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 "platform/SharedBuffer.h"
34 #include "platform/network/HTTPParsers.h"
35 #include "wtf/CurrentTime.h"
36
37 namespace blink {
38
CSSStyleSheetResource(const ResourceRequest & resourceRequest,const String & charset)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
~CSSStyleSheetResource()49 CSSStyleSheetResource::~CSSStyleSheetResource()
50 {
51 // Make sure dispose() was cllaed before destruction.
52 ASSERT(!m_parsedStyleSheetCache);
53 }
54
dispose()55 void CSSStyleSheetResource::dispose()
56 {
57 if (m_parsedStyleSheetCache)
58 m_parsedStyleSheetCache->removedFromMemoryCache();
59 m_parsedStyleSheetCache.clear();
60 }
61
trace(Visitor * visitor)62 void CSSStyleSheetResource::trace(Visitor* visitor)
63 {
64 visitor->trace(m_parsedStyleSheetCache);
65 StyleSheetResource::trace(visitor);
66 }
67
didAddClient(ResourceClient * c)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
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 return decodedText();
92 }
93
checkNotify()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
isSafeToUnlock() const107 bool CSSStyleSheetResource::isSafeToUnlock() const
108 {
109 return m_data->hasOneRef();
110 }
111
destroyDecodedDataIfPossible()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
canUseSheet(bool enforceMIMEType,bool * hasValidMIMEType) const123 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
restoreParsedStyleSheet(const CSSParserContext & context)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
saveParsedStyleSheet(PassRefPtrWillBeRawPtr<StyleSheetContents> sheet)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