Subject: [PATCH 2/6] commit-graph write: add more progress output

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Tue, 20 Nov 2018 15:04:39 +0000

Add more progress output to the output already added in
7b0f229222 ("commit-graph write: add progress output", 2018-09-17).

As noted in that commit most of the progress output isn't displayed on
small repositories, but before this change we'd noticeably hang for
2-3 seconds at the end on medium sized repositories such as linux.git.

Now we'll instead show output like this, and have no human-observable
point at which we're not producing progress output:

    $ ~/g/git/git --exec-path=$HOME/g/git commit-graph write
    Finding commits for commit graph: 6418991, done.
    Computing commit graph generation numbers: 100% (797205/797205), done.
    Writing out commit graph chunks: 2399861, done.

This "graph chunks" number is not meant to be meaningful to the user,
but just to show that we're doing work and the command isn't
hanging.

On a much larger in-house repository I have we'll show (note how we
also say "Annotating[...]"):

    $ ~/g/git/git --exec-path=$HOME/g/git commit-graph write
    Finding commits for commit graph: 48271163, done.
    Annotating commit graph: 21424536, done.
    Computing commit graph generation numbers: 100% (7141512/7141512), done.
    Writing out commit graph chunks: 21424913, done.

Signed-off-by: Ævar Arnfjörð Bjarmason <[email-masked]>
---
 commit-graph.c | 47 ++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 38 insertions(+), 9 deletions(-)

diff --git a/commit-graph.c b/commit-graph.c
index e6d0d7722b..afce20dd4d 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -433,7 +433,9 @@ struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit
 
 static void write_graph_chunk_fanout(struct hashfile *f,
 				     struct commit **commits,
-				     int nr_commits)
+				     int nr_commits,
+				     struct progress *progress,
+				     uint64_t *progress_cnt)
 {
 	int i, count = 0;
 	struct commit **list = commits;
@@ -445,6 +447,8 @@ static void write_graph_chunk_fanout(struct hashfile *f,
 	 */
 	for (i = 0; i < 256; i++) {
 		while (count < nr_commits) {
+			if (progress)
+				display_progress(progress, ++*progress_cnt);
 			if ((*list)->object.oid.hash[0] != i)
 				break;
 			count++;
@@ -456,12 +460,17 @@ static void write_graph_chunk_fanout(struct hashfile *f,
 }
 
 static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
-				   struct commit **commits, int nr_commits)
+				   struct commit **commits, int nr_commits,
+				   struct progress *progress,
+				   uint64_t *progress_cnt)
 {
 	struct commit **list = commits;
 	int count;
-	for (count = 0; count < nr_commits; count++, list++)
+	for (count = 0; count < nr_commits; count++, list++) {
+		if (progress)
+			display_progress(progress, ++*progress_cnt);
 		hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
+	}
 }
 
 static const unsigned char *commit_to_sha1(size_t index, void *table)
@@ -471,7 +480,9 @@ static const unsigned char *commit_to_sha1(size_t index, void *table)
 }
 
 static void write_graph_chunk_data(struct hashfile *f, int hash_len,
-				   struct commit **commits, int nr_commits)
+				   struct commit **commits, int nr_commits,
+				   struct progress *progress,
+				   uint64_t *progress_cnt)
 {
 	struct commit **list = commits;
 	struct commit **last = commits + nr_commits;
@@ -482,6 +493,9 @@ static void write_graph_chunk_data(struct hashfile *f, int hash_len,
 		int edge_value;
 		uint32_t packedDate[2];
 
+		if (progress)
+			display_progress(progress, ++*progress_cnt);
+
 		parse_commit(*list);
 		hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
 
@@ -542,7 +556,9 @@ static void write_graph_chunk_data(struct hashfile *f, int hash_len,
 
 static void write_graph_chunk_large_edges(struct hashfile *f,
 					  struct commit **commits,
-					  int nr_commits)
+					  int nr_commits,
+					  struct progress *progress,
+					  uint64_t *progress_cnt)
 {
 	struct commit **list = commits;
 	struct commit **last = commits + nr_commits;
@@ -566,6 +582,9 @@ static void write_graph_chunk_large_edges(struct hashfile *f,
 						  nr_commits,
 						  commit_to_sha1);
 
+			if (progress)
+				display_progress(progress, ++*progress_cnt);
+
 			if (edge_value < 0)
 				edge_value = GRAPH_PARENT_MISSING;
 			else if (!parent->next)
@@ -764,6 +783,7 @@ void write_commit_graph(const char *obj_dir,
 	int num_extra_edges;
 	struct commit_list *parent;
 	struct progress *progress = NULL;
+	uint64_t progress_cnt;
 
 	if (!commit_graph_compatible(the_repository))
 		return;
@@ -937,10 +957,19 @@ void write_commit_graph(const char *obj_dir,
 		hashwrite(f, chunk_write, 12);
 	}
 
-	write_graph_chunk_fanout(f, commits.list, commits.nr);
-	write_graph_chunk_oids(f, GRAPH_OID_LEN, commits.list, commits.nr);
-	write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr);
-	write_graph_chunk_large_edges(f, commits.list, commits.nr);
+	if (report_progress)
+		progress = start_delayed_progress(
+			_("Writing out commit graph chunks"),
+			progress_cnt = 0);
+	write_graph_chunk_fanout(f, commits.list, commits.nr, progress,
+				 &progress_cnt);
+	write_graph_chunk_oids(f, GRAPH_OID_LEN, commits.list, commits.nr,
+			       progress, &progress_cnt);
+	write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr,
+			       progress, &progress_cnt);
+	write_graph_chunk_large_edges(f, commits.list, commits.nr, progress,
+				      &progress_cnt);
+	stop_progress(&progress);
 
 	close_commit_graph(the_repository);
 	finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
-- 
2.20.0.rc0.387.gc7a69e6b6c