[libcalamares] Add KPMCore manager

- This handles cleaning up KPMCore on exit

src/libcalamares/CMakeLists.txt

@@ -117,6 +117,7 @@ if ( KPMcore_FOUND )
     include_directories( ${KPMCORE_INCLUDE_DIR} )
     list( APPEND libSources
         partition/FileSystem.cpp
+        partition/KPMManager.cpp
         partition/PartitionIterator.cpp
         partition/PartitionQuery.cpp
     )

src/libcalamares/partition/KPMManager.cpp

@@ -0,0 +1,104 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019, Adriaan de Groot <groot@kde.org>
+ *
+ *   Calamares is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   Calamares 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 General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "KPMManager.h"
+
+#include "utils/Logger.h"
+
+#include <kpmcore/backend/corebackendmanager.h>
+#if defined( WITH_KPMCORE4API )
+#include <kpmcore/util/externalcommand.h>
+#endif
+
+
+#include <QObject>
+
+
+namespace CalamaresUtils
+{
+namespace Partition
+{
+class InternalManager
+{
+public:
+    InternalManager();
+    ~InternalManager();
+};
+
+static bool s_kpm_loaded = false;
+static bool s_loaded = false;
+static std::shared_ptr< InternalManager > s_backend;
+
+
+InternalManager::InternalManager()
+{
+    Q_ASSERT( !s_loaded );
+    s_loaded = true;
+    s_backend.reset( this );
+
+    cDebug() << "KPMCore backend starting ..";
+    if ( !s_kpm_loaded )
+    {
+        QByteArray backendName = qgetenv( "KPMCORE_BACKEND" );
+        if ( !CoreBackendManager::self()->load( backendName.isEmpty() ? CoreBackendManager::defaultBackendName()
+                                                                      : backendName ) )
+        {
+            cWarning() << "Failed to load backend plugin" << backendName;
+        }
+        else
+        {
+            s_kpm_loaded = true;
+        }
+    }
+}
+
+InternalManager::~InternalManager()
+{
+    cDebug() << "Cleaning up KPMCore backend ..";
+
+    s_loaded = false;
+
+#if defined( WITH_KPMCORE4API )
+    auto backend_p = CoreBackendManager::self()->backend();
+    if ( backend_p )
+    {
+        ExternalCommand::stopHelper();
+    }
+#endif
+}
+
+std::shared_ptr< InternalManager >
+getInternal()
+{
+
+    if ( !s_loaded )
+    {
+        return std::make_shared< InternalManager >();
+    }
+    return s_backend;
+}
+
+KPMManager::KPMManager()
+    : m_d( getInternal() )
+{
+}
+
+KPMManager::~KPMManager() {}
+
+}  // namespace Partition
+}  // namespace CalamaresUtils

src/libcalamares/partition/KPMManager.h

@@ -0,0 +1,58 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019, Adriaan de Groot <groot@kde.org>
+ *
+ *   Calamares is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   Calamares 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 General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef PARTITION_KPMMANAGER_H
+#define PARTITION_KPMMANAGER_H
+
+#include <memory>
+
+class CoreBackend;
+
+namespace CalamaresUtils
+{
+namespace Partition
+{
+/// @brief Handle to KPMCore
+class InternalManager;
+
+/** @brief KPMCore loader and cleanup
+ *
+ * A Calamares plugin that uses KPMCore should hold an object of
+ * this class; its only responsibility is to load KPMCore
+ * and to cleanly unload it on destruction (with KPMCore 4,
+ * also to shutdown the privileged helper application).
+ *
+ * It loads the default plugin ("parted" with KPMCore 3, "sfdisk"
+ * with KPMCore 4), but this can be overridden by setting the
+ * environment variable KPMCORE_BACKEND. Setting it to
+ * "dummy" will load the dummy plugin instead.
+ */
+class KPMManager
+{
+public:
+    KPMManager();
+    ~KPMManager();
+
+private:
+    std::shared_ptr< InternalManager > m_d;
+};
+
+}  // namespace Partition
+}  // namespace CalamaresUtils
+
+#endif  // PARTITION_KPMMANAGER_H