RFC-24: published implementation proposal on bugzilla

[Sean Gillies]

Umberto Nicoletti wrote:
> I have been working on an example implementation of rfc-24 and the
> fruit of my labor is attachment #632 to:
> http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=2032
> 
> Direct link:
> http://mapserver.gis.umn.edu/bugs/attachment.cgi?id=632&action=view
> 
> Apply this patch to cvs HEAD to see how rfc24 would be implemented.
> The patch only modifies the map and layer objects, the rest is still unmodified.
> 
> Key points:
> 1. refactor map->layers to be an array of pointers instead of a array of structs
> 2. allocation of a new layerObj only happens when needed, thus conserving memory
> (allowing for large values of MAX_NUM_LAYERS with minimal waste of memory)
> 3. wrap map->layers access with GET_LAYER macros to ease future developments
> (i.e. removal of MAX_NUM_LAYERS)
> 4. check that layer->map is not null before using it and raise a new
> error if it is (MS_NULLPARENTERR)
> 5. reference counter for mapObj and layerObj
> 6. modification of mapserver core and swig interface files to do reference
> counting for map and layers (incr and decr)
> 7. created unit tests for python (mapscript/python/tests/cases/refcount.py) to
> test the functionality of the previous items. This has not been added to
> runtests.py yet
> 
> Due to the large extent of the changes I have also made available
> items 1,2,3 and item 4 available as two separate patches.
> 
> Happy hacking and tell me what you think,
> Umberto
> 

Hi Umberto,

I'll give it a try. My hat is off to you.

Cheers,
Sean