[PATCH v2 4/6] commit-graph write: add more describing progress output

[Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>]

Make the progress output shown when we're searching for commits to
include in the graph more descriptive. This amends code I added in
7b0f229222 ("commit-graph write: add progress output", 2018-09-17).

Now, on linux.git, we'll emit this sort of output in the various modes
we support:

    $ git commit-graph write
    Finding commits for commit graph among packed objects: 100% (6365492/6365492), done.
    [...]

    # Actually we don't emit this since this takes almost no time at
    # all. But if we did (s/_delayed//) we'd show:
    $ git for-each-ref --format='%(objectname)' | git commit-graph write --stdin-commits
    Finding commits for commit graph from 584 refs: 100% (584/584), done.
    [...]

    $ (cd .git/objects/pack/ && ls *idx) | git commit-graph write --stdin-pack
    Finding commits for commit graph in 3 packs: 6365492, done.
    [...]

The middle on of those is going to be the output users might see in
practice, since it'll be emitted when they get the commit graph via
gc.writeCommitGraph=true. But as noted above you need a really large
number of refs for this message to show. It'll show up on a test
repository I have with ~165k refs:

    Finding commits for commit graph from 165203 refs: 100% (165203/165203), done.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
 commit-graph.c | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/commit-graph.c b/commit-graph.c
index 7c1afa4704..fd1fd61750 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -779,6 +779,7 @@ void write_commit_graph(const char *obj_dir,
 	struct progress *progress = NULL;
 	uint64_t progress_cnt = 0;
 	unsigned long approx_nr_objects;
+	struct strbuf progress_title = STRBUF_INIT;
 
 	if (!commit_graph_compatible(the_repository))
 		return;
@@ -815,8 +816,12 @@ void write_commit_graph(const char *obj_dir,
 		strbuf_addf(&packname, "%s/pack/", obj_dir);
 		dirlen = packname.len;
 		if (report_progress) {
-			oids.progress = start_delayed_progress(
-				_("Finding commits for commit graph"), 0);
+			strbuf_addf(&progress_title,
+				    Q_("Finding commits for commit graph in %d pack",
+				       "Finding commits for commit graph in %d packs",
+				       pack_indexes->nr),
+				    pack_indexes->nr);
+			oids.progress = start_delayed_progress(progress_title.buf, 0);
 			oids.progress_done = 0;
 		}
 		for (i = 0; i < pack_indexes->nr; i++) {
@@ -833,14 +838,20 @@ void write_commit_graph(const char *obj_dir,
 			free(p);
 		}
 		stop_progress(&oids.progress);
+		strbuf_reset(&progress_title);
 		strbuf_release(&packname);
 	}
 
 	if (commit_hex) {
-		if (report_progress)
-			progress = start_delayed_progress(
-				_("Finding commits for commit graph"),
-				commit_hex->nr);
+		if (report_progress) {
+			strbuf_addf(&progress_title,
+				    Q_("Finding commits for commit graph from %d ref",
+				       "Finding commits for commit graph from %d refs",
+				       commit_hex->nr),
+				    commit_hex->nr);
+			progress = start_delayed_progress(progress_title.buf,
+							  commit_hex->nr);
+		}
 		for (i = 0; i < commit_hex->nr; i++) {
 			const char *end;
 			struct object_id oid;
@@ -860,12 +871,13 @@ void write_commit_graph(const char *obj_dir,
 			}
 		}
 		stop_progress(&progress);
+		strbuf_reset(&progress_title);
 	}
 
 	if (!pack_indexes && !commit_hex) {
 		if (report_progress)
 			oids.progress = start_delayed_progress(
-				_("Finding commits for commit graph"),
+				_("Finding commits for commit graph among packed objects"),
 				approx_nr_objects);
 		for_each_packed_object(add_packed_commits, &oids, 0);
 		if (oids.progress_done < approx_nr_objects)
@@ -970,6 +982,8 @@ void write_commit_graph(const char *obj_dir,
 				      &progress_cnt);
 	stop_progress(&progress);
 
+	strbuf_release(&progress_title);
+
 	close_commit_graph(the_repository);
 	finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
 	commit_lock_file(&lk);
-- 
2.20.0.rc0.387.gc7a69e6b6c