Messages in this thread | | | Subject | Re: [RFC] B+Tree library V2 | From | Johannes Berg <> | Date | Thu, 08 Jan 2009 17:34:10 +0100 |
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On Thu, 2009-01-08 at 17:24 +0100, Jörn Engel wrote:
> > Alright, back to this. I'm going to need something like the patch below > > (except the update facility, which I thought I needed but then changed > > my mind) which is on top of your patch. Does that look sane? > > At first glance it does. The update looks like someone might need it, > but doesn't have a user yet. The btree_merge is similar, as I used to > need it, but no longer do. Maybe #if 0 those two.
Sure, works for me. I just had written it and didn't want to keep it from the world after changing my mind about needing it.
> Well, I used to have heaps of btrees around and wanted to share the > mempool between all of them. Not sure if I still do, I believe not. > Will check. > > If mempools aren't shared, I agree that encapsulating those bits is much > nicer.
Just made the API a bit quirky, maybe just support both ways of using things? Would only need a flag somewhere in the btree structure, I'd think; ultimately it doesn't matter much to me though.
> > Another thing that I need is a visitor that deletes _some_ entries. How > > can I do that? Additionally, it would be nice to be able to abort a tree > > walk, when you have determined that you can't continue for whatever > > reason. > > If you want to open-code it, you can use btree_lookup_less(). I added > that function sometime last month. Basically something like this: > key = btree_last(head, geo); > while (key) { > /* do something with key */ > key = btree_lookup_less(head, geo, key); > } > > Maybe it should be renamed to btree_get_prev_key(). I never noticed how > confusing it was because my head was busy with other problems. The code > is currently burried within my logfs tree: > http://logfs.org/git?p=logfs;a=summary
I don't think I've understood this yet. That code above there is a backwards walk over the key space, and it's safe to call btree_remove(key) at /* do something with key */?
> Will merge it with your patch and respin later tonight or tomorrow...
Cool, thanks. Mainly making it a module for testing anyway.
johannes [unhandled content-type:application/pgp-signature] | |