Rewrite QRingBuffer

QRingBuffer is a fully inlined class used in many I/O classes.
So, it must be as fast and small as possible. To this end, a lot of
unnecessary special cases were replaced by generic structures.

Change-Id: Ic189ced3b200924da158ce511d69d324337d01b6
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>

2 files changed, 91 insertions, 0 deletions

diff --git a/tests/benchmarks/corelib/tools/qringbuffer/main.cpp b/tests/benchmarks/corelib/tools/qringbuffer/main.cpp
new file mode 100644
index 0000000000..ebc87aa0cb
--- /dev/null
+++ b/tests/benchmarks/corelib/tools/qringbuffer/main.cpp
@@ -0,0 +1,84 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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 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, Digia gives you certain additional
+** rights.  These rights are described in the Digia 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.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <private/qringbuffer_p.h>
+#include <QByteArray>
+
+#include <qtest.h>
+
+class tst_qringbuffer : public QObject
+{
+    Q_OBJECT
+private slots:
+    void reserveAndRead();
+    void free();
+};
+
+void tst_qringbuffer::reserveAndRead()
+{
+    QRingBuffer ringBuffer;
+    QBENCHMARK {
+        for (int i = 1; i < 256; ++i)
+            ringBuffer.reserve(i);
+
+        for (int i = 1; i < 256; ++i)
+            ringBuffer.read(0, i);
+    }
+}
+
+void tst_qringbuffer::free()
+{
+    QRingBuffer ringBuffer;
+    QBENCHMARK {
+        ringBuffer.reserve(4096);
+        ringBuffer.reserve(2048);
+        ringBuffer.append(QByteArray("01234", 5));
+
+        ringBuffer.free(1);
+        ringBuffer.free(4096);
+        ringBuffer.free(48);
+        ringBuffer.free(2000);
+    }
+}
+
+QTEST_MAIN(tst_qringbuffer)
+
+#include "main.moc"
diff --git a/tests/benchmarks/corelib/tools/qringbuffer/qringbuffer.pro b/tests/benchmarks/corelib/tools/qringbuffer/qringbuffer.pro
new file mode 100644
index 0000000000..21b50e10e5
--- /dev/null
+++ b/tests/benchmarks/corelib/tools/qringbuffer/qringbuffer.pro
@@ -0,0 +1,7 @@
+TEMPLATE = app
+TARGET = tst_bench_qringbuffer
+
+QT = core-private testlib
+CONFIG += release
+
+SOURCES += main.cpp