third_party/WebKit/Source/core/html/parser/CSSPreloadScanner.cpp

   1 /*
   2  * Copyright (C) 2008, 2010 Apple Inc. All Rights Reserved.
   3  * Copyright (C) 2009 Torch Mobile, Inc. http://www.torchmobile.com/
   4  * Copyright (C) 2010 Google Inc. All Rights Reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  16  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  22  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  23  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  25  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include "config.h"
  29 #include "core/html/parser/CSSPreloadScanner.h"
  30
  31 #include "core/fetch/FetchInitiatorTypeNames.h"
  32 #include "core/html/parser/HTMLParserIdioms.h"
  33 #include "platform/text/SegmentedString.h"
  34
  35 namespace blink {
  36
  37 CSSPreloadScanner::CSSPreloadScanner()
  38     : m_state(Initial)
  39     , m_requests(0)
  40     , m_referrerPolicy(ReferrerPolicyDefault)
  41 {
  42 }
  43
  44 CSSPreloadScanner::~CSSPreloadScanner()
  45 {
  46 }
  47
  48 void CSSPreloadScanner::reset()
  49 {
  50     m_state = Initial;
  51     m_rule.clear();
  52     m_ruleValue.clear();
  53 }
  54
  55 template<typename Char>
  56 void CSSPreloadScanner::scanCommon(const Char* begin, const Char* end, const SegmentedString& source, PreloadRequestStream& requests)
  57 {
  58     m_requests = &requests;
  59     for (const Char* it = begin; it != end && m_state != DoneParsingImportRules; ++it)
  60         tokenize(*it, source);
  61     m_requests = 0;
  62 }
  63
  64 void CSSPreloadScanner::scan(const HTMLToken::DataVector& data, const SegmentedString& source, PreloadRequestStream& requests)
  65 {
  66     scanCommon(data.data(), data.data() + data.size(), source, requests);
  67 }
  68
  69 void CSSPreloadScanner::scan(const String& tagName,  const SegmentedString& source, PreloadRequestStream& requests)
  70 {
  71     if (tagName.is8Bit()) {
  72         const LChar* begin = tagName.characters8();
  73         scanCommon(begin, begin + tagName.length(), source, requests);
  74         return;
  75     }
  76     const UChar* begin = tagName.characters16();
  77     scanCommon(begin, begin + tagName.length(), source, requests);
  78 }
  79
  80 void CSSPreloadScanner::setReferrerPolicy(const ReferrerPolicy policy)
  81 {
  82     m_referrerPolicy = policy;
  83 }
  84
  85 inline void CSSPreloadScanner::tokenize(UChar c, const SegmentedString& source)
  86 {
  87     // We are just interested in @import rules, no need for real tokenization here
  88     // Searching for other types of resources is probably low payoff.
  89     switch (m_state) {
  90     case Initial:
  91         if (isHTMLSpace<UChar>(c))
  92             break;
  93         if (c == '@')
  94             m_state = RuleStart;
  95         else if (c == '/')
  96             m_state = MaybeComment;
  97         else
  98             m_state = DoneParsingImportRules;
  99         break;
 100     case MaybeComment:
 101         if (c == '*')
 102             m_state = Comment;
 103         else
 104             m_state = Initial;
 105         break;
 106     case Comment:
 107         if (c == '*')
 108             m_state = MaybeCommentEnd;
 109         break;
 110     case MaybeCommentEnd:
 111         if (c == '*')
 112             break;
 113         if (c == '/')
 114             m_state = Initial;
 115         else
 116             m_state = Comment;
 117         break;
 118     case RuleStart:
 119         if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')) {
 120             m_rule.clear();
 121             m_ruleValue.clear();
 122             m_rule.append(c);
 123             m_state = Rule;
 124         } else
 125             m_state = Initial;
 126         break;
 127     case Rule:
 128         if (isHTMLSpace<UChar>(c))
 129             m_state = AfterRule;
 130         else if (c == ';')
