Split cborstream feature in two

Reading of Cbor streams is substantially more complicated than writing
as it requires float16 support. When writing Cbor, we can just choose to
always write 32bit floats, even if we could compress the numbers into
16 bits.

We need Cbor writing in the bootstrap library, but we cannot easily add
float16 support.

Furthermore, Cbor reading is required for plugin support, but not Cbor
writing. It might make sense for some users to build a custom Qt with
Cbor writing disabled.

Therefore, provide two features, cborstreamreader and cborstreamwriter,
split up the code in cborstream.{h|cpp} into several files, and enable
Cbor writing in the bootstrap library.

Change-Id: I15450afb0e328a84a22ebca9379cffc4f900a75a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 130 insertions, 0 deletions

diff --git a/src/corelib/serialization/qcborstreamwriter.h b/src/corelib/serialization/qcborstreamwriter.h
new file mode 100644
index 0000000000..f8c94ceb93
--- /dev/null
+++ b/src/corelib/serialization/qcborstreamwriter.h
@@ -0,0 +1,130 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Intel Corporation.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module 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 The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://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 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QCBORSTREAMWRITER_H
+#define QCBORSTREAMWRITER_H
+
+#include <QtCore/qbytearray.h>
+#include <QtCore/qcborcommon.h>
+#include <QtCore/qscopedpointer.h>
+#include <QtCore/qstring.h>
+#include <QtCore/qstringview.h>
+#ifndef QT_BOOTSTRAPPED
+#include <QtCore/qfloat16.h>
+#endif
+
+QT_REQUIRE_CONFIG(cborstreamwriter);
+
+// See qcborcommon.h for why we check
+#if defined(QT_X11_DEFINES_FOUND)
+#  undef True
+#  undef False
+#endif
+
+QT_BEGIN_NAMESPACE
+
+class QIODevice;
+
+class QCborStreamWriterPrivate;
+class Q_CORE_EXPORT QCborStreamWriter
+{
+public:
+    explicit QCborStreamWriter(QIODevice *device);
+    explicit QCborStreamWriter(QByteArray *data);
+    ~QCborStreamWriter();
+    Q_DISABLE_COPY(QCborStreamWriter)
+
+    void setDevice(QIODevice *device);
+    QIODevice *device() const;
+
+    void append(quint64 u);
+    void append(qint64 i);
+    void append(QCborNegativeInteger n);
+    void append(const QByteArray &ba)       { appendByteString(ba.constData(), ba.size()); }
+    void append(QLatin1String str);
+    void append(QStringView str);
+    void append(QCborTag tag);
+    void append(QCborKnownTags tag)         { append(QCborTag(tag)); }
+    void append(QCborSimpleType st);
+    void append(std::nullptr_t)             { append(QCborSimpleType::Null); }
+#ifndef QT_BOOTSTRAPPED
+    void append(qfloat16 f);
+#endif
+    void append(float f);
+    void append(double d);
+
+    void appendByteString(const char *data, qsizetype len);
+    void appendTextString(const char *utf8, qsizetype len);
+
+    // convenience
+    void append(bool b)     { append(b ? QCborSimpleType::True : QCborSimpleType::False); }
+    void appendNull()       { append(QCborSimpleType::Null); }
+    void appendUndefined()  { append(QCborSimpleType::Undefined); }
+
+#ifndef Q_QDOC
+    // overloads to make normal code not complain
+    void append(int i)      { append(qint64(i)); }
+    void append(uint u)     { append(quint64(u)); }
+#endif
+#ifndef QT_NO_CAST_FROM_ASCII
+    void append(const char *str, qsizetype size = -1)
+    { appendTextString(str, (str && size == -1)  ? int(strlen(str)) : size); }
+#endif
+
+    void startArray();
+    void startArray(quint64 count);
+    bool endArray();
+    void startMap();
+    void startMap(quint64 count);
+    bool endMap();
+
+    // no API for encoding chunked strings
+
+private:
+    QScopedPointer<QCborStreamWriterPrivate> d;
+};
+
+QT_END_NAMESPACE
+
+#if defined(QT_X11_DEFINES_FOUND)
+#  define True  1
+#  define False 0
+#endif
+
+#endif // QCBORSTREAMWRITER_H