dynamic groups

[MichaÅ SzulczyÅski <michal.szulczynski@altkom.pl>]

Hello,

My name is MichaÅ SzulczyÅski, and I'm a student at Warszawska WyÅsza
SzkoÅa Informatyki in Poland. I'm on a practice at the company where
Aleksander Adamowski works.
As he said, I will try to implement dynamic list member 'caching'. The
general idea is to "materialize" the member attribute of the dynamic
group using existing static attribute values infrastructure (including
indexes) and update them automatically when there is a
add/modify/modrdn/delete operation on an object that matches the dynlist
memberURL filter. 

The operation of dynlist overlay would be identical as it is now without
specifying an additional dynlist configuration option.

The plan is to, depending on the additional, optional dynlist-attrset
configuration parameter, grab the dynamic list entries for that dynlist
configuration from the database, and put them into a memory-resident
list (which would hold all the dynamic groups that we are interested in,
ie. the ones with the additional configuration option set). 
When there is a add/mod/modrdn/delete operation on any entry, we would
check this list for a matching dynlist filter, and add/modify/delete the
member attribute of the dynamic list for that entry. Much like a static
group, but with automated addition/deletion to/from it, effectively
making it a dynamic group. Manual updates to the member attribute would
be prevented and would raise an error.

First, in addition to dynlist_info_t we would need to hold the pointer
to our memory-resident dynamic group list per dynlist overlay instance.
That's for speed optimization, since searching for all dynamic lists on
each update operation would have a huge performance impact.
As we can only hold only one backend-specific config data in
Operation->o_bd->bd_info->on_bi.bi_private, we wold need to hold both
pointers (dynlist_info_t and the pointer to our list) in an additional
struct, and store that. But this method would mean changing much of the
existing codebase, and I don't know if that would be good.
If there would be another place where we could store the pointer to the
dynamic group list, that would be better.

Second, I would like to know if there is a function to test whether one
DN is contained in another DN (i.e. one DN is a descendant to another
DN).
I need this to compare the base DN of the dynamic group, and the
added/modified/deleted/modrdn'ed entry (eg: if the entry DN
<uid=test,l=City,ou=People,o=MyOrg> is in the dynamic group's member
URL's base DN <ou=People,o=MyOrg>). I think that comparing the
normalized DN's stringwise backwards from the strings' end would work,
but I'm not sure.

Third:
* can we do an add-or-replace with BackendDB->be_modify
* when doing a LDAP_MOD_DELETE on a single attribute's value can we
ignore a case where that attribute value does not exist in the entry (so
we can avoid checking for its presence and save an unnecessary read
operation)?



--
MichaÅ SzulczyÅski
    Praktykant
    Altkom Akademia S.A. http://www.altkom.pl
    Warszawa, ul. ChÅodna 51
    
    

SÄd Rejonowy dla m.st. Warszawy w Warszawie, XII WydziaÅ Gospodarczy Krajowego Rejestru SÄdowego,
KRS: 0000120139, NIP 118-00-08-391, KapitaÅ zakÅadowy: 1000 000 PLN.  Adres rejestrowy Firmy - ul. Stawki 2, 00-193 Warszawa.
Niniejsza wiadomoÅÄ zawiera informacje zastrzeÅone i stanowiÄce tajemnicÄ przedsiÄbiorstwa firmy Altkom Akademia S.A.
Ujawnianie tych informacji osobom trzecim lub nieuprawnione wykorzystanie ich do wÅasnych celÃw jest zabronione.
JeÅeli otrzymaliÅcie PaÅstwo niniejszÄ wiadomoÅÄ omyÅkowo, prosimy o niezwÅoczne skontaktowanie siÄ z nadawcÄ oraz usuniÄcie wszelkich kopii niniejszej wiadomoÅci.
This message contains proprietary information and trade secrets of Altkom Akademia S.A. company.
Unauthorized use or disclosure of this information to any third party is prohibited.
If you received this message by mistake, please contact the sender immediately and delete all copies of this message.