 131             m_state = Initial;
 132         else
 133             m_rule.append(c);
 134         break;
 135     case AfterRule:
 136         if (isHTMLSpace<UChar>(c))
 137             break;
 138         if (c == ';')
 139             m_state = Initial;
 140         else if (c == '{')
 141             m_state = DoneParsingImportRules;
 142         else {
 143             m_state = RuleValue;
 144             m_ruleValue.append(c);
 145         }
 146         break;
 147     case RuleValue:
 148         if (isHTMLSpace<UChar>(c))
 149             m_state = AfterRuleValue;
 150         else if (c == ';')
 151             emitRule(source);
 152         else
 153             m_ruleValue.append(c);
 154         break;
 155     case AfterRuleValue:
 156         if (isHTMLSpace<UChar>(c))
 157             break;
 158         if (c == ';')
 159             emitRule(source);
 160         else if (c == '{')
 161             m_state = DoneParsingImportRules;
 162         else {
 163             // FIXME: media rules
 164             m_state = Initial;
 165         }
 166         break;
 167     case DoneParsingImportRules:
 168         ASSERT_NOT_REACHED();
 169         break;
 170     }
 171 }
 172
 173 static String parseCSSStringOrURL(const String& string)
 174 {
 175     size_t offset = 0;
 176     size_t reducedLength = string.length();
 177
 178     while (reducedLength && isHTMLSpace<UChar>(string[offset])) {
 179         ++offset;
 180         --reducedLength;
 181     }
 182     while (reducedLength && isHTMLSpace<UChar>(string[offset + reducedLength - 1]))
 183         --reducedLength;
 184
 185     if (reducedLength >= 5
 186         && (string[offset] == 'u' || string[offset] == 'U')
 187         && (string[offset + 1] == 'r' || string[offset + 1] == 'R')
 188         && (string[offset + 2] == 'l' || string[offset + 2] == 'L')
 189         && string[offset + 3] == '('
 190         && string[offset + reducedLength - 1] == ')') {
 191         offset += 4;
 192         reducedLength -= 5;
 193     }
 194
 195     while (reducedLength && isHTMLSpace<UChar>(string[offset])) {
 196         ++offset;
 197         --reducedLength;
 198     }
 199     while (reducedLength && isHTMLSpace<UChar>(string[offset + reducedLength - 1]))
 200         --reducedLength;
 201
 202     if (reducedLength < 2 || string[offset] != string[offset + reducedLength - 1] || !(string[offset] == '\'' || string[offset] == '"'))
 203         return String();
 204     offset++;
 205     reducedLength -= 2;
 206
 207     while (reducedLength && isHTMLSpace<UChar>(string[offset])) {
 208         ++offset;
 209         --reducedLength;
 210     }
 211     while (reducedLength && isHTMLSpace<UChar>(string[offset + reducedLength - 1]))
 212         --reducedLength;
 213
 214     return string.substring(offset, reducedLength);
 215 }
 216
 217 void CSSPreloadScanner::emitRule(const SegmentedString& source)
 218 {
 219     if (equalIgnoringCase(m_rule, "import")) {
 220         String url = parseCSSStringOrURL(m_ruleValue.toString());
 221         if (!url.isEmpty()) {
 222             KURL baseElementURL; // FIXME: This should be passed in from the HTMLPreloadScaner via scan()!
 223             TextPosition position = TextPosition(source.currentLine(), source.currentColumn());
 224             OwnPtr<PreloadRequest> request = PreloadRequest::create(FetchInitiatorTypeNames::css, position, url, baseElementURL, Resource::CSSStyleSheet, m_referrerPolicy);
 225             // FIXME: Should this be including the charset in the preload request?
 226             m_requests->append(request.release());
 227         }
 228         m_state = Initial;
 229     } else if (equalIgnoringCase(m_rule, "charset"))
 230         m_state = Initial;
 231     else
 232         m_state = DoneParsingImportRules;
 233     m_rule.clear();
 234     m_ruleValue.clear();
 235 }
 236
 237 }