qt6-bb10/src/corelib/text/qstringconverter.h

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/****************************************************************************
**
** Copyright (C) 2020 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
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** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
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** Alternatively, this file may be used under the terms of the GNU
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****************************************************************************/
#ifndef QSTRINGCONVERTER_H
#define QSTRINGCONVERTER_H
#include <QtCore/qstring.h>
#if defined(QT_USE_FAST_OPERATOR_PLUS) || defined(QT_USE_QSTRINGBUILDER)
#include <QtCore/qstringbuilder.h>
#endif
#include <optional>
QT_BEGIN_NAMESPACE
// work around a compiler bug in GCC 7
#if (defined(Q_CC_GNU) && __GNUC__ == 7) || defined(Q_QDOC)
#define QSTRINGCONVERTER_CONSTEXPR
#else
#define QSTRINGCONVERTER_CONSTEXPR constexpr
#endif
class QStringConverterBase
{
public:
enum class Flag {
Default = 0,
Stateless = 0x1,
ConvertInvalidToNull = 0x2,
WriteBom = 0x4,
ConvertInitialBom = 0x8
};
Q_DECLARE_FLAGS(Flags, Flag)
struct State {
constexpr State(Flags f = Flag::Default)
: flags(f), state_data{0, 0, 0, 0} {}
~State() { clear(); }
State(State &&other)
: flags(other.flags),
remainingChars(other.remainingChars),
invalidChars(other.invalidChars),
d{other.d[0], other.d[1]},
clearFn(other.clearFn)
{ other.clearFn = nullptr; }
State &operator=(State &&other)
{
clear();
flags = other.flags;
remainingChars = other.remainingChars;
invalidChars = other.invalidChars;
d[0] = other.d[0];
d[1] = other.d[1];
clearFn = other.clearFn;
other.clearFn = nullptr;
return *this;
}
Q_CORE_EXPORT void clear();
Flags flags;
int internalState = 0;
qsizetype remainingChars = 0;
qsizetype invalidChars = 0;
union {
uint state_data[4];
void *d[2];
};
using ClearDataFn = void (*)(State *);
ClearDataFn clearFn = nullptr;
private:
Q_DISABLE_COPY(State)
};
};
Q_DECLARE_OPERATORS_FOR_FLAGS(QStringConverterBase::Flags)
class QStringConverter : public QStringConverterBase
{
public:
enum Encoding {
Utf8,
Utf16,
Utf16LE,
Utf16BE,
Utf32,
Utf32LE,
Utf32BE,
Latin1,
System,
LastEncoding = System
};
#ifdef Q_QDOC
// document the flags here
enum class Flag {
Default = 0,
Stateless = 0x1,
ConvertInvalidToNull = 0x2,
WriteBom = 0x4,
ConvertInitialBom = 0x8
};
Q_DECLARE_FLAGS(Flags, Flag)
#endif
protected:
struct Interface
{
using DecoderFn = QChar * (*)(QChar *out, QByteArrayView in, State *state);
using LengthFn = qsizetype (*)(qsizetype inLength);
using EncoderFn = char * (*)(char *out, QStringView in, State *state);
const char *name = nullptr;
DecoderFn toUtf16 = nullptr;
LengthFn toUtf16Len = nullptr;
EncoderFn fromUtf16 = nullptr;
LengthFn fromUtf16Len = nullptr;
};
QSTRINGCONVERTER_CONSTEXPR QStringConverter()
: iface(nullptr)
{}
QSTRINGCONVERTER_CONSTEXPR QStringConverter(Encoding encoding, Flags f)
: iface(&encodingInterfaces[int(encoding)]), state(f)
{}
QSTRINGCONVERTER_CONSTEXPR QStringConverter(const Interface *i)
: iface(i)
{}
Q_CORE_EXPORT QStringConverter(const char *name, Flags f);
public:
bool isValid() const { return iface != nullptr; }
void resetState()
{
state.clear();
}
bool hasError() const { return state.invalidChars != 0; }
const char *name() const
{ return isValid() ? iface->name : nullptr; }
Q_CORE_EXPORT static std::optional<Encoding> encodingForName(const char *name);
Q_CORE_EXPORT static const char *nameForEncoding(Encoding e);
Q_CORE_EXPORT static std::optional<Encoding> encodingForData(QByteArrayView data, char16_t expectedFirstCharacter = 0);
Q_CORE_EXPORT static std::optional<Encoding> encodingForHtml(QByteArrayView data);
protected:
const Interface *iface;
State state;
private:
Q_CORE_EXPORT static const Interface encodingInterfaces[Encoding::LastEncoding + 1];
};
class QStringEncoder : public QStringConverter
{
protected:
QSTRINGCONVERTER_CONSTEXPR QStringEncoder(const Interface *i)
: QStringConverter(i)
{}
public:
QSTRINGCONVERTER_CONSTEXPR QStringEncoder()
: QStringConverter()
{}
QSTRINGCONVERTER_CONSTEXPR QStringEncoder(Encoding encoding, Flags flags = Flag::Default)
: QStringConverter(encoding, flags)
{}
QStringEncoder(const char *name, Flags flags = Flag::Default)
: QStringConverter(name, flags)
{}
#if defined(Q_QDOC)
QByteArray operator()(const QString &in);
QByteArray operator()(QStringView in);
QByteArray encode(const QString &in);
