[postgis-devel] Common Code

[Bryce L Nordgren]

On Wed, Aug 10, 2011 at 9:35 AM, Mark Cave-Ayland <
mark.cave-ayland at siriusit.co.uk> wrote:

> Perhaps I've not explained it very well, but the use of a key/value store
> is related into the slightly hacky way in which we use the PostgreSQL memory
> contexts to handle context pointers and free themselves as part of the
> memory cleanup process. It's not a specifically a key/value store that we
> are looking for.
>

I think I'm not following. My understanding is that on the one hand (for
projections), we want to lookup a ProjPJ object based on an integer srid. On
the other hand (for prepped geoms/1d indices), we want to lookup a GEOSGeom
object given a LWGEOM. Regardless of memory management issues, how does one
avoid calling this a key/value store (or map or dictionary)? More
importantly for the purpose of a generic API, how does one compare keys
generically when they can sometimes be integers and sometimes LWGEOMs?

I withdraw the comment about depending on BerkeleyDB, as I've never used it
and it appears problematic. However, I think the fact that a utility a basic
as a generic key/value store cannot be easily located by google may speak to
the difficulty in writing one for C. We may just be stuck maintaining one
cache per key type...

Bryce
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-devel/attachments/20110810/54682d63/attachment.html>