[DGD] Re: Clones and very large arrays

[Erwin Harte]

On Fri, Apr 02, 2004 at 11:59:12PM +0000, Robert Forshaw wrote:
> What are the problems with having very large arrays? In my lib, every 
> master has an array containing a list of its clones. I expect the number of 
> clones for one particular object to be in the thousands, and potentially, 
> tens to hundreds of thousands. Are there any issues to be wary of with an 
> array of this size? Will it be CPU intensive to delete a single element in 
> an array of that size? (i.e. clones -= ({ 
> a_clone_that_has_just_been_destructed }) when sizeof(clones) > 100000).

It's not the CPU usage that will get you, but the fact that DGD has a
limit on array size lower than that.

>From dgd/src/config.c:

    { "array_size",         INT_CONST, FALSE, FALSE,
                            1, USHRT_MAX / 2 },

Assuming that an unsigned short is a 2 byte variable as it is on my
computer that means that array_size is a value between 1 and 32768.

> If this kind of use of arrays is deprecated, how should I keep a
> record of clones?

Michael gave you the solution that others (myself included) have been
using with a good amount of success.  You may want to wrap it into a
LWO so you don't have to see the ugly details, but that's about it. :)

Hope that helps,

Erwin.
-- 
Erwin Harte <harte at is-here.com>
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