Re: Which hash function to use, was Re: RFC: Another proposed hash function transition plan

Brandon Williams [off-list ref] writes:

quoted

It would make a whole of a lot of sense to make that knob not Boolean,
but to specify which hash function is in use.

100% agree on this point.  I believe the current plan is to have the
hashing function used for a repository be a repository format extension
which would be a value (most likely a string like 'sha1', 'sha256',
'black2', etc) stored in a repository's .git/config.  This way, upon
startup git will die or ignore a repository which uses a hashing
function which it does not recognize or does not compiled to handle.

I hope (and expect) that the end produce of this transition is a nice,
clean hashing API and interface with sufficient abstractions such that
if I wanted to switch to a different hashing function I would just need
to implement the interface with the new hashing function and ensure that
'verify_repository_format' allows the new function.

Yup.  I thought that part has already been agreed upon, but it is a
good thing that somebody is writing it down (perhaps "again", if not
"for the first time").

Thanks.