Metadata cache: add derived class for metadata cache

By creating a separate class for the metadata cache that inherits
GenericDataCache<Metadata>, we can move the responsibility of setting
up the cache type and version from calling clients to the class
constructors. This way there is less risk of accidentally forgetting
setting the default type and version of the cache - especially the
version, which is always a static value in IFW.

Change-Id: I02f931395ca472a206d51207279fddbe12ba3897
Reviewed-by: Katja Marttila <katja.marttila@qt.io>

7 files changed, 121 insertions, 11 deletions

diff --git a/src/libs/installer/genericdatacache.h b/src/libs/installer/genericdatacache.h
index 5c1732334..94085502c 100644
--- a/src/libs/installer/genericdatacache.h
+++ b/src/libs/installer/genericdatacache.h
@@ -71,7 +71,7 @@ public:
 
     GenericDataCache();
     explicit GenericDataCache(const QString &path, const QString &type, const QString &version);
-    ~GenericDataCache();
+    virtual ~GenericDataCache();
 
     void setType(const QString &type);
     void setVersion(const QString &version);
diff --git a/src/libs/installer/installer.pro b/src/libs/installer/installer.pro
index 5a58968ee..30d15c695 100644
--- a/src/libs/installer/installer.pro
+++ b/src/libs/installer/installer.pro
@@ -52,6 +52,7 @@ HEADERS += packagemanagercore.h \
     genericdatacache.h \
     loggingutils.h \
     metadata.h \
+    metadatacache.h \
     packagemanagercore_p.h \
     packagemanagergui.h \
     binaryformat.h \
@@ -158,6 +159,7 @@ SOURCES += packagemanagercore.cpp \
     genericdatacache.cpp \
     loggingutils.cpp \
     metadata.cpp \
+    metadatacache.cpp \
     operationtracer.cpp \
     packagemanagercore_p.cpp \
     packagemanagergui.cpp \
diff --git a/src/libs/installer/metadatacache.cpp b/src/libs/installer/metadatacache.cpp
new file mode 100644
index 000000000..744e455f4
--- /dev/null
+++ b/src/libs/installer/metadatacache.cpp
@@ -0,0 +1,67 @@
+/**************************************************************************
+**
+** Copyright (C) 2023 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Installer Framework.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** 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.
+**
+** $QT_END_LICENSE$
+**
+**************************************************************************/
+
+#include "metadatacache.h"
+
+#define QUOTE_(x) #x
+#define QUOTE(x) QUOTE_(x)
+
+namespace QInstaller {
+
+/*!
+    \inmodule QtInstallerFramework
+    \class QInstaller::MetadataCache
+    \brief The MetadataCache is a class for a checksum based storage of \c Metadata objects on disk.
+
+    MetadataCache manages a cache storage for a set \l{path()}, which contains
+    a subdirectory for each registered \c Metadata item. The cache has a manifest file in
+    its root directory, which lists the version and type of the cache, and all its items.
+    The file is updated automatically when the metadata cache object is destructed, or
+    it can be updated periodically by calling \l{sync()}.
+*/
+
+/*!
+    Constructs a new empty cache. The cache is invalid until set with a
+    path and initialized.
+*/
+MetadataCache::MetadataCache()
+    : GenericDataCache<Metadata>()
+{
+    setType(QLatin1String("Metadata"));
+    setVersion(QLatin1String(QUOTE(IFW_CACHE_FORMAT_VERSION)));
+}
+
+/*!
+    Constructs a cache to \a path. The cache is initialized automatically.
+*/
+MetadataCache::MetadataCache(const QString &path)
+    : GenericDataCache(path, QLatin1String("Metadata"), QLatin1String(QUOTE(IFW_CACHE_FORMAT_VERSION)))
+{
+}
+
+} // namespace QInstaller
diff --git a/src/libs/installer/metadatacache.h b/src/libs/installer/metadatacache.h
new file mode 100644
index 000000000..804d1b6db
--- /dev/null
+++ b/src/libs/installer/metadatacache.h
@@ -0,0 +1,46 @@
+/**************************************************************************
+**
+** Copyright (C) 2023 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Installer Framework.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** 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.
+**
+** $QT_END_LICENSE$
+**
+**************************************************************************/
+
+#ifndef METADATACACHE_H
+#define METADATACACHE_H
+
+#include "genericdatacache.h"
+#include "metadata.h"
+
+namespace QInstaller {
+
+class MetadataCache : public GenericDataCache<Metadata>
+{
+public:
+    MetadataCache();
+    explicit MetadataCache(const QString &path);
+};
+
+} // namespace QInstaller
+
+#endif // METADATACACHE_H
diff --git a/src/libs/installer/metadatajob.cpp b/src/libs/installer/metadatajob.cpp
index 663b209f7..b5883c66c 100644
--- a/src/libs/installer/metadatajob.cpp
+++ b/src/libs/installer/metadatajob.cpp
@@ -42,9 +42,6 @@
 #include <QtMath>
 #include <QRandomGenerator>
 
