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 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 "core/fetch/TextResourceDecoder.h"
34 #include "platform/SharedBuffer.h"
35 #include "platform/network/HTTPParsers.h"
36 #include "wtf/CurrentTime.h"
37 #include "wtf/Vector.h"
38
39 namespace WebCore {
40
CSSStyleSheetResource(const ResourceRequest & resourceRequest,const String & charset)41 CSSStyleSheetResource::CSSStyleSheetResource(const ResourceRequest& resourceRequest, const String& charset)
42 : StyleSheetResource(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
~CSSStyleSheetResource()52 CSSStyleSheetResource::~CSSStyleSheetResource()
53 {
54 if (m_parsedStyleSheetCache)
55 m_parsedStyleSheetCache->removedFromMemoryCache();
56 }
57
didAddClient(ResourceClient * c)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
setEncoding(const String & chs)70 void CSSStyleSheetResource::setEncoding(const String& chs)
71 {
72 m_decoder->setEncoding(chs, TextResourceDecoder::EncodingFromHTTPHeader);
73 }
74
encoding() const75 String CSSStyleSheetResource::encoding() const
76 {
77 return m_decoder->encoding().name();
78 }
79
sheetText(bool enforceMIMEType,bool * hasValidMIMEType) const80 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
checkNotify()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
canUseSheet(bool enforceMIMEType,bool * hasValidMIMEType) const111 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 const AtomicString& 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
destroyDecodedData()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
restoreParsedStyleSheet(const CSSParserContext & context)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
saveParsedStyleSheet(PassRefPtr<StyleSheetContents> sheet)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