Re: Dllist public/private part

"Mendola Gaetano" <mendola(at)bigfoot(dot)com> writes:
> I'm improving the Dllist in these direction:

AFAIR, catcache.c is the *only* remaining backend customer for Dllist,
and so any improvement for Dllist that breaks catcache is hardly an
improvement, no?

> 1) Avoid "if" statements in insertion/remove phase, for instance now the
> AddHeader appear like this:

<shrug> ... unless you can convert DLAddHead into a inline macro,
I doubt there'll be any visible performance difference.

> 2) Not using a malloc but using a "special" malloc that not perform
> a malloc for each request but do a BIG malloc at first request...

It would make more sense to migrate Dllist to use palloc. That's not
compatible with its use in frontend libpq; I've been speculating about
splitting off libpq to have a separate implementation instead of trying
to share code. I believe libpq only uses Dllist for the
pending-notify-events list, for which the code is poorly optimized
anyway (we don't need a doubly-linked list for that).

regards, tom lane