[mapserver-dev] symbol lazy-loading

[thomas bonfort]

font files aren't loaded unless explicitely used in the map rendering.
lazy loading of images is on my todo-list with the rendering api (if only
because they are loaded through GD right now, and this would need to be
changed)

regards,

thomas

On Sat, Nov 21, 2009 at 17:03, Pavel Iacovlev <iacovlev.pavel at gmail.com>wrote:

> In my case I have a lot of symbols that are never used on render
> request because of 2 reasons:
> 1) There are a lot of layers(~20) and they need to be delivered in
> real time (so no tile cache or 1 wms request per layer) thats why all
> layers are rendered at server side as 1 image. Thats why I can't use
> multiple symbolsets.
> 2) An example of one of this layers is Fire hydrants, based on
> attributes I have 12 different types of them (12 images)
>
> I fully understand that my case is not common. Are there are ways to
> solve this problem not sacrificing a lot of performance like opening a
> lot images and font files on every request ? I think it's a nice
> example of what benefits we can is some cases from lazy-loading.
>
> On Sat, Nov 21, 2009 at 3:55 PM, thomas bonfort
> <thomas.bonfort at gmail.com> wrote:
> > Pavel,
> >
> > On Wed, Nov 18, 2009 at 13:24, Pavel Iacovlev <iacovlev.pavel at gmail.com>
> > wrote:
> >>
> >> Good day all,
> >>
> >> As I understood on render request mapserver loads all symbols into
> >> memory thats is fine if you have under 64 symbols (default limit).
> >
> >  recent versions of mapserver aren't limited to 64 symbols anymore.
> >
> >> I
> >> have a topographical map to render that maybe will have around 200+
> >> symbols and like 5-10 will be used per request. Maybe implementing
> >> lazy-loading (only then needed) for symbols will improve the
> >> performance ? and remove the cap at all.
> >
> > lazy loading of symbols would definitely make sense for image symbols,
> > although only for people with a single symbolset for multiple instances,
> as
> > otherwise the case is rarer to have defined  a symbol but never use it.
> >
> > the other symbol types wouldn't see much benefit from lazy loading imho,
> as
> > this is only a parser operation that has to be done anyways.
> >
> >>
> >> Another question is if I have
> >> 100 image symbols all 100 images are loaded into memory on render
> >> request ?
> >
> > yes, all the image files are loaded.
> >
> > regards,
> >
> > thomas
> >
> >
>
>
>
> --
> http://iap.md, The future is open
>
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