commit-graph write: add more descriptive progress output

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% (6529159/6529159), 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 630 refs: 100% (630/630), done.
    [...]

    $ (cd .git/objects/pack/ && ls *idx) | git commit-graph write --stdin-pack
    Finding commits for commit graph in 3 packs: 6529159, 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@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 18 insertions, 7 deletions

diff --git a/commit-graph.c b/commit-graph.c
index 3124dfae13..936119b1f9 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -822,8 +822,12 @@ 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++) {
@@ -841,14 +845,20 @@ 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;
@@ -868,12 +878,13 @@ 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,
 				       FOR_EACH_OBJECT_PACK_ORDER);