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-rw-r--r--src/corelib/text/qstringbuilder.h228
1 files changed, 111 insertions, 117 deletions
diff --git a/src/corelib/text/qstringbuilder.h b/src/corelib/text/qstringbuilder.h
index 5a6a531e74..dfe9863b74 100644
--- a/src/corelib/text/qstringbuilder.h
+++ b/src/corelib/text/qstringbuilder.h
@@ -1,41 +1,7 @@
-/****************************************************************************
-**
-** 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.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
+// Copyright (C) 2020 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include <QtCore/qstring.h>
#ifndef QSTRINGBUILDER_H
#define QSTRINGBUILDER_H
@@ -47,7 +13,6 @@
#pragma qt_sync_stop_processing
#endif
-#include <QtCore/qstring.h>
#include <QtCore/qbytearray.h>
#include <string.h>
@@ -63,16 +28,28 @@ protected:
{
*out++ = QLatin1Char(a);
}
- static void appendLatin1To(QLatin1String in, QChar *out) noexcept;
+ static void appendLatin1To(QLatin1StringView in, QChar *out) noexcept;
};
-template <typename T> struct QConcatenable {};
+template <typename T> struct QConcatenable;
+
+template <typename T>
+using QConcatenableEx = QConcatenable<q20::remove_cvref_t<T>>;
namespace QtStringBuilder {
template <typename A, typename B> struct ConvertToTypeHelper
{ typedef A ConvertTo; };
template <typename T> struct ConvertToTypeHelper<T, QString>
{ typedef QString ConvertTo; };
+
+ template <typename T> using HasIsNull = decltype(std::declval<const T &>().isNull());
+ template <typename T> bool isNull(const T &t)
+ {
+ if constexpr (qxp::is_detected_v<HasIsNull, T>)
+ return t.isNull();
+ else
+ return false;
+ }
}
template<typename Builder, typename T>
@@ -99,25 +76,48 @@ struct QStringBuilderBase<Builder, QString> : public QStringBuilderCommon<Builde
};
template <typename A, typename B>
-class QStringBuilder : public QStringBuilderBase<QStringBuilder<A, B>, typename QtStringBuilder::ConvertToTypeHelper<typename QConcatenable<A>::ConvertTo, typename QConcatenable<B>::ConvertTo>::ConvertTo>
+class QStringBuilder : public QStringBuilderBase<QStringBuilder<A, B>,
+ typename QtStringBuilder::ConvertToTypeHelper<
+ typename QConcatenableEx<A>::ConvertTo,
+ typename QConcatenableEx<B>::ConvertTo
+ >::ConvertTo
+ >
{
public:
- QStringBuilder(const A &a_, const B &b_) : a(a_), b(b_) {}
+ QStringBuilder(A &&a_, B &&b_) : a(std::forward<A>(a_)), b(std::forward<B>(b_)) {}
+
+ QStringBuilder(QStringBuilder &&) = default;
+ QStringBuilder(const QStringBuilder &) = default;
+ ~QStringBuilder() = default;
+
private:
friend class QByteArray;
friend class QString;
template <typename T> T convertTo() const
{
+ if (isNull()) {
+ // appending two null strings must give back a null string,
+ // so we're special casing this one out, QTBUG-114206
+ return T();
+ }
+
const qsizetype len = QConcatenable< QStringBuilder<A, B> >::size(*this);
T s(len, Qt::Uninitialized);
- // we abuse const_cast / constData here because we know we've just
- // allocated the data and we're the only reference count
- typename T::iterator d = const_cast<typename T::iterator>(s.constData());
- typename T::const_iterator const start = d;
- QConcatenable< QStringBuilder<A, B> >::appendTo(*this, d);
+ // Using data_ptr() here (private API) so we can bypass the
+ // isDetached() and the replacement of a null pointer with _empty in
+ // both QString and QByteArray's data() and constData(). The result is
+ // the same if len != 0.
