On 18 October 2010 01:19, Tom Lane <t...@sss.pgh.pa.us> wrote: > Brendan Jurd <dire...@gmail.com> writes: >> On 17 October 2010 09:59, Tom Lane <t...@sss.pgh.pa.us> wrote: >>> Good point. Maybe the correct fix is to remember whether each token was >>> quoted or not, so that keyword detection can be done safely after the >>> initial lexing. I still think that the current method is impossibly >>> ugly ... > >> I'm happy to revise the patch on that basis. Any suggestions about >> how to communicate the 'quotedness' of each token? We could make each >> token a struct consisting of the token itself, plus a boolean flag to >> indicate whether it had been quoted. Does that work for you? > > Seems reasonable. I had the idea of a parallel list of booleans in the > back of my mind, but a list of structs is probably easier to understand, > and to extend further if necessary. >
Okay, I've taken the red pill and I'm finding out how deep the rabbit hole goes ... The logical structure of pg_hba.conf is a set of lines, each line containing a set of fields, each field containing a set of tokens. The way the existing implementation handles this is to create a list of lines containing sublists of fields, containing comma-separated strings for the set of tokens, with newlines embedded next to tokens which might be keywords. The tokeniser breaks apart the comma-separated tokens ... and then reassembles them into a comma-separated string. Which the db/role matching functions then have to break apart *again*. In order to keep track of whether each individual token was quoted, I first need to impose some sanity here. Rather than using a magical string for each field, I intend to use a List of HbaToken structs which explicitly note whether quoting was used. Introducing an extra List level does mean a bit more work copying and freeing, and it makes the patch really quite intrusive. I have to touch a lot of lines in hba.c, but I think the additional clarity is worth it. If nobody dissuades me from this approach I hope to post a patch in a couple of days. Cheers, BJ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers