Re: [PATCH 2/2] refs.c: Write reflogs for notes just like for branch heads

On Tuesday 30 March 2010, Jeff King wrote:

On Mon, Mar 29, 2010 at 04:25:22PM +0200, Johan Herland wrote:

quoted

quoted

This is actually inspired by Jeff's novel notes use. I think
there are use cases where a notes log makes sense (notes on
commits) and those where it does not (metadata/textconv). In both
cases having a reflog is useful. So, the next step is really to
allow notes trees without history, which also takes care of the
pruning issue. I know how to do this, I just have to decide about
the configuration options.

I noticed that Jeff's proof-of-concept wrote notes trees without
making notes commits, and although it seemed like a bug at first,
it does - as you say - provide a rather nice way to store notes
trees without history.

No, it was very much intentional.

However, I think the next iteration will wrap the tree in an actual
commit, but just keep each commit parentless. That will provide a
nice spot for metadata like the cache validity information.

Agreed.

I like the idea of having a reflog, just because you could use it to
salvage an old cache if you were playing around with your helper's
options (or debugging your helper :) ). The usual 90-day expiration
time is perhaps too long, though.

Yes, 90 days as a default might be excessive, but you can always 
override it with a "git gc --prune=now"...

quoted

Note that I haven't explicitly designed the notes feature with this
in mind, so it's wise to add testcases for expected behaviour once
we start use history-less notes trees.

Thinking about it, the notes code itself (notes.h/.c) only wants a
notes _tree_ object, so will probably work fine with history-less
notes trees. But builtin/notes.c with its public commit_notes()
function may be another story...

I was planning on using my own cache-specific helper instead of
commit_notes() anyway, so that shouldn't be a problem. By using a
commit wrapper, I don't think any of the display code should be
confused (since they need to handle the case of a root note commit
anyway). Once I have some example trees, I can poke at them with the
existing notes code and see how they behave (and how we _want_ them
to behave, since I'm not sure yet what sort of cache introspection,
if any, would be useful).

Looking forward to your patches. :)


...Johan

-- 
Johan Herland, [off-list ref]
www.herland.net