QmlDebug: Restructure QPacket and QPacketProtocol

We cannot use the same data stream version for the client and server
versions of QPacket and QPacketProtocol should not deal with QPackets
but with simple byte arrays because the underlying QDataStream is hard
to copy.

The new QQmlDebugPacket picks its data stream version from
QQmlDebugConnector now, which adjusts it when connecting. As there can
only ever be one QQmlDebugConnector, we can keep the version static.

The clients need to query the connection for the correct version. We
may connect to several different servers sequentially or we may have a
server running while using a client, and we don't want to confuse the
versions between those.

With this in place, all remaining occurrences of QDataStream are
replaced with QPacket or QQmlDebugPacket.

Change-Id: I3f6ba73fcbfad5e8df917c5feb9308116738a614
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

6 files changed, 10 insertions, 228 deletions

diff --git a/src/qml/debugger/debugger.pri b/src/qml/debugger/debugger.pri
index 62b375f72f..30a44eedd1 100644
--- a/src/qml/debugger/debugger.pri
+++ b/src/qml/debugger/debugger.pri
@@ -6,8 +6,7 @@ SOURCES += \
     $$PWD/qqmldebugservice.cpp \
     $$PWD/qqmldebugserviceinterfaces.cpp \
     $$PWD/qqmlabstractprofileradapter.cpp \
-    $$PWD/qqmlprofiler.cpp \
-    $$PWD/qpacket.cpp
+    $$PWD/qqmlprofiler.cpp
 
 HEADERS += \
     $$PWD/qqmldebugconnector_p.h \
@@ -19,7 +18,6 @@ HEADERS += \
     $$PWD/qqmldebug.h \
     $$PWD/qqmlprofilerdefinitions_p.h \
     $$PWD/qqmlabstractprofileradapter_p.h \
-    $$PWD/qqmlprofiler_p.h \
-    $$PWD/qpacket_p.h
+    $$PWD/qqmlprofiler_p.h
 
 INCLUDEPATH += $$PWD
diff --git a/src/qml/debugger/qpacket.cpp b/src/qml/debugger/qpacket.cpp
deleted file mode 100644
index 30f2191689..0000000000
--- a/src/qml/debugger/qpacket.cpp
+++ /dev/null
@@ -1,147 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL21$
-** 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 http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://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 2.1 or version 3 as published by the Free
-** Software Foundation and appearing in the file LICENSE.LGPLv21 and
-** LICENSE.LGPLv3 included in the packaging of this file. Please review the
-** following information to ensure the GNU Lesser General Public License
-** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
-** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
-**
-** As a special exception, The Qt Company gives you certain additional
-** rights. These rights are described in The Qt Company LGPL Exception
-** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qpacket_p.h"
-
-QT_BEGIN_NAMESPACE
-
-/*!
-  \class QPacket
-  \internal
-
-  \brief The QPacket class encapsulates an unfragmentable packet of data to be
-  transmitted by QPacketProtocol.
-
-  The QPacket class works together with QPacketProtocol to make it simple to
-  send arbitrary sized data "packets" across fragmented transports such as TCP
-  and UDP.
-
-  QPacket provides a QDataStream interface to an unfragmentable packet.
-  Applications should construct a QPacket, propagate it with data and then
-  transmit it over a QPacketProtocol instance.  For example:
-  \code
-  QPacketProtocol protocol(...);
-
-  QPacket myPacket;
-  myPacket << "Hello world!" << 123;
-  protocol.send(myPacket);
-  \endcode
-
-  As long as both ends of the connection are using the QPacketProtocol class,
-  the data within this packet will be delivered unfragmented at the other end,
-  ready for extraction.
-
-  \code
-  QByteArray greeting;
-  int count;
-
-  QPacket myPacket = protocol.read();
-
-  myPacket >> greeting >> count;
-  \endcode
-
-  Only packets constructed from raw byte arrays may be read from. Empty QPacket
-  instances are for transmission only and are considered "write only". Attempting
-  to read data from them will result in undefined behavior.
-
-  \ingroup io
-  \sa QPacketProtocol
- */
-
-int QPacket::s_dataStreamVersion = QDataStream::Qt_4_7;
-
-void QPacket::setDataStreamVersion(int dataStreamVersion)
-{
-    s_dataStreamVersion = dataStreamVersion;
-}
-
-int QPacket::dataStreamVersion()
-{
-    return s_dataStreamVersion;
-}
-
-/*!
-  Constructs an empty write-only packet.
-  */
-QPacket::QPacket()
-{
-    init(QIODevice::WriteOnly);
-}
-
-/*!
-  Creates a copy of \a other.  The initial stream positions are shared, but the
-  two packets are otherwise independent.
- */
-QPacket::QPacket(const QPacket &other) : QDataStream()
-{
-    assign(other);
-}
-
-QPacket &QPacket::operator=(const QPacket &other)
-{
-    if (this != &other) {
-        buf.close();
-        assign(other);
-    }
-    return *this;
-}
-
-QPacket::QPacket(const QByteArray &data)
-{
-    buf.setData(data);
-    init(QIODevice::ReadOnly);
-}
-
-/*!
-  Returns raw packet data.
-  */
-QByteArray QPacket::data() const
-{
-    return buf.data();
-}
-
-void QPacket::init(QIODevice::OpenMode mode)
-{
-    buf.open(mode);
-    setDevice(&buf);
-    setVersion(s_dataStreamVersion);
-}
-
-void QPacket::assign(const QPacket &other)
-{
-    buf.setData(other.buf.data());
-    init(other.buf.openMode());
-    buf.seek(other.buf.pos());
-}
-
-QT_END_NAMESPACE
diff --git a/src/qml/debugger/qpacket_p.h b/src/qml/debugger/qpacket_p.h
deleted file mode 100644
index 759ed25145..0000000000
--- a/src/qml/debugger/qpacket_p.h
+++ /dev/null
@@ -1,76 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL21$
-** 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 http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://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 2.1 or version 3 as published by the Free
-** Software Foundation and appearing in the file LICENSE.LGPLv21 and
-** LICENSE.LGPLv3 included in the packaging of this file. Please review the
-** following information to ensure the GNU Lesser General Public License
-** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
-** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
-**
-** As a special exception, The Qt Company gives you certain additional
-** rights. These rights are described in The Qt Company LGPL Exception
-** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QPACKET_P_H
-#define QPACKET_P_H
-
-#include <QtCore/qdatastream.h>
-#include <QtCore/qbuffer.h>
-#include <QtQml/private/qtqmlglobal_p.h>
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-QT_BEGIN_NAMESPACE
-
-class Q_QML_PRIVATE_EXPORT QPacket : public QDataStream
-{
-public:
-    QPacket();
-    QPacket(const QPacket &other);
-    explicit QPacket(const QByteArray &ba);
-    QPacket &operator=(const QPacket &other);
-
-    QByteArray data() const;
-
-    static int dataStreamVersion();
-    static void setDataStreamVersion(int dataStreamVersion);
-
-private:
-    static int s_dataStreamVersion;
-    void init(QIODevice::OpenMode mode);
-    void assign(const QPacket &other);
-    QBuffer buf;
-};
-
-QT_END_NAMESPACE
-
-#endif // QPACKET_P_H
diff --git a/src/qml/debugger/qqmldebugconnector.cpp b/src/qml/debugger/qqmldebugconnector.cpp
index 64a8a49bb9..7d9f462fe2 100644
--- a/src/qml/debugger/qqmldebugconnector.cpp
+++ b/src/qml/debugger/qqmldebugconnector.cpp
@@ -39,6 +39,7 @@
 #include <QtCore/QDir>
 #include <QtCore/QDebug>
 #include <QtCore/QJsonArray>
+#include <QtCore/QDataStream>
 
