[PATCH] WMS plugin drawing extremely slow

[singularita]

When I use WMS plugin and add new layer in zoom about 12m, then zoom to about 23m and start doing things (drawing things, moving the view around), then the responsiveness is very slow (the view is redrawn only 3-4 times/second, too little for any comfortable work)

If I hide the WMS layer, everything is fast suddenly, so the cause must be in the WMS.

I have Core 2 Quad q6600, 8 GB ram, Geforce 8800 GTX (512MB VRAM), Windows XP 64bit and 64bit Java (1.6.0-10beta), so I think the performance should be decent on that configuration...

I use -Xmx1024m when running JOSM

[singularita]

I think I have discovered possible cause. When I deleted contents of WMS cache directory (there were about 700 files) while JOSM was still running, things immediately started to be fluent again. Could the cache be the cause for slowness?

[xeen]

Hmm… can you have a look how much memory is used when WMS is activated? A slow file system might be the cause if images need to to be loaded from disk (i.e. while moving). After images are cached in memory, it should be fast though, especially while drawing there shouldn't be any lag. Can you verify if it really lags while driving without moving?

Also, have a look how large the cache directory was when there are 700 files. Will have a look into it.

[xeen]

Confirmed on Win XP. It looks like the filesystem gets very slow with a lot of files. I need to rework the cache system anyway, so I'm going to fix this on the way.

[xeen]

I still couldn't find the time to put it into a real core class that other plugins may use as well. This is meant as an intermediate fix to make WMS more user friendly. Fixes #2310 (this one), #2307 (blank tiles) and probably #2350 (null pointer exception)

[stoecker]

​[o15091].