CSSPreloadScanner.cpp [plain text]
#include "config.h"
#include "CSSPreloadScanner.h"
#include "CachedResourceRequestInitiators.h"
#include "HTMLIdentifier.h"
#include "HTMLParserIdioms.h"
namespace WebCore {
CSSPreloadScanner::CSSPreloadScanner()
: m_state(Initial)
, m_requests(0)
{
}
CSSPreloadScanner::~CSSPreloadScanner()
{
}
void CSSPreloadScanner::reset()
{
m_state = Initial;
m_rule.clear();
m_ruleValue.clear();
}
template<typename Char>
void CSSPreloadScanner::scanCommon(const Char* begin, const Char* end, PreloadRequestStream& requests)
{
m_requests = &requests;
for (const Char* it = begin; it != end && m_state != DoneParsingImportRules; ++it)
tokenize(*it);
m_requests = 0;
}
void CSSPreloadScanner::scan(const HTMLToken::DataVector& data, PreloadRequestStream& requests)
{
scanCommon(data.data(), data.data() + data.size(), requests);
}
#if ENABLE(THREADED_HTML_PARSER)
void CSSPreloadScanner::scan(const HTMLIdentifier& identifier, PreloadRequestStream& requests)
{
const StringImpl* data = identifier.asStringImpl();
if (data->is8Bit()) {
const LChar* begin = data->characters8();
scanCommon(begin, begin + data->length(), requests);
return;
}
const UChar* begin = data->characters16();
scanCommon(begin, begin + data->length(), requests);
}
#endif
inline void CSSPreloadScanner::tokenize(UChar c)
{
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 ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')) {
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 {
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);
}
template<unsigned referenceLength>
static inline bool ruleEqualIgnoringCase(const Vector<UChar>& rule, const char (&reference)[referenceLength])
{
unsigned referenceCharactersLength = referenceLength - 1;
return rule.size() == referenceCharactersLength && equalIgnoringCase(reference, rule.data(), referenceCharactersLength);
}
void CSSPreloadScanner::emitRule()
{
if (ruleEqualIgnoringCase(m_rule, "import")) {
String url = parseCSSStringOrURL(m_ruleValue.data(), m_ruleValue.size());
if (!url.isEmpty()) {
KURL baseElementURL; OwnPtr<PreloadRequest> request = PreloadRequest::create("css", url, baseElementURL, CachedResource::CSSStyleSheet);
m_requests->append(request.release());
}
m_state = Initial;
} else if (ruleEqualIgnoringCase(m_rule, "charset"))
m_state = Initial;
else
m_state = DoneParsingImportRules;
m_rule.clear();
m_ruleValue.clear();
}
}