Re: [RFC PATCH 00/18] Multi-pack index (MIDX)

On Mon, Jan 08 2018, Derrick Stolee jotted:

On 1/7/2018 5:42 PM, Ævar Arnfjörð Bjarmason wrote:

quoted

If something cares about both throughput and e.g. is saving the
abbreviated SHA-1s isn't it better off picking some arbitrary size
(e.g. --abbrev=20), after all the default abbreviation is going to show
something as small as possible, which may soon become ambigous after the
next commit.

Unfortunately, with the way the abbreviation algorithms work, using
--abbrev=20 will have similar performance problems because you still
need to inspect all packfiles to ensure there isn't a collision in the
first 20 hex characters.

I meant (but forgot to write) that this would be some new mode,
e.g. --abbrev=20 --no-abbrev-check which would just perform a substr()
of the 40 character SHA-1. It might be interesting to add that for
reasons completely unrelated to your series.

Thanks for answering the rest.