+ auto d = reinterpret_cast<typename T::iterator>(s.data_ptr().data());
- if (!QConcatenable< QStringBuilder<A, B> >::ExactSize && len != d - start) {
+ if constexpr (QConcatenable<QStringBuilder<A, B>>::ExactSize) {
+ QConcatenable<QStringBuilder<A, B>>::appendTo(*this, d);
+ return s;
+ }
+
+ typename T::const_iterator const start = d;
+ QConcatenable<QStringBuilder<A, B>>::appendTo(*this, d);
+ if (len != d - start) {
// this resize is necessary since we allocate a bit too much
// when dealing with variable sized 8-bit encodings
s.resize(d - start);
@@ -132,45 +132,19 @@ public:
qsizetype size() const { return Concatenable::size(*this); }
- const A &a;
- const B &b;
-};
-
-template <>
-class QStringBuilder <QString, QString> : public QStringBuilderBase<QStringBuilder<QString, QString>, QString>
-{
- public:
- QStringBuilder(const QString &a_, const QString &b_) : a(a_), b(b_) {}
- QStringBuilder(const QStringBuilder &other) : a(other.a), b(other.b) {}
-
- operator QString() const
- { QString r(a); r += b; return r; }
-
- const QString &a;
- const QString &b;
-
- private:
- QStringBuilder &operator=(const QStringBuilder &) = delete;
-};
-
-template <>
-class QStringBuilder <QByteArray, QByteArray> : public QStringBuilderBase<QStringBuilder<QByteArray, QByteArray>, QByteArray>
-{
- public:
- QStringBuilder(const QByteArray &a_, const QByteArray &b_) : a(a_), b(b_) {}
- QStringBuilder(const QStringBuilder &other) : a(other.a), b(other.b) {}
-
- operator QByteArray() const
- { QByteArray r(a); r += b; return r; }
+ bool isNull() const
+ {
+ return QtStringBuilder::isNull(a) && QtStringBuilder::isNull(b);
+ }
- const QByteArray &a;
- const QByteArray &b;
+ A a;
+ B b;
- private:
- QStringBuilder &operator=(const QStringBuilder &) = delete;
+private:
+ QStringBuilder &operator=(QStringBuilder &&) = delete;
+ QStringBuilder &operator=(const QStringBuilder &) = delete;
};
-
template <> struct QConcatenable<char> : private QAbstractConcatenable
{
typedef char type;
@@ -187,6 +161,27 @@ template <> struct QConcatenable<char> : private QAbstractConcatenable
{ *out++ = c; }
};
+template <> struct QConcatenable<QByteArrayView> : private QAbstractConcatenable
+{
+ typedef QByteArrayView type;
+ typedef QByteArray ConvertTo;
+ enum { ExactSize = true };
+ static qsizetype size(QByteArrayView bav) { return bav.size(); }
+#ifndef QT_NO_CAST_FROM_ASCII
+ QT_ASCII_CAST_WARN static inline void appendTo(QByteArrayView bav, QChar *&out)
+ {
+ QAbstractConcatenable::convertFromUtf8(bav, out);
+ }
+#endif
+ static inline void appendTo(QByteArrayView bav, char *&out)
+ {
+ qsizetype n = bav.size();
+ if (n)
+ memcpy(out, bav.data(), n);
+ out += n;
+ }
+};
+
template <> struct QConcatenable<char16_t> : private QAbstractConcatenable
{
typedef char16_t type;
@@ -229,18 +224,18 @@ template <> struct QConcatenable<QChar::SpecialCharacter> : private QAbstractCon
{ *out++ = c; }
};
-template <> struct QConcatenable<QLatin1String> : private QAbstractConcatenable
+template <> struct QConcatenable<QLatin1StringView> : private QAbstractConcatenable
{
- typedef QLatin1String type;
+ typedef QLatin1StringView type;
typedef QString ConvertTo;
enum { ExactSize = true };
- static qsizetype size(const QLatin1String a) { return a.size(); }
- static inline void appendTo(const QLatin1String a, QChar *&out)
+ static qsizetype size(const QLatin1StringView a) { return a.size(); }
+ static inline void appendTo(const QLatin1StringView a, QChar *&out)
{
appendLatin1To(a, out);
out += a.size();
}
- static inline void appendTo(const QLatin1String a, char *&out)
+ static inline void appendTo(const QLatin1StringView a, char *&out)
{
if (const char *data = a.data()) {
memcpy(out, data, a.size());
@@ -379,10 +374,10 @@ template <> struct QConcatenable<QByteArray> : private QAbstractConcatenable
#endif
static inline void appendTo(const QByteArray &ba, char *&out)
{
- const char *a = ba.constData();
- const char * const end = ba.end();
- while (a != end)
- *out++ = *a++;
