limit the rate with which progress is sent via MPRIS

BUG: 416179

src/mpris2/mediaplayer2player.cpp

@@ -215,13 +215,21 @@ void MediaPlayer2Player::setPropertyPosition(int newPositionInMs)
 
     Q_EMIT Seeked(m_position);
 
-    QVariantMap parameters;
-    parameters.insert(QStringLiteral("progress-visible"), true);
-    parameters.insert(QStringLiteral("progress"), static_cast<double>(newPositionInMs) / m_audioPlayer->duration());
+    /* only sent new progress when it has advanced more than 1 %
+     * to limit DBus traffic
+     */
+    const auto incrementalProgress = static_cast<double>(newPositionInMs - mPreviousProgressPosition) / m_audioPlayer->duration();
+    if (incrementalProgress > 0.01 || incrementalProgress < 0)
+    {
+        mPreviousProgressPosition = newPositionInMs;
+        QVariantMap parameters;
+        parameters.insert(QStringLiteral("progress-visible"), true);
+        parameters.insert(QStringLiteral("progress"), static_cast<double>(newPositionInMs) / m_audioPlayer->duration());
 
-    mProgressIndicatorSignal.setArguments({QStringLiteral("application://org.kde.elisa.desktop"), parameters});
+        mProgressIndicatorSignal.setArguments({QStringLiteral("application://org.kde.elisa.desktop"), parameters});
 
-    QDBusConnection::sessionBus().send(mProgressIndicatorSignal);
+        QDBusConnection::sessionBus().send(mProgressIndicatorSignal);
+    }
 }
 
 double MediaPlayer2Player::Rate() const

src/mpris2/mediaplayer2player.h

@@ -163,6 +163,7 @@ private:
     ManageHeaderBar * m_manageHeaderBar = nullptr;
     AudioWrapper *m_audioPlayer = nullptr;
     mutable QDBusMessage mProgressIndicatorSignal;
+    int mPreviousProgressPosition = 0;
 };
 
 #endif // MEDIAPLAYER2PLAYER_H

[Ghost User]

This commit helped a lot in bringing down the CPU usage of plasmashell while Elisa is playing a song. However, plasmashell still consumes quite a bit of CPU, because line 216 (Q_EMIT Seeked(m_position);) is outside the if clause that was added by this commit. As such, Q_EMIT is still triggered a lot - even when the progress is less than 1% - and that induces load on the plasmashell. Why was it not moved inside the if clause like line 231 (QDBusConnection::sessionBus().send(mProgressIndicatorSignal);)?

[Nate Graham]

Seems like a sensible change. Would you be interested in submitting a merge request to do that? Thanks!