Re: Deleting records while iterating through ldap_result

[Howard Chu <hyc@symas.com>]

Stephen wrote:
> Hi everyone,
>
> I'm using the C SDK and writing a program to prune old directory records.
>
> The core logic of the program could go something like this:-
>
> rc = ldap_search_ext( ld, ..<rest of parameters>  );
> while (!done) {
> 	rc = ldap_result( ld, ..<rest of parameters>,&searchResult) ;
> 	//Delete records matching criteria
> 	dn = ldap_get_dn( ld, searchResult );
>    	rc = ldap_delete_ext_s( ld, dn, ..<rest of parameters>);
> }
>
> -------
> I have two questions and they are probably related:-
>
> Firstly: Can I delete records while iterating through the results of the
> ldap search?

In general, yes. However, the order in which entries are returned is 
unspecified; if you're iterating through a subtree you may get a parent entry 
before a child, while you must delete the child before the parent.

> (In higher level languages deleting an item from a
> collection while navigating through a collection is often bad form. Is
> that the case here?)

RFC4511 doesn't say anything about this. It's probably 
implementation-dependent, but OpenLDAP has no issue with it.

> Secondly: Can I use the same session handle to delete the records as is
> used for the search? In the logic above, the session handle is ld, and
> ld is used for both the search and for the deletion.
> (I'm expecting I would need to use a different session handle for the
> logic above to work. Alternatively one could save all the records to be
> deleted in an array and then after the search loop, the same session
> handle can be used for all the deletes).

The API has no issue with this, but you may need to do the save anyway, due to 
ordering concerns.

--
  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/