bool TextEncoding::isNonByteBasedEncoding() const
{
if (noExtendedTextEncodingNameUsed()) {
return *this == UTF16LittleEndianEncoding()
|| *this == UTF16BigEndianEncoding();
}
return *this == UTF16LittleEndianEncoding()
|| *this == UTF16BigEndianEncoding()
|| *this == UTF32BigEndianEncoding()
|| *this == UTF32LittleEndianEncoding();
}
String TextDecoder::checkForBOM(const char* data, size_t length, bool flush, bool stopOnError, bool& sawError)
{
ASSERT(!m_checkedForBOM);
// Check to see if we found a BOM.
size_t numBufferedBytes = m_numBufferedBytes;
size_t buf1Len = numBufferedBytes;
size_t buf2Len = length;
const unsigned char* buf1 = m_bufferedBytes;
const unsigned char* buf2 = reinterpret_cast<const unsigned char*>(data);
unsigned char c1 = buf1Len ? (--buf1Len, *buf1++) : buf2Len ? (--buf2Len, *buf2++) : 0;
unsigned char c2 = buf1Len ? (--buf1Len, *buf1++) : buf2Len ? (--buf2Len, *buf2++) : 0;
unsigned char c3 = buf1Len ? (--buf1Len, *buf1++) : buf2Len ? (--buf2Len, *buf2++) : 0;
unsigned char c4 = buf2Len ? (--buf2Len, *buf2++) : 0;
const TextEncoding* encodingConsideringBOM = &m_encoding;
bool foundBOM = true;
size_t lengthOfBOM = 0;
if (c1 == 0xFF && c2 == 0xFE) {
if (c3 != 0 || c4 != 0) {
encodingConsideringBOM = &UTF16LittleEndianEncoding();
lengthOfBOM = 2;
} else if (numBufferedBytes + length > sizeof(m_bufferedBytes)) {
encodingConsideringBOM = &UTF32LittleEndianEncoding();
lengthOfBOM = 4;
} else
foundBOM = false;
} else if (c1 == 0xEF && c2 == 0xBB && c3 == 0xBF) {
encodingConsideringBOM = &UTF8Encoding();
lengthOfBOM = 3;
} else if (c1 == 0xFE && c2 == 0xFF) {
encodingConsideringBOM = &UTF16BigEndianEncoding();
lengthOfBOM = 2;
} else if (c1 == 0 && c2 == 0 && c3 == 0xFE && c4 == 0xFF) {
encodingConsideringBOM = &UTF32BigEndianEncoding();
lengthOfBOM = 4;
} else
foundBOM = false;
if (!foundBOM && numBufferedBytes + length <= sizeof(m_bufferedBytes) && !flush) {
// Continue to look for the BOM.
memcpy(&m_bufferedBytes[numBufferedBytes], data, length);
m_numBufferedBytes += length;
return "";
}
// Done checking for BOM.
m_codec.set(newTextCodec(*encodingConsideringBOM).release());
if (!m_codec)
return String();
m_checkedForBOM = true;
// Skip the BOM.
if (foundBOM) {
ASSERT(numBufferedBytes < lengthOfBOM);
size_t numUnbufferedBOMBytes = lengthOfBOM - numBufferedBytes;
ASSERT(numUnbufferedBOMBytes <= length);
data += numUnbufferedBOMBytes;
length -= numUnbufferedBOMBytes;
numBufferedBytes = 0;
m_numBufferedBytes = 0;
}
// Handle case where we have some buffered bytes to deal with.
if (numBufferedBytes) {
char bufferedBytes[sizeof(m_bufferedBytes)];
memcpy(bufferedBytes, m_bufferedBytes, numBufferedBytes);
m_numBufferedBytes = 0;
String bufferedResult = m_codec->decode(bufferedBytes, numBufferedBytes, false, stopOnError, sawError);
if (stopOnError && sawError)
return bufferedResult;
return bufferedResult + m_codec->decode(data, length, flush, stopOnError, sawError);
}
return m_codec->decode(data, length, flush, stopOnError, sawError);
}
