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/****************************************************************************
**
** Copyright (C) 2016 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.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include <QtCore/qarraydata.h>
#include <QtCore/private/qtools_p.h>
#include <stdlib.h>
QT_BEGIN_NAMESPACE
QT_WARNING_PUSH
QT_WARNING_DISABLE_GCC("-Wmissing-field-initializers")
const QArrayData QArrayData::shared_null[2] = {
{ Q_REFCOUNT_INITIALIZE_STATIC, 0, 0, 0, sizeof(QArrayData) }, // shared null
/* zero initialized terminator */};
static const QArrayData qt_array[3] = {
{ Q_REFCOUNT_INITIALIZE_STATIC, 0, 0, 0, sizeof(QArrayData) }, // shared empty
{ { Q_BASIC_ATOMIC_INITIALIZER(0) }, 0, 0, 0, sizeof(QArrayData) }, // unsharable empty
/* zero initialized terminator */};
QT_WARNING_POP
static const QArrayData &qt_array_empty = qt_array[0];
static const QArrayData &qt_array_unsharable_empty = qt_array[1];
QArrayData *QArrayData::allocate(size_t objectSize, size_t alignment,
size_t capacity, AllocationOptions options) Q_DECL_NOTHROW
{
// Alignment is a power of two
Q_ASSERT(alignment >= Q_ALIGNOF(QArrayData)
&& !(alignment & (alignment - 1)));
// Don't allocate empty headers
if (!(options & RawData) && !capacity) {
#if QT_SUPPORTS(UNSHARABLE_CONTAINERS)
if (options & Unsharable)
return const_cast<QArrayData *>(&qt_array_unsharable_empty);
#endif
return const_cast<QArrayData *>(&qt_array_empty);
}
size_t headerSize = sizeof(QArrayData);
// Allocate extra (alignment - Q_ALIGNOF(QArrayData)) padding bytes so we
// can properly align the data array. This assumes malloc is able to
// provide appropriate alignment for the header -- as it should!
// Padding is skipped when allocating a header for RawData.
if (!(options & RawData))
headerSize += (alignment - Q_ALIGNOF(QArrayData));
// Allocate additional space if array is growing
if (options & Grow) {
// Guard against integer overflow when multiplying.
if (capacity > std::numeric_limits<size_t>::max() / objectSize)
return 0;
size_t alloc = objectSize * capacity;
// Make sure qAllocMore won't overflow.
if (headerSize > size_t(MaxAllocSize) || alloc > size_t(MaxAllocSize) - headerSize)
return 0;
capacity = qAllocMore(int(alloc), int(headerSize)) / int(objectSize);
}
size_t allocSize = headerSize + objectSize * capacity;
QArrayData *header = static_cast<QArrayData *>(::malloc(allocSize));
if (header) {
quintptr data = (quintptr(header) + sizeof(QArrayData) + alignment - 1)
& ~(alignment - 1);
#if QT_SUPPORTS(UNSHARABLE_CONTAINERS)
header->ref.atomic.store(bool(!(options & Unsharable)));
#else
header->ref.atomic.store(1);
#endif
header->size = 0;
header->alloc = capacity;
header->capacityReserved = bool(options & CapacityReserved);
header->offset = data - quintptr(header);
}
return header;
}
void QArrayData::deallocate(QArrayData *data, size_t objectSize,
size_t alignment) Q_DECL_NOTHROW
{
// Alignment is a power of two
Q_ASSERT(alignment >= Q_ALIGNOF(QArrayData)
&& !(alignment & (alignment - 1)));
Q_UNUSED(objectSize) Q_UNUSED(alignment)
#if QT_SUPPORTS(UNSHARABLE_CONTAINERS)
if (data == &qt_array_unsharable_empty)
return;
#endif
Q_ASSERT_X(data == 0 || !data->ref.isStatic(), "QArrayData::deallocate",
"Static data can not be deleted");
::free(data);
}
namespace QtPrivate {
/*!
\internal
*/
QContainerImplHelper::CutResult QContainerImplHelper::mid(int originalLength, int *_position, int *_length)
{
int &position = *_position;
int &length = *_length;
if (position > originalLength)
return Null;
if (position < 0) {
if (length < 0 || length + position >= originalLength)
return Full;
if (length + position <= 0)
return Null;
length += position;
position = 0;
} else if (uint(length) > uint(originalLength - position)) {
length = originalLength - position;
}
if (position == 0 && length == originalLength)
return Full;
return length > 0 ? Subset : Empty;
}
}
QT_END_NAMESPACE
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