[sr-dev] Implementation question / usrloc / registrar

[Carsten Bock]

Hi everyone,

just a short request for comments:
Similar to the dialog-variables, which i implemented in my IMS branch
recently, i need something similar for usrloc. Basically, i need to
store additional data to a registration; which i can access after
"lookup()" or upon a "is_registered()" call. Basically:

$reg_var(test) = "some value";
save();
- - -
lookup();
xlog("reg_var(test) is $reg_var(test)\n");

Now there are different approaches:
1) implement this funtionality in usrloc/registrar directly (similar
to my dialog-pvar-implementation). The performance when doing this
impact should be minor if not used, since simply an empty pointer
would be carried along every registration. This would be the cleanest
way to do this; but however since many people are using usrloc i have
a little respect doing changes on such core-module. Maybe it could be
implemented as a change in usrloc and a dedicated module just for
getting and setting the values.
2) another way would be to implement this in a dedicated module. This
would mean, that i would not touch usrloc module and it would of
course have no impact on "regular" usrloc usage at all if not used. I
would have to add a second list of in-memory values, which would have
to be synched with db, a second timer to do so. The list would be
dependent on the usrloc callbacks. There is always the danger
data-inconsistency.
3) is there any way, to do this with some event-routes,
shared-variables or something similar?

Any thoughts?
Comments very welcome!

Kind regards,
Carsten

P.S.: If i do not receive any comments, i would implement the first
approach (directly in usrloc/registrar) in my IMS-branch for later
merging into master.