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>

3 files changed, 211 insertions, 0 deletions

diff --git a/tests/auto/corelib/tools/qringbuffer/tst_qringbuffer.cpp b/tests/auto/corelib/tools/qringbuffer/tst_qringbuffer.cpp
index a2d686d5d8..579d6cfe95 100644
--- a/tests/auto/corelib/tools/qringbuffer/tst_qringbuffer.cpp
+++ b/tests/auto/corelib/tools/qringbuffer/tst_qringbuffer.cpp
@@ -54,7 +54,13 @@ private slots:
     void sizeWhenEmpty();
     void sizeWhenReservedAndChopped();
     void sizeWhenReserved();
+    void free();
+    void reserveAndRead();
+    void chop();
+    void ungetChar();
+    void indexOf();
     void appendAndRead();
+    void readLine();
 };
 
 void tst_QRingBuffer::sizeWhenReserved()
@@ -180,6 +186,93 @@ void tst_QRingBuffer::readPointerAtPositionWriteRead()
     QVERIFY(outData.buffer().startsWith(inData.buffer()));
 }
 
+void tst_QRingBuffer::free()
+{
+    QRingBuffer ringBuffer;
+    // make three byte arrays with different sizes
+    ringBuffer.reserve(4096);
+    ringBuffer.reserve(2048);
+    ringBuffer.append(QByteArray("01234", 5));
+
+    ringBuffer.free(1);
+    QCOMPARE(ringBuffer.size(), 4095 + 2048 + 5);
+    ringBuffer.free(4096);
+    QCOMPARE(ringBuffer.size(), 2047 + 5);
+    ringBuffer.free(48);
+    ringBuffer.free(2000);
+    QCOMPARE(ringBuffer.size(), 4);
+    QVERIFY(memcmp(ringBuffer.readPointer(), "1234", 4) == 0);
+}
+
+void tst_QRingBuffer::reserveAndRead()
+{
+    QRingBuffer ringBuffer;
+    // fill buffer with an arithmetic progression
+    for (int i = 1; i < 256; ++i) {
+        QByteArray ba(i, char(i));
+        char *ringPos = ringBuffer.reserve(i);
+        QVERIFY(ringPos);
+        memcpy(ringPos, ba.constData(), i);
+    }
+
+    // readback and check stored data
+    for (int i = 1; i < 256; ++i) {
+        QByteArray ba;
+        ba.resize(i);
+        int thisRead = ringBuffer.read(ba.data(), i);
+        QCOMPARE(thisRead, i);
+        QVERIFY(ba.count(char(i)) == i);
+    }
+    QVERIFY(ringBuffer.size() == 0);
+}
+
+void tst_QRingBuffer::chop()
+{
+    QRingBuffer ringBuffer;
+    // make three byte arrays with different sizes
+    ringBuffer.append(QByteArray("01234", 5));
+    ringBuffer.reserve(2048);
+    ringBuffer.reserve(4096);
+
+    ringBuffer.chop(1);
+    QCOMPARE(ringBuffer.size(), 5 + 2048 + 4095);
+    ringBuffer.chop(4096);
+    QCOMPARE(ringBuffer.size(), 5 + 2047);
+    ringBuffer.chop(48);
+    ringBuffer.chop(2000);
+    QCOMPARE(ringBuffer.size(), 4);
+    QVERIFY(memcmp(ringBuffer.readPointer(), "0123", 4) == 0);
+}
+
+void tst_QRingBuffer::ungetChar()
+{
+    QRingBuffer ringBuffer(16);
+    for (int i = 1; i < 32; ++i)
+        ringBuffer.putChar(char(i));
+
+    for (int i = 1; i < 31; ++i) {
+        int c = ringBuffer.getChar();
+        QVERIFY(c == 1);
+        ringBuffer.getChar();
+        ringBuffer.ungetChar(char(c)); // unget first char
+    }
+    QCOMPARE(ringBuffer.size(), 1);
+}
+
+void tst_QRingBuffer::indexOf()
+{
+    QRingBuffer ringBuffer(16);
+    for (int i = 1; i < 256; ++i)
+        ringBuffer.putChar(char(i));
+
+    for (int i = 1; i < 256; ++i) {
+        int index = ringBuffer.indexOf(char(i));
+        QCOMPARE(i - 1, index);
+        QCOMPARE(index, ringBuffer.indexOf(char(i), i));
+        QVERIFY(ringBuffer.indexOf(char(i), i - 1) == -1); // test for absent char
+    }
+}
+
 void tst_QRingBuffer::appendAndRead()
 {
     QRingBuffer ringBuffer;
@@ -195,5 +288,32 @@ void tst_QRingBuffer::appendAndRead()
     QVERIFY(ringBuffer.read() == ba3);
 }
 
+void tst_QRingBuffer::readLine()
+{
+    QRingBuffer ringBuffer;
+    QByteArray ba1("Hello world!\n", 13);
+    QByteArray ba2("\n", 1);
+    QByteArray ba3("Test string.", 12);
+    QByteArray ba4("0123456789", 10);
+    ringBuffer.append(ba1);
+    ringBuffer.append(ba2);
+    ringBuffer.append(ba3 + ba4 + ba2);
+
+    char stringBuf[102];
+    stringBuf[101] = 0; // non-crash terminator
+    QVERIFY(ringBuffer.readLine(stringBuf, sizeof(stringBuf) - 2) == ba1.size());
+    QVERIFY(QByteArray(stringBuf, strlen(stringBuf)) == ba1);
+
+    // check first empty string reading
+    stringBuf[0] = 0xFF;
+    QCOMPARE(ringBuffer.readLine(stringBuf, sizeof(stringBuf) - 2), ba2.size());
+    QVERIFY(stringBuf[0] == ba2[0]);
+
+    QVERIFY(ringBuffer.readLine(stringBuf, sizeof(stringBuf) - 2) == (ba3.size() + ba4.size()
+        + ba2.size()));
+    QVERIFY(QByteArray(stringBuf, strlen(stringBuf)) == (ba3 + ba4 + ba2));
+    QVERIFY(ringBuffer.size() == 0);
+}
+
 QTEST_APPLESS_MAIN(tst_QRingBuffer)
 #include "tst_qringbuffer.moc"
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