On Sunday 07 February 2010, Jakub Narebski wrote:
> On Sat, 6 Feb 2010, Giuseppe Bilotta wrote:
> > On the other hand, as mentioned by Junio, this approach is not
> > future-proof enough for any kind of fan-out schemes.
>
> On the third hand ;-P you propose below a trick to deal with fan-out
> schemes, assuming that they use 2-character component breaking.
The current notes code (as it stands in 'pu') use only 2-character component
breaking, and I don't see any other fanout mechanism being added anytime
soon.
> Also, perhaps "git notes show" should acquire --batch / --batch-check
> options, similar to git-cat-file's options of the same name?
I'd much rather have support for ^{notes} (or similar) in the rev-parse
machinery, so that you could look up deadbeef's notes by passing
"deadbeef^{notes}" to 'git cat-file --batch'.
> > What worries me is that you're going to get fan-outs when there are
> > LOTS of notes, and that's precisely the kind of situation where you
> > _don't_ want to go through all the notes to pick the ones you're only
> > interested in.
>
> Right. This method would be contrary to the goals of fan-out schemes...
> well, we could use 'git ls-tree' without '-r' option, or simply
> 'git cat-file --batch' to read trees (note that we would get raw,
> unformatted tree, which is parseable with Perl, but it is not that easy),
> and go down level-by-level.
IMHO, it's much better/nicer to re-use the notes code for parsing note
trees. See above suggestion on deadbeef^{notes}.
> > If we have a guarantee that the fan-outs follow a 2/[2/...] scheme,
> > the open2 approach might still be the best way to go, by just trying
> > not only namespace:xxxxx...xxx but also namespace:xx/xxxxx etc.
> > Horrible, but could still be coalesced in a single call. It mgiht also
> > be optimized to stop at the first successfull hit in a namespace.
>
> Nice trick! It seems like quite a good idea... but it would absolutely
> require using 'git cat-file --batch' rather than one git-show per try.
Still, I'd still much rather use the notes.c code itself for doing this
since it should always be the fastest (not to mention future-proof) way of
making lookups in the notes tree.
...Johan
--
Johan Herland, <johan@xxxxxxxxxxx>
www.herland.net
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