Attila Csipa wrote:
>
> On Thursday 27 March 2003 18:21, Daniel Morissette wrote:
> > > #define MS_MAXLAYERS 1000 /* maximum number of layers in a map file */
> > Is this really an intentional change? This can have a quite significant
> > impact on memory usage.
>
> While we are at it, I'd like to ask why isn't this solved ina semi-dynamic way
> ? We all know that the issue of insufficient layer/class space keeps popping
> up in the lists, but I'm not sure why it has to be done this way.
>
> If there has been a discussion about this I'm sorry for bringing it up again.
>
> If I'm correct the problem is here:
>
> int initMap(mapObj *map)
> {
> map->numlayers = 0;
> if((map->layers = (layerObj *)malloc(sizeof(layerObj)*MS_MAXLAYERS)) ==
> NULL) {
> msSetError(MS_MEMERR, NULL, "initMap()");
> return(-1);
> }
> ...
>
> So if MAXLAYERS is high, we're mallocing huge amounts of data. My question is,
> why is this better then mallocing a fixed amount (which would be, say, the
> current MS_MAXLAYERS value), and then when/if we fill up this space just do a
> realloc on a new layer init (this could be done by duplicating allocated
> space and not simply increasing so overhead of both processing and memory
> would not be significant). This way there would be only a memory limit on the
> number of layers and classes, while the loss of speed would be insignificant
> (advanced users could still change the initial number of layers, in which
> case there would be practically no slowdown).
>
> Regards,
> Attila
