Re: [exim] Idea: Predefined macros

Philip Hazel wrote:
> On Wed, 2 May 2007, Magnus Holmgren wrote:
>
>> I don't think there would be any practical differences except in rather
>> complex configurations. Still, probably something for Exim 5.
>
> Yes. The current arrangement was intended as a *simple* macro feature.
>

Fair 'nuf.

Now .. if I undertstand all this correctly, at each load (of many..) each MACRO
found is searched for in every line of the configure file.

Whether the line in which is found will be 'active' as the smtp session proceeds
is irrelevant. IOW a MACRO coudl eist in the configure file a dozen times, yet
not be called in one session of a hundred.

So *either* many MACRO's *or* many lines increases the work required -
regardless of what sort of acl's are actually triggered by the traffic.

(Complex MACRO's with dynamics yet another story...)

But one might then ask, how MACRO's compare in potential load with:

- hostlists

- lookups (in general)

- lookups involving SQL calls

Correct me if I am wrong, but I am under the impressions that a 'hostlist' is
handled much as the described parsing for a MACRO, i.e. - end-to-end expansion &
substitution, called on or not...

- while a 'lookup' - be it file, db, or SQL - is ignored until actually
encountered in acl that *uses* it, IOW, skipped in many cases.

Corrections, please?

Bill Hacker