From: Junio C Hamano <gitster@pobox.com>
Date: Sat, 01 Oct 2011 20:41:45 GMT
Subject: Re: Git is not scalable with too many refs/*
Message-ID: <7vwrcola0m.fsf@alter.siamese.dyndns.org>
In-Reply-To: <201109301606.31748.mfick@codeaurora.org>

Martin Fick <mfick@codeaurora.org> writes:

> I guess this makes sense, we invalidate the cache and have 
> to rebuild it after every new ref is added?  Perhaps a 
> simple fix would be to move the invalidation right after all 
> the refs are updated?  Maybe write_ref_sha1 could take in a 
> flag to tell it to not invalidate the cache so that during 
> iterative updates it could be disabled and then run manually 
> after the update?

It might make sense, on top of Julian's patch, to add a bit that says "the
contents of this ref-array is current but the array is not sorted", and
whenever somebody runs add_ref(), append it also to the ref-array (so that
the contents do not have to be re-read from the filesystem) but flip the
"unsorted" bit on. Then update look-up and iteration to sort the array
when "unsorted" bit is on without re-reading the contents from the
filesystem.