Put QPacketProtocol into its own static library

We need it in 3 places in qtdeclarative and we could also use it in
QtCreator. We don't want to bundle it with the debug client code as it
is also necessary for the server.

QPacket replaces QQmlDebugStream as it has the same purpose. This
also fixes the inconsitent handling of data stream versions.

Change-Id: I650fae353f267511c551b427d9169f4d718aa7f2
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

5 files changed, 227 insertions, 39 deletions

diff --git a/src/qml/debugger/debugger.pri b/src/qml/debugger/debugger.pri
index 30a44eedd1..62b375f72f 100644
--- a/src/qml/debugger/debugger.pri
+++ b/src/qml/debugger/debugger.pri
@@ -6,7 +6,8 @@ SOURCES += \
     $$PWD/qqmldebugservice.cpp \
     $$PWD/qqmldebugserviceinterfaces.cpp \
     $$PWD/qqmlabstractprofileradapter.cpp \
-    $$PWD/qqmlprofiler.cpp
+    $$PWD/qqmlprofiler.cpp \
+    $$PWD/qpacket.cpp
 
 HEADERS += \
     $$PWD/qqmldebugconnector_p.h \
@@ -18,6 +19,7 @@ HEADERS += \
     $$PWD/qqmldebug.h \
     $$PWD/qqmlprofilerdefinitions_p.h \
     $$PWD/qqmlabstractprofileradapter_p.h \
-    $$PWD/qqmlprofiler_p.h
+    $$PWD/qqmlprofiler_p.h \
+    $$PWD/qpacket_p.h
 
 INCLUDEPATH += $$PWD
diff --git a/src/qml/debugger/qpacket.cpp b/src/qml/debugger/qpacket.cpp
new file mode 100644
index 0000000000..30f2191689
--- /dev/null
+++ b/src/qml/debugger/qpacket.cpp
@@ -0,0 +1,147 @@
+/****************************************************************************
+**
+** 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
new file mode 100644
index 0000000000..759ed25145
--- /dev/null
+++ b/src/qml/debugger/qpacket_p.h
@@ -0,0 +1,76 @@
+/****************************************************************************
+**
+** 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/qqmldebugservice.cpp b/src/qml/debugger/qqmldebugservice.cpp
index 0b07f320ec..bbcf67a54b 100644
--- a/src/qml/debugger/qqmldebugservice.cpp
+++ b/src/qml/debugger/qqmldebugservice.cpp
@@ -200,32 +200,6 @@ void QQmlDebugService::engineRemoved(QQmlEngine *)
 {
 }
 
-int QQmlDebugStream::s_dataStreamVersion = QDataStream::Qt_4_7;
-
-QQmlDebugStream::QQmlDebugStream()
-    : QDataStream()
-{
-    setVersion(s_dataStreamVersion);
-}
-
-QQmlDebugStream::QQmlDebugStream(QIODevice *d)
-    : QDataStream(d)
-{
-    setVersion(s_dataStreamVersion);
-}
-
-QQmlDebugStream::QQmlDebugStream(QByteArray *ba, QIODevice::OpenMode flags)
-    : QDataStream(ba, flags)
-{
-    setVersion(s_dataStreamVersion);
-}
-
-QQmlDebugStream::QQmlDebugStream(const QByteArray &ba)
-    : QDataStream(ba)
-{
-    setVersion(s_dataStreamVersion);
-}
-
 QT_END_NAMESPACE
 
 #include "qqmldebugservice.moc"
diff --git a/src/qml/debugger/qqmldebugservice_p.h b/src/qml/debugger/qqmldebugservice_p.h
index 3d692133cc..8b58f57349 100644
--- a/src/qml/debugger/qqmldebugservice_p.h
+++ b/src/qml/debugger/qqmldebugservice_p.h
@@ -96,17 +96,6 @@ signals:
     void messagesToClient(const QString &name, const QList<QByteArray> &messages);
 };
 
-class Q_QML_PRIVATE_EXPORT QQmlDebugStream : public QDataStream
-{
-public:
-    static int s_dataStreamVersion;
-
-    QQmlDebugStream();
-    explicit QQmlDebugStream(QIODevice *d);
-    QQmlDebugStream(QByteArray *ba, QIODevice::OpenMode flags);
-    QQmlDebugStream(const QByteArray &ba);
-};
-
 QT_END_NAMESPACE
 
 #endif // QQMLDEBUGSERVICE_H