-#define QUOTE_(x) #x
-#define QUOTE(x) QUOTE_(x)
-
 namespace QInstaller {
 
 /*!
@@ -192,8 +189,6 @@ bool MetadataJob::resetCache(bool init)
         m_metaFromCache.clear();
 
     m_metaFromCache.setPath(m_core->settings().localCachePath());
-    m_metaFromCache.setType(QLatin1String("Metadata"));
-    m_metaFromCache.setVersion(QLatin1String(QUOTE(IFW_CACHE_FORMAT_VERSION)));
 
     if (!init)
         return true;
diff --git a/src/libs/installer/metadatajob.h b/src/libs/installer/metadatajob.h
index 37d9367e5..1dbb28773 100644
--- a/src/libs/installer/metadatajob.h
+++ b/src/libs/installer/metadatajob.h
@@ -33,7 +33,7 @@
 #include "fileutils.h"
 #include "job.h"
 #include "metadata.h"
-#include "genericdatacache.h"
+#include "metadatacache.h"
 #include "repository.h"
 
 #include <QFutureWatcher>
@@ -133,7 +133,7 @@ private:
 
     QSet<Repository> m_fetchedCategorizedRepositories;
     QHash<QString, Metadata *> m_fetchedMetadata;
-    GenericDataCache<Metadata> m_metaFromCache;
+    MetadataCache m_metaFromCache;
 };
 
 }   // namespace QInstaller
diff --git a/src/libs/installer/metadatajob_p.h b/src/libs/installer/metadatajob_p.h
index 8ab2d9e7d..0bd47b324 100644
--- a/src/libs/installer/metadatajob_p.h
+++ b/src/libs/installer/metadatajob_p.h
@@ -163,7 +163,7 @@ class UpdateCacheTask : public AbstractTask<void>
     Q_DISABLE_COPY(UpdateCacheTask)
 
 public:
-    UpdateCacheTask(GenericDataCache<Metadata> &cache, QHash<QString, Metadata *> &updates)
+    UpdateCacheTask(MetadataCache &cache, QHash<QString, Metadata *> &updates)
         : m_cache(&cache)
         , m_updates(&updates)
     {}
@@ -177,7 +177,7 @@ public:
         QStringList registeredKeys;
         bool success = true;
         for (auto *meta : qAsConst(*m_updates)) {
-            if (!m_cache->registerItem(meta, true, GenericDataCache<Metadata>::Move)) {
+            if (!m_cache->registerItem(meta, true, MetadataCache::Move)) {
                 success = false;
                 break;
             }
@@ -211,7 +211,7 @@ public:
     }
 
 private:
-    GenericDataCache<Metadata> *const m_cache;
+    MetadataCache *const m_cache;
     QHash<QString, Metadata *> *const m_updates;
 };