Low JOSM performance when mapillary layer is active with large sequence

[wiktorn]

When I download larger area and work with Mapillary layer I observe lower performance of scrolling/panning and drawing. After short profiling session I observed a lot of calls to:
MapillaryImage.equals(...)

I identified following source of this calls:
*while painting the layer there is iteration over sequences. But MapillarySequence.next(...) calls ArrayList.contains(...), which is O(n), as well as ArrayList.indexOf(...), which is also O(n), and in the end - calls MapillaryImage.equals(...) * n (length of sequence)

My guess is, that if you'd have constant-time MapillaryAbstractImage.next(...) this would improve performance dramatically.

[nokutu]

I see... Then I'll try to improve it. I don't have much time at the moment so I will probably do this and a couple of other bugfixes during christmas holidays.

Thanks

[wiktorn]

Example gpx, where you can see performance problems

[nokutu]

I've changed the ArrayList by Sets created by using:

Set<Foo> set = Collections.newSetFromMap(new ConcurrentHashMap<Foo, Boolean>);

Therefore, performance with big sets should be significantly improved.