Indexing revisited

[Howard Chu <hyc@symas.com>]

A few thoughts occurred to me today about our indexing code:
  1) we compute a hash preset for each invocation, crunching the syntax and 
matching rule's OID, among other things. (It used to be worse, we used to 
recompute this for each individual value, even though it's a constant.) 
There's no need to always recompute this on each invocation, we can compute it 
once at first usage and reuse that result. It should speed up index 
generation, particularly on smaller attribute values. I'm preparing a patch to 
test this now.
  2) using this precomputed hash, we can drop the syntax, mr, and prefix 
arguments from the indexer function signature. That will also speed things up.
  3) I note that the 'use' argument is also never used in our indexer 
functions. Will drop this as well.

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