Reimplement JSON support on top of Cbor

In turn, deprecate the QJsonDocument methods that deal with JSON binary
data. You should use CBOR for data serialization these days.

[ChangeLog][Deprecation Notice] The binary JSON representation is
deprecated. The CBOR format should be used instead.

Fixes: QTBUG-47629
Change-Id: Ic8b92ea36de87815b12307a9d8b1095f07166db8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 149 insertions, 0 deletions

diff --git a/src/corelib/serialization/qbinaryjsonobject.cpp b/src/corelib/serialization/qbinaryjsonobject.cpp
new file mode 100644
index 0000000000..3186ab6087
--- /dev/null
+++ b/src/corelib/serialization/qbinaryjsonobject.cpp
@@ -0,0 +1,149 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qbinaryjsonobject_p.h"
+#include "qbinaryjson_p.h"
+
+#include <qjsonobject.h>
+
+QT_BEGIN_NAMESPACE
+
+QBinaryJsonObject::~QBinaryJsonObject()
+{
+    if (d && !d->ref.deref())
+        delete d;
+}
+
+QBinaryJsonObject QBinaryJsonObject::fromJsonObject(const QJsonObject &object)
+{
+    QBinaryJsonObject binary;
+    for (auto it = object.begin(), end = object.end(); it != end; ++it)
+        binary.insert(it.key(), QBinaryJsonValue::fromJsonValue(it.value()));
+    if (binary.d) // We want to compact it as it is a root item now
+        binary.d->compactionCounter++;
+    binary.compact();
+    return binary;
+}
+
+void QBinaryJsonObject::insert(const QString &key, const QBinaryJsonValue &value)
+{
+    bool latinOrIntValue;
+    uint valueSize = QBinaryJsonPrivate::Value::requiredStorage(value, &latinOrIntValue);
+
+    bool latinKey = QBinaryJsonPrivate::useCompressed(key);
+    uint valueOffset = sizeof(QBinaryJsonPrivate::Entry)
+            + QBinaryJsonPrivate::qStringSize(key, latinKey);
+    uint requiredSize = valueOffset + valueSize;
+
+    if (!detach(requiredSize + sizeof(QBinaryJsonPrivate::offset))) // offset for the new index entry
+        return;
+
+    if (!o->length)
+        o->tableOffset = sizeof(QBinaryJsonPrivate::Object);
+
+    bool keyExists = false;
+    uint pos = o->indexOf(key, &keyExists);
+    if (keyExists)
+        ++d->compactionCounter;
+
+    uint off = o->reserveSpace(requiredSize, pos, 1, keyExists);
+    if (!off)
+        return;
+
+    QBinaryJsonPrivate::Entry *e = o->entryAt(pos);
+    e->value.type = value.t;
+    e->value.latinKey = latinKey;
+    e->value.latinOrIntValue = latinOrIntValue;
+    e->value.value = QBinaryJsonPrivate::Value::valueToStore(
+                value, reinterpret_cast<char *>(e) - reinterpret_cast<char *>(o) + valueOffset);
+    QBinaryJsonPrivate::copyString(reinterpret_cast<char *>(e + 1), key, latinKey);
+    if (valueSize) {
+        QBinaryJsonPrivate::Value::copyData(value, reinterpret_cast<char *>(e) + valueOffset,
+                                            latinOrIntValue);
+    }
+
+    if (d->compactionCounter > 32U && d->compactionCounter >= unsigned(o->length) / 2U)
+        compact();
+}
+
+char *QBinaryJsonObject::takeRawData(uint *size) const
+{
+    if (d)
+        return d->takeRawData(size);
+    *size = 0;
+    return nullptr;
+}
+
+bool QBinaryJsonObject::detach(uint reserve)
+{
+    if (!d) {
+        if (reserve >= QBinaryJsonPrivate::Value::MaxSize) {
+            qWarning("QBinaryJson: Document too large to store in data structure");
+            return false;
+        }
+        d = new QBinaryJsonPrivate::MutableData(reserve, QJsonValue::Object);
+        o = static_cast<QBinaryJsonPrivate::Object *>(d->header->root());
+        d->ref.ref();
+        return true;
+    }
+    if (reserve == 0 && d->ref.loadRelaxed() == 1)
+        return true;
+
+    QBinaryJsonPrivate::MutableData *x = d->clone(o, reserve);
+    if (!x)
+        return false;
+    x->ref.ref();
+    if (!d->ref.deref())
+        delete d;
+    d = x;
+    o = static_cast<QBinaryJsonPrivate::Object *>(d->header->root());
+    return true;
+}
+
+void QBinaryJsonObject::compact()
+{
+    if (!d || !d->compactionCounter)
+        return;
+
+    detach();
+    d->compact();
+    o = static_cast<QBinaryJsonPrivate::Object *>(d->header->root());
+}
+
+QT_END_NAMESPACE