On 04/03, Derrick Stolee wrote: > This is the first of several "small" patches that follow the serialized > Git commit graph patch (ds/commit-graph). > > As described in Documentation/technical/commit-graph.txt, the generation > number of a commit is one more than the maximum generation number among > its parents (trivially, a commit with no parents has generation number > one). Thanks for ensuring that this is defined and documented somewhere :) > > This series makes the computation of generation numbers part of the > commit-graph write process. > > Finally, generation numbers are used to order commits in the priority > queue in paint_down_to_common(). This allows a constant-time check in > queue_has_nonstale() instead of the previous linear-time check. > > This does not have a significant performance benefit in repositories > of normal size, but in the Windows repository, some merge-base > calculations improve from 3.1s to 2.9s. A modest speedup, but provides > an actual consumer of generation numbers as a starting point. > > A more substantial refactoring of revision.c is required before making > 'git log --graph' use generation numbers effectively. log --graph should benefit a lot more from this correct? I know we've talked a bit about negotiation and I wonder if these generation numbers should be able to help out a little bit with that some day. > > This patch series depends on v7 of ds/commit-graph. > > Derrick Stolee (6): > object.c: parse commit in graph first > commit: add generation number to struct commmit > commit-graph: compute generation numbers > commit: sort by generation number in paint_down_to_common() > commit.c: use generation number to stop merge-base walks > commit-graph.txt: update design doc with generation numbers > > Documentation/technical/commit-graph.txt | 7 +--- > alloc.c | 1 + > commit-graph.c | 48 +++++++++++++++++++++ > commit.c | 53 ++++++++++++++++++++---- > commit.h | 7 +++- > object.c | 4 +- > 6 files changed, 104 insertions(+), 16 deletions(-) > > -- > 2.17.0.20.g9f30ba16e1 > -- Brandon Williams
