Reuse applets list for Windowed Widgets runner

This caused a lot of CPU load, because the applets were listed and filtered for each letter typed. Now they are only listed when the match() method is called for the first time and reused for the rest of the match session.

runners/windowedwidgets/windowedwidgetsrunner.cpp

@@ -30,6 +30,7 @@
 
 #include <Plasma/Applet>
 #include <Plasma/PluginLoader>
+#include <QMutexLocker>
 
 K_EXPORT_PLASMA_RUNNER_WITH_JSON(WindowedWidgetsRunner, "plasma-runner-windowedwidgets.json")
 
@@ -42,6 +43,7 @@ WindowedWidgetsRunner::WindowedWidgetsRunner(QObject *parent, const QVariantList
     addSyntax(Plasma::RunnerSyntax(QStringLiteral(":q:"), i18n("Finds Plasma widgets whose name or description match :q:")));
     addSyntax(Plasma::RunnerSyntax(i18nc("Note this is a KRunner keyword", "mobile applications"), i18n("list all Plasma widgets that can run as standalone applications")));
     setMinLetterCount(3);
+    connect(this, &AbstractRunner::teardown, this, [this](){ m_applets.clear(); });
 }
 
 WindowedWidgetsRunner::~WindowedWidgetsRunner()
@@ -50,28 +52,22 @@ WindowedWidgetsRunner::~WindowedWidgetsRunner()
 
 void WindowedWidgetsRunner::match(Plasma::RunnerContext &context)
 {
+    loadMetadataList();
     const QString term = context.query();
     QList<Plasma::QueryMatch> matches;
 
-    const auto &listMetadata =  Plasma::PluginLoader::self()->listAppletMetaData(QString());
-    for (const KPluginMetaData &md : listMetadata) {
-        if (!md.isValid()) {
-            continue;
-        }
-
+    for (const KPluginMetaData &md : qAsConst(m_applets)) {
         if (((md.name().contains(term, Qt::CaseInsensitive) ||
              md.value(QLatin1String("GenericName")).contains(term, Qt::CaseInsensitive) ||
              md.description().contains(term, Qt::CaseInsensitive)) ||
              md.category().contains(term, Qt::CaseInsensitive) ||
-             term.startsWith(i18nc("Note this is a KRunner keyword", "mobile applications"))) &&
-             !md.rawData().value(QStringLiteral("NoDisplay")).toBool()) {
-
-            if (!md.rawData().value(QStringLiteral("X-Plasma-StandAloneApp")).toBool()) {
-                continue;
-            }
+             term.startsWith(i18nc("Note this is a KRunner keyword", "mobile applications")))) {
 
             Plasma::QueryMatch match(this);
-            setupMatch(md, match);
+            match.setText(md.name());
+            match.setSubtext(md.description());
+            match.setIconName(md.iconName());
+            match.setData(md.pluginId());
             if (md.name().compare(term, Qt::CaseInsensitive) == 0) {
                 match.setType(Plasma::QueryMatch::ExactMatch);
                 match.setRelevance(1);
@@ -96,14 +92,6 @@ void WindowedWidgetsRunner::run(const Plasma::RunnerContext &context, const Plas
     QProcess::startDetached(QStringLiteral("plasmawindowed"), {match.data().toString()});
 }
 
-void WindowedWidgetsRunner::setupMatch(const KPluginMetaData &md, Plasma::QueryMatch &match)
-{
-    match.setText(md.name());
-    match.setSubtext(md.description());
-    match.setIconName(md.iconName());
-    match.setData(md.pluginId());
-}
-
 QMimeData * WindowedWidgetsRunner::mimeDataForMatch(const Plasma::QueryMatch &match)
 {
     QMimeData *data = new QMimeData();
@@ -111,6 +99,23 @@ QMimeData * WindowedWidgetsRunner::mimeDataForMatch(const Plasma::QueryMatch &ma
     return data;
 }
 
+void WindowedWidgetsRunner::loadMetadataList()
+{
+    // We call this method in the match thread
+    QMutexLocker locker(&m_mutex);
+    // If the entries have already been loaded we reuse them for the same session
+    if (!m_applets.isEmpty()) {
+        return;
+    }
+    const auto &listMetadata =  Plasma::PluginLoader::self()->listAppletMetaData(QString());
+    for (const KPluginMetaData &md : listMetadata) {
+        if (md.isValid()
+            && !md.rawData().value(QStringLiteral("NoDisplay")).toBool()
+            && !md.rawData().value(QStringLiteral("X-Plasma-StandAloneApp")).toBool()) {
+            m_applets << md;
+        }
+    }
+}
 
 #include "windowedwidgetsrunner.moc"
 

runners/windowedwidgets/windowedwidgetsrunner.h

@@ -22,6 +22,7 @@
 
 
 #include <KService>
+#include <QMutex>
 
 #include <krunner/abstractrunner.h>
 
@@ -45,10 +46,10 @@ public:
 
 protected Q_SLOTS:
     QMimeData * mimeDataForMatch(const Plasma::QueryMatch &match) override;
-
-
-protected:
-    void setupMatch(const KPluginMetaData &md, Plasma::QueryMatch &action);
+private:
+    void loadMetadataList();
+    QList<KPluginMetaData> m_applets;
+    QMutex m_mutex;
 };
 
 #endif