QmlDesigner: Add image cache

The image cache is saving images and icon of this images in a sqlite
database. If there are no images they are generated in the backgound.
The icons are fetched by item library.

Task-number: QDS-2782
Task-number: QDS-2783
Task-number: QDS-2858
Change-Id: I5a32cccfef7f8fd8eb78902605a09f5da18ce88e
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/libs/sqlite/sqliteblob.h

@@ -0,0 +1,100 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** 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 General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** 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-3.0.html.
+**
+****************************************************************************/
+
+#pragma once
+
+#include "sqliteglobal.h"
+
+#include <utils/span.h>
+
+#include <QByteArray>
+
+#include <algorithm>
+#include <cstring>
+#include <vector>
+
+namespace Sqlite {
+
+class BlobView
+{
+public:
+    BlobView() = default;
+
+    BlobView(const byte *data, std::size_t size)
+        : m_data(data)
+        , m_size(size)
+    {}
+
+    BlobView(const QByteArray &byteArray)
+        : m_data(reinterpret_cast<const byte *>(byteArray.constData()))
+        , m_size(static_cast<std::size_t>(byteArray.size()))
+    {}
+
+    BlobView(const std::vector<Sqlite::byte> &bytes)
+        : m_data(bytes.data())
+        , m_size(static_cast<std::size_t>(bytes.size()))
+    {}
+
+    const byte *data() const { return m_data; }
+    const char *cdata() const { return reinterpret_cast<const char *>(m_data); }
+    std::size_t size() const { return m_size; }
+    int sisize() const { return static_cast<int>(m_size); }
+    long long ssize() const { return static_cast<long long>(m_size); }
+    bool empty() const { return !m_size; }
+
+    friend bool operator==(Sqlite::BlobView first, Sqlite::BlobView second)
+    {
+        return first.size() == second.size()
+               && std::memcmp(first.data(), second.data(), first.size()) == 0;
+    }
+
+private:
+    const byte *m_data{};
+    std::size_t m_size{};
+};
+
+class Blob
+{
+public:
+    Blob(BlobView blobView)
+    {
+        bytes.reserve(blobView.size());
+        std::copy_n(blobView.data(), blobView.size(), std::back_inserter(bytes));
+    }
+
+    std::vector<Sqlite::byte> bytes;
+};
+
+class ByteArrayBlob
+{
+public:
+    ByteArrayBlob(BlobView blobView)
+        : byteArray{blobView.cdata(), blobView.sisize()}
+    {}
+
+    QByteArray byteArray;
+};
+
+} // namespace Sqlite