Re: Including object type and size in object id (Re: Git Merge contributor summit notes)

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 26, 2018, 22:40 UTC
Message-ID: <xmqq7epybgvh.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20180326210039.GB21735@aiede.svl.corp.google.com>

Jonathan Nieder <jrnieder@gmail.com> writes:

Show 6 quoted lines

> This implies a limit on the object size (e.g. 5 bytes in your
> example).  What happens when someone wants to encode an object larger
> than that limit?
>
> This also decreases the number of bits available for the hash, but
> that shouldn't be a big issue.

I actually thought that the latter "downside" makes the object name a tad larger.

But let's not go there, really.

"X is handy if we can get it on the surface without looking into it" will grow. Somebody may want to have the generation number of a commit in the commit object name. Yet another somebody may want to be able to quickly learn the object name for the top-level tree from the commit object name alone. We need to stop somewhere, and as already suggested in the thread(s), having auxiliary look-up table is a better way to go, encoding nothing in the name, as we are going to need such a look-up table because it is unrealistic to encode everything we would want in the name anyway.