Optimize QXmlStreamWriterPrivate::doWriteToDevice(QLatin1StringView)

Use a stack buffer, and perform the recoding from L1 to U8 in chunks.

Solves the L1 case of

Task-number: QTBUG-109284
Pick-to: 6.5
Change-Id: Ia9ac7d8b27fd452d24d9e27f0575f9fc83b6dcbc
Reviewed-by: Mate Barany <mate.barany@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
This commit is contained in:
Marc Mutz 2022-12-08 16:10:06 +01:00
parent 2ae75c2e6a
commit e3f230e7be

View File

@ -3085,10 +3085,14 @@ void QXmlStreamWriterPrivate::doWriteToDevice(QUtf8StringView s)
void QXmlStreamWriterPrivate::doWriteToDevice(QLatin1StringView s)
{
QByteArray utf8(s.size() * 2, Qt::Uninitialized);
char *end = QUtf8::convertFromLatin1(utf8.data(), s);
utf8.truncate(end - utf8.data());
doWriteToDevice(QUtf8StringView{utf8});
constexpr qsizetype MaxChunkSize = 512;
char buffer [2 * MaxChunkSize];
while (!s.isEmpty()) {
const qsizetype chunkSize = std::min(s.size(), MaxChunkSize);
char *end = QUtf8::convertFromLatin1(buffer, s.first(chunkSize));
doWriteToDevice(QUtf8StringView{buffer, end});
s = s.sliced(chunkSize);
}
}
/*!