Introducing QArrayData

Modeled on QByteArrayData/QStringData/QVectorData, the intent is to
unify book-keeping structs for array-like data and enable sharing of
code among them.

As in those structures, size (and alloc) data member(s) specify the
number of *typed* elements the array does (and can) hold.  The size or
alignment requirements of those objects is not tracked in this data
structure and needs to be maintained by its users.

Contrary to QByteArrayData and QStringData, QArrayData's offset member
keeps a *byte* offset to the actual data array and is computed from the
beginning of the struct.

Shared-null and -empty functionality is provided by QArrayData and
shared among all users.

Planned features include setSharable (force deep copies), fromRawData
(detached header and data allocations) and literals a la QStringLiteral
(static immutable instances), thus covering the functionality needed for
QByteArray, QString and QVector.

Change-Id: I9aa709dbb675442e6d06965efb8138ab84602bbd
Reviewed-by: Bradley T. Hughes <bradley.hughes@nokia.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/src/corelib/tools/qarraydata.cpp b/src/corelib/tools/qarraydata.cpp
new file mode 100644
index 0000000000..3b15c0e246
--- /dev/null
+++ b/src/corelib/tools/qarraydata.cpp
@@ -0,0 +1,49 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this
+** file. Please review the following information to ensure the GNU Lesser
+** General Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore/qarraydata.h>
+
+QT_BEGIN_NAMESPACE
+
+const QArrayData QArrayData::shared_null = { Q_REFCOUNT_INITIALIZER(-1), 0, 0, 0, 0 };
+const QArrayData QArrayData::shared_empty = { Q_REFCOUNT_INITIALIZER(-1), 0, 0, 0, 0 };
+
+QT_END_NAMESPACE