AuroraMiddleware/qt5base-lts
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Refactor QUtf32::convertFromUnicode

Browse Source 
Implement proper state handling, and avoid a copy when using
it through QStringConverter.

Change-Id: I201fe966601c424c337e452e359a2e71f76354ad
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
This commit is contained in:
Lars Knoll 2020-04-23 12:38:00 +02:00
parent d8997ad797
commit b1d8ce32cd
2 changed files with 69 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

112
src/corelib/text/qstringconverter.cpp
View File

@ -898,11 +898,22 @@ QChar *QUtf16::convertToUnicode(QChar *out, const char *chars, qsizetype len, QS
QByteArray QUtf32::convertFromUnicode(const QChar *uc, qsizetype len, QStringConverter::State *state, DataEndianness endian)
{
Q_ASSERT(state);
if (state->flags & QStringConverter::Flag::Stateless) // temporary
state = nullptr;
bool writeBom = !(state->internalState & HeaderDone) && state->flags & QStringConverter::Flag::WriteBom;
int length = 4*len;
if (writeBom)
length += 4;
QByteArray ba(length, Qt::Uninitialized);
char *end = convertFromUnicode(ba.data(), uc, len, state, endian);
Q_ASSERT(end - ba.constData() == length);
Q_UNUSED(end);
return ba;
}
bool writeBom = state && !(state->internalState & HeaderDone) && state->flags & QStringConverter::Flag::WriteBom;
char *QUtf32::convertFromUnicode(char *out, const QChar *uc, qsizetype len, QStringConverter::State *state, DataEndianness endian)
{
Q_ASSERT(state);
bool writeBom = !(state->internalState & HeaderDone) && state->flags & QStringConverter::Flag::WriteBom;
qsizetype length = 4*len;
if (writeBom)
length += 4;
@ -910,43 +921,62 @@ QByteArray QUtf32::convertFromUnicode(const QChar *uc, qsizetype len, QStringCon
if (endian == DetectEndianness)
endian = (QSysInfo::ByteOrder == QSysInfo::BigEndian) ? BigEndianness : LittleEndianness;
QByteArray d(length, Qt::Uninitialized);
char *data = d.data();
if (writeBom) {
if (endian == BigEndianness) {
data[0] = 0;
data[1] = 0;
data[2] = (char)0xfe;
data[3] = (char)0xff;
out[0] = 0;
out[1] = 0;
out[2] = (char)0xfe;
out[3] = (char)0xff;
} else {
data[0] = (char)0xff;
data[1] = (char)0xfe;
data[2] = 0;
data[3] = 0;
out[0] = (char)0xff;
out[1] = (char)0xfe;
out[2] = 0;
out[3] = 0;
}
data += 4;
}
QStringIterator i(uc, uc + len);
if (endian == BigEndianness) {
while (i.hasNext()) {
uint cp = i.next();
qToBigEndian(cp, data);
data += 4;
}
} else {
while (i.hasNext()) {
uint cp = i.next();
qToLittleEndian(cp, data);
data += 4;
}
}
if (state) {
state->remainingChars = 0;
out += 4;
state->internalState |= HeaderDone;
}
return d;
const QChar *end = uc + len;
QChar ch;
uint ucs4;
if (state->remainingChars == 1) {
ch = state->state_data[Data];
// this is ugly, but shortcuts a whole lot of logic that would otherwise be required
state->remainingChars = 0;
goto decode_surrogate;
}
while (uc < end) {
ch = *uc++;
if (Q_LIKELY(!ch.isSurrogate())) {
ucs4 = ch.unicode();
} else if (Q_LIKELY(ch.isHighSurrogate())) {
decode_surrogate:
if (uc == end) {
if (state->flags & QStringConverter::Flag::Stateless) {
ucs4 = state->flags & QStringConverter::Flag::ConvertInvalidToNull ? 0 : QChar::ReplacementCharacter;
} else {
state->remainingChars = 1;
state->state_data[Data] = ch.unicode();
return out;
}
} else if (uc->isLowSurrogate()) {
ucs4 = QChar::surrogateToUcs4(ch, *uc++);
} else {
ucs4 = state->flags & QStringConverter::Flag::ConvertInvalidToNull ? 0 : QChar::ReplacementCharacter;
}
} else {
ucs4 = state->flags & QStringConverter::Flag::ConvertInvalidToNull ? 0 : QChar::ReplacementCharacter;
}
if (endian == BigEndianness)
qToBigEndian(ucs4, out);
else
qToLittleEndian(ucs4, out);
out += 4;
}
return out;
}
QString QUtf32::convertToUnicode(const char *chars, qsizetype len, QStringConverter::State *state, DataEndianness endian)
@ -1299,9 +1329,7 @@ static QChar *fromUtf32(QChar *out, const char *in, qsizetype length, QStringCon
static char *toUtf32(char *out, QStringView in, QStringConverter::State *state)
{
QByteArray s = QUtf32::convertFromUnicode(in.data(), in.length(), state);
memcpy(out, s.constData(), s.length());
return out + s.length();
return QUtf32::convertFromUnicode(out, in.data(), in.length(), state, DetectEndianness);
}
static QChar *fromUtf32BE(QChar *out, const char *in, qsizetype length, QStringConverter::State *state)
@ -1313,9 +1341,7 @@ static QChar *fromUtf32BE(QChar *out, const char *in, qsizetype length, QStringC
static char *toUtf32BE(char *out, QStringView in, QStringConverter::State *state)
{
QByteArray s = QUtf32::convertFromUnicode(in.data(), in.length(), state, BigEndianness);
memcpy(out, s.constData(), s.length());
return out + s.length();
return QUtf32::convertFromUnicode(out, in.data(), in.length(), state, BigEndianness);
}
static QChar *fromUtf32LE(QChar *out, const char *in, qsizetype length, QStringConverter::State *state)
@ -1327,9 +1353,7 @@ static QChar *fromUtf32LE(QChar *out, const char *in, qsizetype length, QStringC
static char *toUtf32LE(char *out, QStringView in, QStringConverter::State *state)
{
QByteArray s = QUtf32::convertFromUnicode(in.data(), in.length(), state, LittleEndianness);
memcpy(out, s.constData(), s.length());
return out + s.length();
return QUtf32::convertFromUnicode(out, in.data(), in.length(), state, LittleEndianness);
}
void qt_from_latin1(char16_t *dst, const char *str, size_t size) noexcept;

1
src/corelib/text/qstringconverter_p.h
View File

@ -314,6 +314,7 @@ struct QUtf32
{
static QString convertToUnicode(const char *, qsizetype, QStringConverter::State *, DataEndianness = DetectEndianness);
static QByteArray convertFromUnicode(const QChar *, qsizetype, QStringConverter::State *, DataEndianness = DetectEndianness);
static char *convertFromUnicode(char *out, const QChar *uc, qsizetype len, QStringConverter::State *state, DataEndianness endian);
};
struct QLocal8Bit