"); 140 if (hasValidMIMEType) 141 *hasValidMIMEType = typeOK; 142 if (!enforceMIMEType) 143 return true; 144 return typeOK; 145 } 146 147 PassRefPtrWillBeRawPtr<StyleSheetContents> CSSStyleSheetResource::restoreParsedStyleSheet(const CSSParserContext& context) 148 { 149 if (!m_parsedStyleSheetCache) 150 return nullptr; 151 if (m_parsedStyleSheetCache->hasFailedOrCanceledSubresources()) { 152 m_parsedStyleSheetCache->removedFromMemoryCache(); 153 m_parsedStyleSheetCache.clear(); 154 return nullptr; 155 } 156 157 ASSERT(m_parsedStyleSheetCache->isCacheable()); 158 ASSERT(m_parsedStyleSheetCache->isInMemoryCache()); 159 160 // Contexts must be identical so we know we would get the same exact result if we parsed again. 161 if (m_parsedStyleSheetCache->parserContext() != context) 162 return nullptr; 163 164 didAccessDecodedData(); 165 166 return m_parsedStyleSheetCache; 167 } 168 169 void CSSStyleSheetResource::saveParsedStyleSheet(PassRefPtrWillBeRawPtr<StyleSheetContents> sheet) 170 { 171 ASSERT(sheet && sheet->isCacheable()); 172 173 if (m_parsedStyleSheetCache) 174 m_parsedStyleSheetCache->removedFromMemoryCache(); 175 m_parsedStyleSheetCache = sheet; 176 m_parsedStyleSheetCache->addedToMemoryCache(); 177 178 setDecodedSize(m_parsedStyleSheetCache->estimatedSizeInBytes()); 179 } 180 181 } 182