+ const qsizetype n = ba.size();
+ if (n)
+ memcpy(out, ba.begin(), n);
+ out += n;
}
};
@@ -391,34 +386,37 @@ template <typename A, typename B>
struct QConcatenable< QStringBuilder<A, B> >
{
typedef QStringBuilder<A, B> type;
- typedef typename QtStringBuilder::ConvertToTypeHelper<typename QConcatenable<A>::ConvertTo, typename QConcatenable<B>::ConvertTo>::ConvertTo ConvertTo;
- enum { ExactSize = QConcatenable<A>::ExactSize && QConcatenable<B>::ExactSize };
+ using ConvertTo = typename QtStringBuilder::ConvertToTypeHelper<
+ typename QConcatenableEx<A>::ConvertTo,
+ typename QConcatenableEx<B>::ConvertTo
+ >::ConvertTo;
+ enum { ExactSize = QConcatenableEx<A>::ExactSize && QConcatenableEx<B>::ExactSize };
static qsizetype size(const type &p)
{
- return QConcatenable<A>::size(p.a) + QConcatenable<B>::size(p.b);
+ return QConcatenableEx<A>::size(p.a) + QConcatenableEx<B>::size(p.b);
}
template<typename T> static inline void appendTo(const type &p, T *&out)
{
- QConcatenable<A>::appendTo(p.a, out);
- QConcatenable<B>::appendTo(p.b, out);
+ QConcatenableEx<A>::appendTo(p.a, out);
+ QConcatenableEx<B>::appendTo(p.b, out);
}
};
-template <typename A, typename B>
-QStringBuilder<typename QConcatenable<A>::type, typename QConcatenable<B>::type>
-operator%(const A &a, const B &b)
+template <typename A, typename B,
+ typename = std::void_t<typename QConcatenableEx<A>::type, typename QConcatenableEx<B>::type>>
+auto operator%(A &&a, B &&b)
{
- return QStringBuilder<typename QConcatenable<A>::type, typename QConcatenable<B>::type>(a, b);
+ return QStringBuilder<A, B>(std::forward<A>(a), std::forward<B>(b));
}
// QT_USE_FAST_OPERATOR_PLUS was introduced in 4.7, QT_USE_QSTRINGBUILDER is to be used from 4.8 onwards
// QT_USE_FAST_OPERATOR_PLUS does not remove the normal operator+ for QByteArray
#if defined(QT_USE_FAST_OPERATOR_PLUS) || defined(QT_USE_QSTRINGBUILDER)
-template <typename A, typename B>
-QStringBuilder<typename QConcatenable<A>::type, typename QConcatenable<B>::type>
-operator+(const A &a, const B &b)
+template <typename A, typename B,
+ typename = std::void_t<typename QConcatenableEx<A>::type, typename QConcatenableEx<B>::type>>
+auto operator+(A &&a, B &&b)
{
- return QStringBuilder<typename QConcatenable<A>::type, typename QConcatenable<B>::type>(a, b);
+ return std::forward<A>(a) % std::forward<B>(b);
}
#endif
@@ -428,7 +426,9 @@ QByteArray &appendToByteArray(QByteArray &a, const QStringBuilder<A, B> &b, char
{
// append 8-bit data to a byte array
qsizetype len = a.size() + QConcatenable< QStringBuilder<A, B> >::size(b);
- a.reserve(len);
+ a.detach(); // a detach() in a.data() could reset a.capacity() to a.size()
+ if (len > a.data_ptr().freeSpaceAtEnd()) // capacity() was broken when prepend()-optimization landed
+ a.reserve(qMax(len, 2 * a.capacity()));
char *it = a.data() + a.size();
QConcatenable< QStringBuilder<A, B> >::appendTo(b, it);
a.resize(len); //we need to resize after the appendTo for the case str+=foo+str
@@ -455,22 +455,16 @@ template <typename A, typename B>
QString &operator+=(QString &a, const QStringBuilder<A, B> &b)
{
qsizetype len = a.size() + QConcatenable< QStringBuilder<A, B> >::size(b);
- a.reserve(len);
+ a.detach(); // a detach() in a.data() could reset a.capacity() to a.size()
+ if (len > a.data_ptr().freeSpaceAtEnd()) // capacity() was broken when prepend()-optimization landed
+ a.reserve(qMax(len, 2 * a.capacity()));
QChar *it = a.data() + a.size();
QConcatenable< QStringBuilder<A, B> >::appendTo(b, it);
+ // we need to resize after the appendTo for the case str+=foo+str
a.resize(it - a.constData()); //may be smaller than len if there was conversion from utf8
return a;
}
-//
-// inline QAnyStringView members requiring QStringBuilder:
-//
-
-template <typename A, typename B>
-QAnyStringView::QAnyStringView(const QStringBuilder<A, B> &expr,
- typename QStringBuilder<A, B>::ConvertTo &&capacity)
- : QAnyStringView(capacity = expr) {}
-
QT_END_NAMESPACE
#endif // QSTRINGBUILDER_H