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>

Taylor Blau committed May 13, 2020 at 15:59 UTC d335ce8f24e335ffda911f01a9569f7132e64cdb

1 file changed +9

commit-graph.c

@@ -1320,6 +1320,7 @@ static void compute_bloom_filters(struct write_commit_graph_context *ctx)

1320

1321 struct refs_cb_data {

1322 struct oidset *commits;

1323 + struct progress *progress;

1324 };

1325

1326 static int add_ref_to_set(const char *refname,

@@ -1329,6 +1330,9 @@ static int add_ref_to_set(const char *refname,

1330 struct refs_cb_data *data = (struct refs_cb_data *)cb_data;

1331

1332 oidset_insert(data->commits, oid);

1333 +

1334 + display_progress(data->progress, oidset_size(data->commits));

1335 +

1336 return 0;

1337 }

1338

@@ -1342,12 +1346,17 @@ int write_commit_graph_reachable(struct object_directory *odb,

1346

1347 memset(&data, 0, sizeof(data));

1348 data.commits = &commits;

1349 + if (flags & COMMIT_GRAPH_WRITE_PROGRESS)

1350 + data.progress = start_delayed_progress(

1351 + _("Collecting referenced commits"), 0);

1352

1353 for_each_ref(add_ref_to_set, &data);

1354 result = write_commit_graph(odb, NULL, &commits,

1355 flags, split_opts);

1356

1357 oidset_clear(&commits);

1358 + if (data.progress)

1359 + stop_progress(&data.progress);

1360 return result;

1361 }

1362