Re: Git commit generation numbers

On Fri, Jul 15, 2011 at 2:17 PM, Linus Torvalds
[off-list ref] wrote:

For example, for the "git tag --contains" thing, what's the
performance effect of just skipping tags that are much older than the
commit we ask for?

Hmm.

Maybe there is something seriously wrong with this trivial patch, but
it gave the right results for the test-cases I threw at it, and passes
the tests.

Before:

   [torvalds@i5 linux]$ time git tag --contains v2.6.24 > correct

   real	0m7.548s
   user	0m7.344s
   sys	0m0.116s

After:

   [torvalds@i5 linux]$ time ~/git/git tag --contains v2.6.24 > date-cut-off

   real	0m0.161s
   user	0m0.140s
   sys	0m0.016s

and 'correct' and 'date-cut-off' both give the same answer.

The date-based "slop" thing is (at least *meant* to be - note the lack
of any extensive testing) "at least five consecutive commits that have
dates that are more than five days off".

Somebody should double-check my logic. Maybe I'm doing something
stupid. Because that's a *big* difference.

                     Linus