Re: Git commit generation numbers

Firstly, I presume the generation number would not form part of the
SHA1 calculation? No? Cool.

I suspect this may be where my suggestion falls down. Though I suspect
there is a case for object metadata which doesn't form part of the
SHA. Would generation number tampering be a concern?

Caching offers the ability to store that metadata, to provide the same
performance gain, but maintain the integrity of the SHA chain.
However, it does still leave the generation number liable to
tampering, meaning a generic non-SHA metadata solution might be
better.

TBH, there are few situations where historical generations are useful
- finding gen numbers of tags is one of them. Most cases are going to
be for new commits, and in that case, a few new commits at the tip of
each branch will very quickly reduce the number of traversals. What
use case would really create enough traversals that it should be a
performance concern?