iRule as stored function or similar

Hi,

thanks for everything everyone's said here. I've updated my one single iRule to store data in an array using the virtual name as the array key:

  when RULE_INIT {
     number of times an ip address can be used between lookups
    set ::max_usage_count 3
  
     array of resolved ip addresses
    array set ::server_ipaddr { }
     array of resolved address uses
    array set ::usage_count { }
    log local0. "Completed RULE_INIT on lookup"
  }
  when CLIENT_ACCEPTED {
     initialize usage count if not yet done for this VS
    if { [ info exists ::usage_count([virtual name]) ] == 0 } {
      set ::usage_count([virtual name]) 0
    }
    
     use server_ipaddr if it exists, use dummy localhost if not
    if { [ info exists ::server_ipaddr([virtual name]) ] == 1 } {
      node $::server_ipaddr([virtual name]) [getfield [virtual name] "_" 3]
    } else {
       this WILL fail, but only occurs on very first usage when no IP address is known yet.
      node 127.0.0.1
    }
    
     decrement usage_count for this virtual server
    incr ::usage_count([virtual name]) -1
     call lookup if maximum usages has happened and reset usage counter
    if { $::usage_count([virtual name]) <= 0 } {
      set ::usage_count([virtual name]) $::max_usage_count
      NAME::lookup [getfield [virtual name] "_" 2]
    }
  }
  when NAME_RESOLVED {
     assign resolved name to server_ipaddr array
    if {[scan [NAME::response] "%d.%d.%d.%d" a b c d] == 4 } {
      set ::server_ipaddr([virtual name]) [NAME::response]
    }
  } 

I realised that as i already wanted to put the destination server and port number in the virtual server name, i could just split on an underscore (e.g. vs_example.com_443) to get all the configuration details i needed. I can then store additional dunamic data in two global arrays as i go along.

I'm very happy with the logic here, but wonder about the optimization of it all. I've read tips that advise against intermediate local variable names (otherwise i would have been tempted to copy [virtual name] to a local variable in the CLIENT_ACCEPTED event) but if anyone has other pointers to tweak the efficieny, every little helps. i'm doing a lot of repeated array lookups and getfields... i'm lead to believe that's the best approach if anything though.

Cheers

Chris