John Naylor <john.naylor@enterprisedb.com> writes:
> On Mon, Dec 5, 2022 at 9:33 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> IMV these are absolutely private to bitmapset.c. I reject the idea
>> that they should be exposed publicly, under these names or any others.
> Well, they've already escaped to tidbitmap.c as a copy. How do you feel
> about going that route?
Not terribly pleased with that either, I must admit.
>> Maybe we need some more bitmapset primitive functions? What is it
>> you actually want to accomplish in the end?
> for (idx = 0; idx < WORDNUM(128); idx++)
BITS_PER_BITMAPWORD is already public, so can't you spell that
for (idx = 0; idx < 128/BITS_PER_BITMAPWORD; idx++)
> slotpos += bmw_rightmost_one_pos(inverse);
I'm not terribly against exposing bmw_rightmost_one_pos, given
that it's just exposing the pg_rightmost_one_posXX variant that
matches BITS_PER_BITMAPWORD.
> isset[idx] |= RIGHTMOST_ONE(inverse);
And RIGHTMOST_ONE is something that could be made public, but
I think it belongs in pg_bitutils.h, perhaps with a different
name.
> ...which, if it were reversed so that a set bit meant "available", would
> essentially be bms_first_member(), so a more primitive version of that
> might work.
That could be a reasonable direction to pursue as well.
regards, tom lane