Jim Wilcoxson wrote:
>
>
> The way I approach these things is to do a prototype in TCL using
> existing interfaces/functions, develop the whole application/page that
> will use it, and THEN if there is a performance problem, make sure
> that this thingy is the cause. Most of the time the bottleneck is
> not in something as low-level as reading the post data, but in loops,
> searching, DB queries, etc.
>
> Where we have found very HUGE bottlenecks are in using TCL string
> functions on large strings. TCL passes everything by value, so you
> end up copying this huge string (like 300K) every time it is
> referenced. A real performance killer.
sometimes judicious use of 'upvar' to do passing-by-reference
in tcl procs (instead of returning things in a return value)
can help in this regard. people find upvar distasteful for some reason
but it is useful sometimes to avoid some of the mega-string copies
that can occur as you mentioned above..
