[mapguide-internals] RFC required for tile caching changes?

[Paul Spencer]

Chris,

This is probably beyond the scope of what you would like to do, but  
it does involve cache optimization.  Imagine I have a bunch of really  
good data (say NavTeq for example) and I've built up a library of  
layer styling that I really like.  I want to use these layers as a  
tiled layer in several applications that need different  
MapDefinitions but all share the same base tile layer.  It would be  
really nice if the cache for each map could point to a common  
location for the tiles.

As you are already re-jigging the tiling mechanism, is there a way  
that you could incorporate this kind of flexibility?

Cheers

Paul

On 12-Jan-07, at 1:39 PM, Chris Claydon wrote:

> We have found that problems can occur if too many cached tile  
> images are
> stored in a single folder on the hard drive. For this reason, I have
> some changes to submit that ensure that we only store 900 tiles per
> folder (in 30 x 30 blocks).
>
> This changes the locations of stored tiles, by introducing new
> subfolders, and will thus "orphan" any tiles already created by the
> cache. Since the root folder for the tiles for any given map will not
> change, these orphaned tiles will be cleaned up if the user  
> modifies the
> map definition or makes a call to the Clear(MgMap* map) method in the
> tile service API. The user could also force the cleanup simply by
> deleting the contents of the root cache folder when they upgrade to  
> the
> version containing these changes.
>
> I'd like to treat this submission as a simple defect fix, but the
> requirement for the extra cleanup steps may indicate that an RFC is
> required, and I'd like to know the opinions of the PSC on this matter.
>
> Also, please let me know if you require any further information about
> this submission.
>
> Cheers,
>
> Chris Claydon.
>
> _______________________________________________
> mapguide-internals mailing list
> mapguide-internals at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapguide-internals

+-----------------------------------------------------------------+
|Paul Spencer                          pspencer at dmsolutions.ca    |
+-----------------------------------------------------------------+
|Chief Technology Officer                                         |
|DM Solutions Group Inc                http://www.dmsolutions.ca/ |
+-----------------------------------------------------------------+