 #include <private/qcoreapplication_p.h>
 #include <private/qqmlengine_p.h>
@@ -56,6 +57,8 @@ Q_QML_IMPORT_DEBUG_PLUGIN(QQmlInspectorServiceFactory)
 Q_QML_IMPORT_DEBUG_PLUGIN(QQmlProfilerServiceFactory)
 Q_QML_IMPORT_DEBUG_PLUGIN(QQmlDebuggerServiceFactory)
 
+int QQmlDebugConnector::s_dataStreamVersion = QDataStream::Qt_4_7;
+
 struct QQmlDebugConnectorParams {
     QString pluginKey;
     QStringList services;
diff --git a/src/qml/debugger/qqmldebugconnector_p.h b/src/qml/debugger/qqmldebugconnector_p.h
index f5f5a87b56..499f0ece32 100644
--- a/src/qml/debugger/qqmldebugconnector_p.h
+++ b/src/qml/debugger/qqmldebugconnector_p.h
@@ -60,6 +60,10 @@ public:
     static void setPluginKey(const QString &key);
     static void setServices(const QStringList &services);
     static QQmlDebugConnector *instance();
+    static int dataStreamVersion()
+    {
+        return s_dataStreamVersion;
+    }
 
     virtual bool blockingMode() const = 0;
 
@@ -82,6 +86,7 @@ public:
 
 protected:
     static QString commandLineArguments();
+    static int s_dataStreamVersion;
 };
 
 class Q_QML_PRIVATE_EXPORT QQmlDebugConnectorFactory : public QObject {
diff --git a/src/qml/debugger/qqmldebugservice_p.h b/src/qml/debugger/qqmldebugservice_p.h
index 8b58f57349..d95d7c4357 100644
--- a/src/qml/debugger/qqmldebugservice_p.h
+++ b/src/qml/debugger/qqmldebugservice_p.h
@@ -35,7 +35,6 @@
 #define QQMLDEBUGSERVICE_H
 
 #include <QtCore/qobject.h>
-#include <QtCore/qdatastream.h>
 #include <QtCore/qhash.h>
 
 #include <private/qtqmlglobal_p.h>