QByteArray encode(QStringView in);
#else
template<typename T>
struct DecodedData
{
QStringEncoder *encoder;
T data;
operator QByteArray() const { return encoder->encodeAsByteArray(data); }
};
Q_WEAK_OVERLOAD
DecodedData<const QString &> operator()(const QString &str)
{ return DecodedData<const QString &>{this, str}; }
DecodedData<QStringView> operator()(QStringView in)
{ return DecodedData<QStringView>{this, in}; }
Q_WEAK_OVERLOAD
DecodedData<const QString &> encode(const QString &str)
{ return DecodedData<const QString &>{this, str}; }
DecodedData<QStringView> encode(QStringView in)
{ return DecodedData<QStringView>{this, in}; }
#endif
qsizetype requiredSpace(qsizetype inputLength) const
{ return iface->fromUtf16Len(inputLength); }
char *appendToBuffer(char *out, QStringView in)
{ return iface->fromUtf16(out, in, &state); }
private:
QByteArray encodeAsByteArray(QStringView in)
{
QByteArray result(iface->fromUtf16Len(in.size()), Qt::Uninitialized);
char *out = result.data();
out = iface->fromUtf16(out, in, &state);
result.truncate(out - result.constData());
return result;
}
};
class QStringDecoder : public QStringConverter
{
protected:
QSTRINGCONVERTER_CONSTEXPR QStringDecoder(const Interface *i)
: QStringConverter(i)
{}
public:
QSTRINGCONVERTER_CONSTEXPR QStringDecoder(Encoding encoding, Flags flags = Flag::Default)
: QStringConverter(encoding, flags)
{}
QSTRINGCONVERTER_CONSTEXPR QStringDecoder()
: QStringConverter()
{}
QStringDecoder(const char *name, Flags f = Flag::Default)
: QStringConverter(name, f)
{}
#if defined(Q_QDOC)
QString operator()(const QByteArray &ba);
QString operator()(QByteArrayView ba);
QString decode(const QByteArray &ba);
QString decode(QByteArrayView ba);
#else
template<typename T>
struct EncodedData
{
QStringDecoder *decoder;
T data;
operator QString() const { return decoder->decodeAsString(data); }
};
Q_WEAK_OVERLOAD
EncodedData<const QByteArray &> operator()(const QByteArray &ba)
{ return EncodedData<const QByteArray &>{this, ba}; }
EncodedData<QByteArrayView> operator()(QByteArrayView ba)
{ return EncodedData<QByteArrayView>{this, ba}; }
Q_WEAK_OVERLOAD
EncodedData<const QByteArray &> decode(const QByteArray &ba)
{ return EncodedData<const QByteArray &>{this, ba}; }
EncodedData<QByteArrayView> decode(QByteArrayView ba)
{ return EncodedData<QByteArrayView>{this, ba}; }
#endif
qsizetype requiredSpace(qsizetype inputLength) const
{ return iface->toUtf16Len(inputLength); }
QChar *appendToBuffer(QChar *out, QByteArrayView ba)
{ return iface->toUtf16(out, ba, &state); }
private:
QString decodeAsString(QByteArrayView in)
{
QString result(iface->toUtf16Len(in.size()), Qt::Uninitialized);
const QChar *out = iface->toUtf16(result.data(), in, &state);
result.truncate(out - result.constData());
return result;
}
};
#if defined(QT_USE_FAST_OPERATOR_PLUS) || defined(QT_USE_QSTRINGBUILDER)
template <typename T>
struct QConcatenable<QStringDecoder::EncodedData<T>>
: private QAbstractConcatenable
{
typedef QChar type;
typedef QString ConvertTo;
enum { ExactSize = false };
static qsizetype size(const QStringDecoder::EncodedData<T> &s) { return s.decoder->requiredSpace(s.data.size()); }
static inline void appendTo(const QStringDecoder::EncodedData<T> &s, QChar *&out)
{
out = s.decoder->appendToBuffer(out, s.data);
}
};
template <typename T>
struct QConcatenable<QStringEncoder::DecodedData<T>>
: private QAbstractConcatenable
{
typedef char type;
typedef QByteArray ConvertTo;
enum { ExactSize = false };
static qsizetype size(const QStringEncoder::DecodedData<T> &s) { return s.encoder->requiredSpace(s.data.size()); }
static inline void appendTo(const QStringEncoder::DecodedData<T> &s, char *&out)
{
out = s.encoder->appendToBuffer(out, s.data);
}
};
template <typename T>
QString &operator+=(QString &a, const QStringDecoder::EncodedData<T> &b)
{
qsizetype len = a.size() + QConcatenable<QStringDecoder::EncodedData<T>>::size(b);
a.reserve(len);
QChar *it = a.data() + a.size();
QConcatenable<QStringDecoder::EncodedData<T>>::appendTo(b, it);
a.resize(qsizetype(it - a.constData())); //may be smaller than len
return a;
}
template <typename T>
QByteArray &operator+=(QByteArray &a, const QStringEncoder::DecodedData<T> &b)
{
qsizetype len = a.size() + QConcatenable<QStringEncoder::DecodedData<T>>::size(b);
a.reserve(len);
char *it = a.data() + a.size();
QConcatenable<QStringEncoder::DecodedData<T>>::appendTo(b, it);
a.resize(qsizetype(it - a.constData())); //may be smaller than len
return a;
}
#endif
QT_END_NAMESPACE
#undef QSTRINGCONVERTER_CONSTEXPR
#endif