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/*
* Copyright (C) 2008, 2010, 2013, 2014 Apple Inc. All Rights Reserved.
* Copyright (C) 2009 Torch Mobile, Inc. http://www.torchmobile.com/
* Copyright (C) 2010 Google Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "CSSPreloadScanner.h"
#include "HTMLParserIdioms.h"
#include <wtf/SetForScope.h>
namespace WebCore {
CSSPreloadScanner::CSSPreloadScanner()
: m_state(Initial)
, m_requests(nullptr)
{
}
CSSPreloadScanner::~CSSPreloadScanner() = default;
void CSSPreloadScanner::reset()
{
m_state = Initial;
m_rule.clear();
m_ruleValue.clear();
}
void CSSPreloadScanner::scan(const HTMLToken::DataVector& data, PreloadRequestStream& requests)
{
ASSERT(!m_requests);
SetForScope<PreloadRequestStream*> change(m_requests, &requests);
for (UChar c : data) {
if (m_state == DoneParsingImportRules)
break;
tokenize(c);
}
}
inline void CSSPreloadScanner::tokenize(UChar c)
{
// We are just interested in @import rules, no need for real tokenization here
// Searching for other types of resources is probably low payoff.
switch (m_state) {
case Initial:
if (isHTMLSpace(c))
break;
if (c == '@')
m_state = RuleStart;
else if (c == '/')
m_state = MaybeComment;
else
m_state = DoneParsingImportRules;
break;
case MaybeComment:
if (c == '*')
m_state = Comment;
else
m_state = Initial;
break;
case Comment:
if (c == '*')
m_state = MaybeCommentEnd;
break;
case MaybeCommentEnd:
if (c == '*')
break;
if (c == '/')
m_state = Initial;
else
m_state = Comment;
break;
case RuleStart:
if (isASCIIAlpha(c)) {
m_rule.clear();
m_ruleValue.clear();
m_rule.append(c);
m_state = Rule;
} else
m_state = Initial;
break;
case Rule:
if (isHTMLSpace(c))
m_state = AfterRule;
else if (c == ';')
m_state = Initial;
else
m_rule.append(c);
break;
case AfterRule:
if (isHTMLSpace(c))
break;
if (c == ';')
m_state = Initial;
else if (c == '{')
m_state = DoneParsingImportRules;
else {
m_state = RuleValue;
m_ruleValue.append(c);
}
break;
case RuleValue:
if (isHTMLSpace(c))
m_state = AfterRuleValue;
else if (c == ';')
emitRule();
else
m_ruleValue.append(c);
break;
case AfterRuleValue:
if (isHTMLSpace(c))
break;
if (c == ';')
emitRule();
else if (c == '{')
m_state = DoneParsingImportRules;
else {
// FIXME: media rules
m_state = Initial;
}
break;
case DoneParsingImportRules:
ASSERT_NOT_REACHED();
break;
}
}
static String parseCSSStringOrURL(const UChar* characters, size_t length)
{
size_t offset = 0;
size_t reducedLength = length;
while (reducedLength && isHTMLSpace(characters[offset])) {
++offset;
--reducedLength;
}
while (reducedLength && isHTMLSpace(characters[offset + reducedLength - 1]))
--reducedLength;
if (reducedLength >= 5
&& (characters[offset] == 'u' || characters[offset] == 'U')
&& (characters[offset + 1] == 'r' || characters[offset + 1] == 'R')
&& (characters[offset + 2] == 'l' || characters[offset + 2] == 'L')
&& characters[offset + 3] == '('
&& characters[offset + reducedLength - 1] == ')') {
offset += 4;
reducedLength -= 5;
}
while (reducedLength && isHTMLSpace(characters[offset])) {
++offset;
--reducedLength;
}
while (reducedLength && isHTMLSpace(characters[offset + reducedLength - 1]))
--reducedLength;
if (reducedLength < 2 || characters[offset] != characters[offset + reducedLength - 1] || !(characters[offset] == '\'' || characters[offset] == '"'))
return String();
offset++;
reducedLength -= 2;
while (reducedLength && isHTMLSpace(characters[offset])) {
++offset;
--reducedLength;
}
while (reducedLength && isHTMLSpace(characters[offset + reducedLength - 1]))
--reducedLength;
return String(characters + offset, reducedLength);
}
void CSSPreloadScanner::emitRule()
{
StringView rule(m_rule.data(), m_rule.size());
if (equalLettersIgnoringASCIICase(rule, "import")) {
String url = parseCSSStringOrURL(m_ruleValue.data(), m_ruleValue.size());
if (!url.isEmpty()) {
URL baseElementURL; // FIXME: This should be passed in from the HTMLPreloadScanner via scan(): without it we will get relative URLs wrong.
// FIXME: Should this be including the charset in the preload request?
m_requests->append(std::make_unique<PreloadRequest>("css", url, baseElementURL, CachedResource::Type::CSSStyleSheet, String(), PreloadRequest::ModuleScript::No));
}
m_state = Initial;
} else if (equalLettersIgnoringASCIICase(rule, "charset"))
m_state = Initial;
else
m_state = DoneParsingImportRules;
m_rule.clear();
m_ruleValue.clear();
}
}