From 76a3570ab2f9fab98aa6ccc9ceafbbc29323db06 Mon Sep 17 00:00:00 2001
From: David Edmundson <kde@davidedmundson.co.uk>
Date: Thu, 4 Feb 2021 10:47:43 +0000
Subject: [PATCH] Add method CGroupDataModel::isAvailable

This returns true if the root is pointing to a valid path. The idea
being that non-systemd systems won't have applications scoped correctly,
nor a relevant user slice.

By communicating this we can dislpay the entry as not working in the UI.


(cherry picked from commit 6d42960456f145d178579a1debb726bd0c7dcee6)
---
 processcore/cgroup_data_model.cpp | 21 ++++++++++++++++++++-
 processcore/cgroup_data_model.h   |  5 +++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/processcore/cgroup_data_model.cpp b/processcore/cgroup_data_model.cpp
index 46a36c3..4278a2c 100644
--- a/processcore/cgroup_data_model.cpp
+++ b/processcore/cgroup_data_model.cpp
@@ -48,6 +48,7 @@ public:
     QHash<QString, KSysGuard::ProcessAttribute* > m_availableAttributes;
     QVector<KSysGuard::ProcessAttribute* > m_enabledAttributes;
 
+    bool m_available = false;
     QString m_root;
     QScopedPointer<CGroup> m_rootGroup;
 
@@ -367,9 +368,22 @@ void CGroupDataModel::setRoot(const QString &root)
         return;
     }
     d->m_root = root;
-    d->m_rootGroup.reset(new CGroup(root));
     emit rootChanged();
     QMetaObject::invokeMethod(this, [this] {update();}, Qt::QueuedConnection);
+
+    const QString path = CGroup::cgroupSysBasePath() + root;
+    bool available = QFile::exists(path);
+
+    if (available) {
+        d->m_rootGroup.reset(new CGroup(root));
+    } else {
+        d->m_rootGroup.reset();
+    }
+
+    if (available != d->m_available) {
+        d->m_available = available;
+        emit availableChanged();
+    }
 }
 
 void CGroupDataModel::update()
@@ -443,6 +457,11 @@ void CGroupDataModel::update(CGroup *node)
     }
 }
 
+bool CGroupDataModel::isAvailable() const
+{
+    return d->m_available;
+}
+
 QVector<Process*> CGroupDataModelPrivate::processesFor(CGroup *app)
 {
     if (m_processMap.contains(app)) {
diff --git a/processcore/cgroup_data_model.h b/processcore/cgroup_data_model.h
index 5ce58aa..1f7d28d 100644
--- a/processcore/cgroup_data_model.h
+++ b/processcore/cgroup_data_model.h
@@ -59,6 +59,8 @@ class Q_DECL_EXPORT CGroupDataModel : public QAbstractItemModel
      */
     Q_PROPERTY(QString setRoot READ root WRITE setRoot NOTIFY rootChanged)
 
+    Q_PROPERTY(bool available READ isAvailable NOTIFY availableChanged)
+
 public:
     CGroupDataModel(QObject *parent = nullptr);
     CGroupDataModel(const QString &root, QObject *parent = nullptr);
@@ -114,10 +116,13 @@ public:
      */
     void update();
 
+    bool isAvailable() const;
+
 Q_SIGNALS:
     void enabledAttributesChanged();
     void enabledChanged();
     void rootChanged();
+    void availableChanged();
 
 protected:
     virtual bool filterAcceptsCGroup(const QString &id);
-- 
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