[Geotools-gt2-users] Streaming renderer: memory preloading considered harmful

[Andrea A. <and...@al...>]

Hi all,
as you may know, feature preloading in memory gives the streaming 
renderer the ability to
pre-load the features into a spatially indexed FeatureResults instance.
This speeds up visibly the rendering process, but there is a catch: it 
does not work :-)

Let me elaborate: memory preloading was a quick hack I made on a branch 
1.5 years ago
to check various options to speed up rendering. One was memory 
preloading, but I enabled
it only for one layer.
Right, you read it properly: it works only for one layer. If you add 
more layers to the
map, they won't show up.
Unfortunately someone ported this hack onto the trunk and 2.2.x branches 
without
noting the limitation.

For anybody using the 2.2.0 release, if you need speedier rendering 
please either do:
- use the shapefile renderer;
- preload features into the memory data store and then use it (it won't 
be as fast as
   the spatially indexed hack, but faster than loading from disk for sure).

Cheers
Andrea Aime