New Key API in storage layer

Summary:
- Use object oriented paradigm for Keys / Identifiers /Revisions
- "Compress" keys by using byte representation of Uuids
- Still some cleaning left to do
- Also run some benchmarks
- I'm questioning whether files other than entitystore (tests excluded) are allowed to access this API

Reviewers: cmollekopf

Reviewed By: cmollekopf

Tags: #sink

Differential Revision: https://phabricator.kde.org/D13735

1 files changed, 100 insertions, 0 deletions

diff --git a/common/storage/key.h b/common/storage/key.h
new file mode 100644
index 0000000..76dbd13
--- /dev/null
+++ b/common/storage/key.h
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2014 Christian Mollekopf <chrigi_1@fastmail.fm>
+ * Copyright (C) 2018 Rémi Nicole <minijackson@riseup.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) version 3, or any
+ * later version accepted by the membership of KDE e.V. (or its
+ * successor approved by the membership of KDE e.V.), which shall
+ * act as a proxy defined in Section 6 of version 3 of the license.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "sink_export.h"
+
+#include <QByteArray>
+#include <QDebug>
+#include <QUuid>
+
+namespace Sink {
+namespace Storage {
+
+class Identifier
+{
+public:
+    // RFC 4122 Section 4.1.2 says 128 bits -> 16 bytes
+    static const constexpr size_t INTERNAL_REPR_SIZE = 16;
+    static const constexpr size_t DISPLAY_REPR_SIZE = 38;
+
+    Identifier() : uid(QUuid::createUuid()){};
+
+    QByteArray toInternalByteArray() const;
+    static Identifier fromInternalByteArray(const QByteArray &bytes);
+    QString toDisplayString() const;
+    QByteArray toDisplayByteArray() const;
+    static Identifier fromDisplayByteArray(const QByteArray &bytes);
+
+private:
+    explicit Identifier(const QUuid &uid) : uid(uid) {}
+    QUuid uid;
+};
+
+class Revision
+{
+public:
+    // qint64 has a 19 digit decimal representation
+    static const constexpr size_t INTERNAL_REPR_SIZE = 19;
+    static const constexpr size_t DISPLAY_REPR_SIZE = 19;
+
+    Revision(qint64 rev) : rev(rev) {}
+
+    QByteArray toInternalByteArray() const;
+    static Revision fromInternalByteArray(const QByteArray &bytes);
+    QString toDisplayString() const;
+    QByteArray toDisplayByteArray() const;
+    static Revision fromDisplayByteArray(const QByteArray &bytes);
+    qint64 toQint64() const;
+
+private:
+    qint64 rev;
+};
+
+class Key
+{
+public:
+    static const constexpr size_t INTERNAL_REPR_SIZE = Identifier::INTERNAL_REPR_SIZE + Revision::INTERNAL_REPR_SIZE;
+    static const constexpr size_t DISPLAY_REPR_SIZE = Identifier::DISPLAY_REPR_SIZE + Revision::DISPLAY_REPR_SIZE;
+
+    Key(const Identifier &id, const Revision &rev) : id(id), rev(rev) {}
+
+    QByteArray toInternalByteArray() const;
+    static Key fromInternalByteArray(const QByteArray &bytes);
+    QString toDisplayString() const;
+    QByteArray toDisplayByteArray() const;
+    static Key fromDisplayByteArray(const QByteArray &bytes);
+    const Identifier &identifier() const;
+    const Revision &revision() const;
+    void setRevision(const Revision &newRev);
+
+private:
+    Identifier id;
+    Revision rev;
+};
+
+} // namespace Storage
+} // namespace Sink
+
+SINK_EXPORT QDebug& operator<<(QDebug &dbg, const Sink::Storage::Identifier &);
+SINK_EXPORT QDebug& operator<<(QDebug &dbg, const Sink::Storage::Revision &);
+SINK_EXPORT QDebug& operator<<(QDebug &dbg, const Sink::Storage::Key &);