commit-graph.c: show progress of finding reachable commits

When 'git commit-graph write --reachable' is invoked, the commit-graph
machinery calls 'for_each_ref()' to discover the set of reachable
commits.

Right now the 'add_ref_to_set' callback is not doing anything other than
adding an OID to the set of known-reachable OIDs. In a subsequent
commit, 'add_ref_to_set' will presumptively peel references. This
operation should be fast for repositories with an up-to-date
'$GIT_DIR/packed-refs', but may be slow in the general case.

So that it doesn't appear that 'git commit-graph write' is idling with
'--reachable' in the slow case, add a progress meter to provide some
output in the meantime.

In general, we don't expect a progress meter to appear at all, since
peeling references with a 'packed-refs' file is quick. If it's slow and
we do show a progress meter, the subsequent 'fill_oids_from_commits()'
will be fast, since all of the calls to
'lookup_commit_reference_gently()' will be no-ops.

Both progress meters are delayed, so it is unlikely that more than one
will appear. In either case, this intermediate state will go away in a
handful of patches, at which point there will be at most one progress
meter.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Taylor Blau 2020-05-13 15:59:33 -06:00 committed by Junio C Hamano
parent 1fe10844ca
commit d335ce8f24

View file

@ -1320,6 +1320,7 @@ static void compute_bloom_filters(struct write_commit_graph_context *ctx)
struct refs_cb_data {
struct oidset *commits;
struct progress *progress;
};
static int add_ref_to_set(const char *refname,
@ -1329,6 +1330,9 @@ static int add_ref_to_set(const char *refname,
struct refs_cb_data *data = (struct refs_cb_data *)cb_data;
oidset_insert(data->commits, oid);
display_progress(data->progress, oidset_size(data->commits));
return 0;
}
@ -1342,12 +1346,17 @@ int write_commit_graph_reachable(struct object_directory *odb,
memset(&data, 0, sizeof(data));
data.commits = &commits;
if (flags & COMMIT_GRAPH_WRITE_PROGRESS)
data.progress = start_delayed_progress(
_("Collecting referenced commits"), 0);
for_each_ref(add_ref_to_set, &data);
result = write_commit_graph(odb, NULL, &commits,
flags, split_opts);
oidset_clear(&commits);
if (data.progress)
stop_progress(&data.progress);
return result;
}