schedule a rect cache sync when stuff gets in

do a disc sync with a 2 minutes delay

src/plasma/private/theme_p.cpp

@@ -69,10 +69,16 @@ ThemePrivate::ThemePrivate(QObject *parent)
     ThemeConfig config;
     cacheTheme = config.cacheTheme();
 
-    saveTimer = new QTimer(this);
+    pixmapSaveTimer = new QTimer(this);
-    saveTimer->setSingleShot(true);
+    pixmapSaveTimer->setSingleShot(true);
-    saveTimer->setInterval(600);
+    pixmapSaveTimer->setInterval(600);
-    QObject::connect(saveTimer, SIGNAL(timeout()), this, SLOT(scheduledCacheUpdate()));
+    QObject::connect(pixmapSaveTimer, SIGNAL(timeout()), this, SLOT(scheduledCacheUpdate()));
+
+    rectSaveTimer = new QTimer(this);
+    rectSaveTimer->setSingleShot(true);
+    //2 minutes
+    rectSaveTimer->setInterval(2 * 60 * 1000);
+    QObject::connect(rectSaveTimer, SIGNAL(timeout()), this, SLOT(saveSvgElementsCache()));
 
     updateNotificationTimer = new QTimer(this);
     updateNotificationTimer->setSingleShot(true);
@@ -290,7 +296,7 @@ void ThemePrivate::discardCache(CacheTypes caches)
 {
     if (caches & PixmapCache) {
         pixmapsToCache.clear();
-        saveTimer->stop();
+        pixmapSaveTimer->stop();
         if (pixmapCache) {
             pixmapCache->clear();
         }
@@ -465,6 +471,21 @@ void ThemePrivate::settingsChanged(bool emitChanges)
     setThemeName(cg.readEntry("name", ThemePrivate::defaultTheme), false, emitChanges);
 }
 
+void ThemePrivate::saveSvgElementsCache()
+{
+    if (svgElementsCache) {
+        QHashIterator<QString, QSet<QString> > it(invalidElements);
+        while (it.hasNext()) {
+            it.next();
+            KConfigGroup imageGroup(svgElementsCache, it.key());
+            imageGroup.writeEntry("invalidElements", it.value().toList()); //FIXME: add QSet support to KConfig
+        }
+
+        //Pretty drastic, but this is executed only very rarely
+        svgElementsCache->sync();
+    }
+}
+
 QColor ThemePrivate::color(Theme::ColorRole role) const
 {
     switch (role) {

src/plasma/private/theme_p.h

@@ -94,6 +94,7 @@ public Q_SLOTS:
     void onAppExitCleanup();
     void notifyOfChanged();
     void settingsChanged(bool emitChanges);
+    void saveSvgElementsCache();
 
 Q_SIGNALS:
     void themeChanged();
@@ -134,7 +135,8 @@ public:
     QHash<QString, QString> idsToCache;
     QHash<styles, QString> cachedStyleSheets;
     QHash<QString, QString> discoveries;
-    QTimer *saveTimer;
+    QTimer *pixmapSaveTimer;
+    QTimer *rectSaveTimer;
     QTimer *updateNotificationTimer;
     unsigned cacheSize;
     CacheTypes cachesToDiscard;

src/plasma/theme.cpp

@@ -91,17 +91,7 @@ Theme::Theme(const QString &themeName, QObject *parent)
 
 Theme::~Theme()
 {
-    if (d->svgElementsCache) {
+    d->saveSvgElementsCache();
-        QHashIterator<QString, QSet<QString> > it(d->invalidElements);
-        while (it.hasNext()) {
-            it.next();
-            KConfigGroup imageGroup(d->svgElementsCache, it.key());
-            imageGroup.writeEntry("invalidElements", it.value().toList()); //FIXME: add QSet support to KConfig
-        }
-
-        //The application is probably dying, last occasion to write to disk
-        d->svgElementsCache->sync();
-    }
 
     if (d == ThemePrivate::globalTheme) {
         if (!ThemePrivate::globalThemeRefCount.deref()) {
@@ -346,8 +336,8 @@ void Theme::insertIntoCache(const QString &key, const QPixmap &pix, const QStrin
         d->keysToCache.insert(key, id);
         d->idsToCache.insert(id, key);
 
-        //always start timer in d->saveTimer's thread
+        //always start timer in d->pixmapSaveTimer's thread
-        QMetaObject::invokeMethod(d->saveTimer, "start", Qt::QueuedConnection);
+        QMetaObject::invokeMethod(d->pixmapSaveTimer, "start", Qt::QueuedConnection);
     }
 }
 
@@ -428,6 +418,8 @@ void Theme::insertIntoRectsCache(const QString &image, const QString &element, c
             it.value().insert(element);
         }
     }
+
+    d->rectSaveTimer->start();
 }
 
 void Theme::invalidateRectsCache(const QString &image)