On Mon, Feb 19, 2018 at 10:53 AM, Derrick Stolee [off-list ref] wrote:

        graph_name = write_commit_graph(opts.obj_dir);

        if (graph_name) {
                if (opts.set_latest)
                        set_latest_file(opts.obj_dir, graph_name);

+               if (opts.delete_expired)
+                       do_delete_expired(opts.obj_dir,
+                                         old_graph_name,
+                                         graph_name);
+

So this only allows to delete expired things and setting the latest
when writing a new graph. Would we ever envision a user to produce
a new graph (e.g. via obtaining a graph that they got from a server) and
then manually rerouting the latest to that new graph file without writing
that graph file in the same process? The same for expired.

I guess these operations are just available via editing the
latest or deleting files manually, which slightly contradicts
e.g. "git update-ref", which in olden times was just a fancy way
of rewriting the refs file manually. (though it claims to be less
prone to errors as it takes lock files)

 extern char *get_graph_latest_filename(const char *obj_dir);
+extern char *get_graph_latest_contents(const char *obj_dir);

Did
https://public-inbox.org/git/20180208213806.GA6381@sigill.intra.peff.net/
ever make it into tree? (It is sort of new, but I feel we'd want to
strive for consistency in the code base, eventually.)