On Mon, Feb 26, 2018 at 6:32 PM, Derrick Stolee [off-list ref] wrote:

This patch series is another big difference from version 4, but I do
think we are converging on a stable design.

This series depends on a few things in flight:

* jt/binsearch-with-fanout for bsearch_graph()

* 'master' includes the sha1file -> hashfile rename in (98a3beab).

* [PATCH] commit: drop uses of get_cached_commit_buffer(). [1] I
  couldn't find a ds/* branch for this one, but it is necessary or
  else the commit graph test script should fail.

'jk/cached-commit-buffer', 'jk' as the first commit in that series
is by Jeff King ?

I found this commit by searching for its verbatim title in
'git log --oneline origin/pu' and then using
https://github.com/mhagger/git-when-merged
to find 51ff16f5f3a (Merge branch 'jk/cached-commit-buffer'
into jch, 2018-02-23)

Here are some of the inter-patch changes:

* The single commit graph file is stored in the fixed filename
  .git/objects/info/commit-graph

* Because of this change, I struggled with the right way to pair the
  lockfile API with the hashfile API. Perhaps they were not meant to
  interact like this. I include a new patch step that adds a flag for
  hashclose() to keep the file descriptor open so commit_lock_file()
  can succeed. Please let me know if this is the wrong approach.

This sounds like an interesting thing to review.

* A side-benefit of this change is that the "--set-latest" and
  "--delete-expired" arguments are no longer useful.

* I re-ran the performance tests since I rebased onto master. I had
  moved my "master" branch on my copy of Linux from another perf test,
  which changed the data shape a bit.

* There was some confusion between v3 and v4 about whether commits in
  an existing commit-graph file are automatically added to the new
  file during a write. I think I cleared up all of the documentation
  that referenced this to the new behavior: we only include commits
  reachable from the starting commits (depending on --stdin-commits,
  --stdin-packs, or neither) unless the new "--additive" argument
  is specified.

Thanks,
Stefan