MarkerClustererPlus memory leak when hiding clusters

Question

I've got 4 different types of markers on single map. Currently a slideshow rotates through each type, hiding the other 3. There is a MarkerClusterer object for each different type of marker so that they do not cluster together.

The issue I am having is that the heap snapshot in chrome shows I'm increasing the amount of memory in use by about 2mb every 5 minutes or so. This is my code currently:

function transitionMarkers() {
    if (isSlideShowActive) {
        for (var i = 0; i < markers.length; i++) {
            if (nutrientsArray[slideShowCounter] === markers[i].address.SOURCE_GROUP) {
                markers[i].setVisible(true);
            } else {
                markers[i].setVisible(false);
            }
        }
        for (var n in types.NUTRIENTS) {
            for (var sc in types.SOURCE_CODES) {
                if (nutrientsArray[slideShowCounter] === n) {
                    markerClusters[n][sc].setMap(map);
                } else {
                    markerClusters[n][sc].setMap(null);
                }
            }
        }
    }
    incrementSlideShowCounter();
}

Markers have the ability to change their visibility, and since they will be re-rendered within a minute, I don't bother using setMap(null) on them. However, marker clusters do not have this option. When I examine the heap snapshot, I see thousands of objects that look like this:

[1076] :: pf @2451465 5 360 % 2 3360 %
b :: gi @2273271 2 120 % 170 5441 %
e :: function() @2454527 6 360 % 2 3000 %
proto :: pf @2338839 5 120 % 360 %
d :: "bounds_changed" @67519

It looks like there are thousands of these bounds_changed events sitting there accumulating...my map only hides or shows markers, it doesn't move around, zoom in or out, or anything like that.

Any thoughts?

Answer 1

These bounds_changed-events will be bound to the map when a ClusterIcon will be added(happens all the time when you call markerClusters[n][sc].setMap(map)).

When you call markerClusters[n][sc].setMap(null) the ClusterIcons will be removed, the onRemove-method also clears all listeners bound to the ClusterIcon-instances, but the onRemove-method does not remove the bounds_changed-events bound to the map(you may call it a bug).

So you may either fix the bug on your own and modify the markerclusterer.js so that it also removes the bounds_changed-event, or don't call setMap() at all, instead you may e.g. call the methods show() or hide() of the ClusterIcon-instances to show or hide them(should give a better performance).