[Users] Serial forking

[Bogdan-Andrei Iancu]

Hi Tim,


Tim Klein wrote:

> Bogdan said:
>
>> I just committed serial proper forking support into core - it was 
>> migrated from LCR module. I mean proper, since it has q value support 
>> and it can be used by any module without any inter-module dependencies.
>>
>> The idea behind was to allow to all module that performs parallel 
>> forking to do also serial forking - exec, enum, registrar, etc.
>
>
> That's good news!  Thank you!
>
> But I have some questions to help me understand the new functions. 
> Please see below...
>
>> There are two new script functions :
>>     *serialize_branches(n)* : it inherits the functionality of 
>> load_contacts() from LCR; gets all parallel branches and convert them 
>> into AVPs for serial forking; numerical parameter 'n' says if any 
>> previous AVP should be removed (if non-0) or not (if 0). Returns true 
>> is no error (even if no serialization happened).
>>     *next_branches()* : it inherits the functionality of 
>> next_contacts() from LCR; get (based on q value) the next contact(s) 
>> to be used in  sequential forking. Returns true only if a new contact 
>> was got to be used.
>>
>> The AVP containing the branches is accessible only via alias - its ID 
>> is not configurable or visible; the alias (automatically exported by 
>> core) is "serial_branch" - it is visible from any module that uses 
>> the avp core aliasing system.
>
>
> My questions:
>
> Let's say there are 4 contacts registered.  Two of the contacts ("A" 
> and "B") have q value of 1.0.  The other two contacts ("C" and "D") 
> have q value of 0.5.
>
> Using the following routing script, which contacts will be tried in 
> the main route block, and which will be tried in the failure_route block?
>
according to RFC and Q interpretation, you will get in request route the 
C and D contacts (as they have the lower q (higher priority) and their q 
is equal. In failure route you get A and B (as they have the same q).

regards,
bogdan

>       modparam("registrar", "append_branches", 1)
>       .....
>       {
>          .....
>          lookup("location");
>          serialize_branches(1);
>          t_on_failure("1");
>          t_relay();
>       }
>
>       failure_route[1] {
>          if (next_branches()) {
>              t_relay();
>          }
>       }
>
>
> Thank you!
>
> Tim
>
>