feat: use singleton connection to systemstats

it has been found in #174, that if there are multiple instances of
widget, it keeps subscribing on all sources, because of how dbus
interface works.

In order to hande it, all subscriptions are now kept from singleton with
tracking active clients

sources/awesome-widget/plugin/awcustomkeyshelper.h

@@ -34,7 +34,7 @@ public:
     [[nodiscard]] QStringList sources() const;
     [[nodiscard]] QStringList refinedSources() const;
     // configuration related
-    void editPairs() override{};
+    void editPairs() override {};
     QStringList leftKeys() override;
     QStringList rightKeys() override;
 };

sources/awesome-widget/plugin/awdataengineaggregator.cpp

@@ -95,13 +95,55 @@ void AWDataEngineAggregator::loadSources()
 }
 
 
+void AWDataEngineAggregator::registerClient(QObject *_client)
+{
+    qCDebug(LOG_AW) << "Register client" << _client;
+
+    // register new client
+    m_clients.insert(_client);
+    // (re)connect sources for new client
+    connectSources();
+}
+
+
+void AWDataEngineAggregator::unregisterClient(QObject *_client)
+{
+    qCDebug(LOG_AW) << "Unregister client" << _client;
+
+    m_clients.remove(_client);
+    for (auto [source, clients] : m_droppedBy.asKeyValueRange()) {
+        if (clients.remove(_client)) {
+            if (isSubscriptionUnused(source))
+                dropSource(source);
+        }
+    }
+}
+
+
 void AWDataEngineAggregator::dropSource(const QString &_source)
 {
     qCDebug(LOG_AW) << "Disconnect sensor" << _source;
 
-    m_interface->unsubscribe({_source}).waitForFinished();
-    m_interface->unsubscribe({_source}).waitForFinished();
-    m_subscribed.remove(_source);
+    if (m_subscribed.remove(_source))
+        m_interface->unsubscribe({_source}).waitForFinished();
+}
+
+
+void AWDataEngineAggregator::dropSourceForClient(QObject *_client, const QString &_source)
+{
+    qCDebug(LOG_AW) << "Client" << _client << "dropping source" << _source;
+
+    m_droppedBy[_source].insert(_client);
+
+    // only unsubscribe if ALL clients have dropped this source
+    if (isSubscriptionUnused(_source))
+        dropSource(_source);
+}
+
+
+bool AWDataEngineAggregator::isSubscriptionUnused(const QString &_source) const
+{
+    return m_droppedBy.value(_source).size() >= m_clients.size() && !m_clients.isEmpty();
 }
 
 

sources/awesome-widget/plugin/awdataengineaggregator.h

@@ -23,6 +23,7 @@
 #include <QObject>
 #include <QSet>
 
+#include <memory>
 
 namespace KSysGuard::SystemStats
 {
@@ -34,12 +35,26 @@ class AWDataEngineAggregator : public QObject
     Q_OBJECT
 
 public:
-    explicit AWDataEngineAggregator(QObject *_parent = nullptr);
     ~AWDataEngineAggregator() override;
+
+    AWDataEngineAggregator(AWDataEngineAggregator &) = delete;
+    void operator=(const AWDataEngineAggregator &) = delete;
+
+    [[nodiscard]] static AWDataEngineAggregator *instance(QObject *_client)
+    {
+        static auto instance = loadInstance();
+        instance->registerClient(_client);
+        return instance.get();
+    };
+
     void connectSources();
     void disconnectSources();
+    void dropSourceForClient(QObject *_client, const QString &_source);
+    [[nodiscard]] inline bool isSubscriptionUnused(const QString &_source) const;
     [[nodiscard]] static bool isValidSensor(const KSysGuard::SensorInfo &_sensor);
     void loadSources();
+    void registerClient(QObject *_client);
+    void unregisterClient(QObject *_client);
 
 signals:
     void dataUpdated(const QHash<QString, KSysGuard::SensorInfo> &_sensors, const KSysGuard::SensorDataList &_data);
@@ -52,7 +67,18 @@ public slots:
     void updateData(const KSysGuard::SensorDataList &_data);
     void updateSensors(const QHash<QString, KSysGuard::SensorInfo> &_sensors);
 
+protected:
+    explicit AWDataEngineAggregator(QObject *_parent = nullptr);
+
+    [[nodiscard]] static std::unique_ptr<AWDataEngineAggregator> loadInstance()
+    {
+        auto instance = new AWDataEngineAggregator();
+        return std::unique_ptr<AWDataEngineAggregator>(instance);
+    };
+
 private:
+    QSet<QObject *> m_clients;
+    QHash<QString, QSet<QObject *>> m_droppedBy;
     KSysGuard::SystemStats::DBusInterface *m_interface = nullptr;
     QHash<QString, KSysGuard::SensorInfo> m_sensors;
     QSet<QString> m_subscribed;

sources/awesome-widget/plugin/awkeys.cpp

@@ -43,7 +43,7 @@ AWKeys::AWKeys(QObject *_parent)
 
     m_aggregator = new AWKeysAggregator(this);
     m_dataAggregator = new AWDataAggregator(this);
-    m_dataEngineAggregator = new AWDataEngineAggregator(this);
+    m_dataEngineAggregator = AWDataEngineAggregator::instance(this);
     m_keyOperator = new AWKeyOperations(this);
 
     m_timer = new QTimer(this);
@@ -59,7 +59,8 @@ AWKeys::AWKeys(QObject *_parent)
     connect(m_dataAggregator, &AWDataAggregator::toolTipPainted,
             [this](const QString &_tooltip) { emit(needToolTipToBeUpdated(_tooltip)); });
 
-    connect(this, &AWKeys::dropSourceFromDataengine, m_dataEngineAggregator, &AWDataEngineAggregator::dropSource);
+    connect(this, &AWKeys::dropSourceFromDataengine, this,
+            [this](const QString &_source) { m_dataEngineAggregator->dropSourceForClient(this, _source); });
     connect(m_dataEngineAggregator, &AWDataEngineAggregator::dataUpdated, this, &AWKeys::dataUpdated);
     // transfer signal from dataengine to update source list
     connect(m_dataEngineAggregator, &AWDataEngineAggregator::deviceAdded, m_keyOperator, &AWKeyOperations::addDevice);
@@ -70,6 +71,8 @@ AWKeys::~AWKeys()
 {
     qCDebug(LOG_AW) << __PRETTY_FUNCTION__;
 
+    m_dataEngineAggregator->unregisterClient(this);
+
     m_timer->stop();
     // delete dbus session
     auto id = reinterpret_cast<qlonglong>(this);
@@ -294,8 +297,8 @@ QString AWKeys::parsePattern(QString _pattern) const
     // bars
     for (auto &bar : m_foundBars) {
         auto item = m_keyOperator->giByKey(bar);
-        auto image = item->isCustom() ? item->image(
-                         AWPatternFunctions::expandLambdas(item->bar(), m_aggregator, m_values, item->usedKeys()))
+        auto image = item->isCustom() ? item->image(AWPatternFunctions::expandLambdas(item->bar(), m_aggregator,
+                                                                                      m_values, item->usedKeys()))
                                       : item->image(m_values[item->bar()]);
         _pattern.replace(QString("$%1").arg(bar), image);
     }

sources/awesome-widget/plugin/formatters/awpluginformatter.h

@@ -32,7 +32,7 @@ public:
     [[nodiscard]] virtual QString format(const QVariant &_value, const QString &_key,
                                          const AWPluginFormatSettings &_settings) const
         = 0;
-    virtual void load(){};
+    virtual void load() {};
 };