On Wed, Apr 04, 2018 at 02:53:45PM -0400, Derrick Stolee wrote: > > I'd have to do some timings, but I suspect we may want to switch to the > > "tag --contains" algorithm anyway. This still does N independent > > merge-base operations, one per ref. So with enough refs, you're still > > better off throwing it all into one big traversal. > > ...and I suppose your timings are to find out if there are data shapes where > the branch algorithm is faster. Perhaps that is impossible now that we have > the generation number cutoff for the tag algorithm.
Well, I wanted to show the opposite: that the branch algorithm can still perform quite poorly. :) I think with generation numbers that the tag algorithm should always perform better, since you can't walk past a merge base when using a cutoff. But it could definitely perform worse in a case where you don't have generation numbers. > Patches 7 and 8 seem to me like simple changes with no downside UNLESS we > are deciding instead to delete the code I'm changing. Yeah, I think they are strict improvements modulo the inverted UNDEF logic I mentioned. -Peff
