I am trying to keep a counter for number of messages received per source ip in my kamailio script. 

The basic challenge is to keep this data in a neat structure.

Ideally, I want some array with keys named after source IP addresses,

sth like number_of_messages["10.10.10.10"] = 23

Of course, this data structure shall be script-persistent (as opposed to transaction persistent)

Is there any suggestion to do this? (keep a record of # of messages received from each source IP address and log them)?