commit-graph: add '--reachable' option

When writing commit-graph files, it can be convenient to ask for all
reachable commits (starting at the ref set) in the resulting file. This
is particularly helpful when writing to stdin is complicated, such as a
future integration with 'git gc'.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index ea28bc311a..c7d0db5ab4 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -10,7 +10,7 @@ static char const * const builtin_commit_graph_usage[] = {
 	N_("git commit-graph [--object-dir <objdir>]"),
 	N_("git commit-graph read [--object-dir <objdir>]"),
 	N_("git commit-graph verify [--object-dir <objdir>]"),
-	N_("git commit-graph write [--object-dir <objdir>] [--append] [--stdin-packs|--stdin-commits]"),
+	N_("git commit-graph write [--object-dir <objdir>] [--append] [--reachable|--stdin-packs|--stdin-commits]"),
 	NULL
 };
 
@@ -25,12 +25,13 @@ static const char * const builtin_commit_graph_read_usage[] = {
 };
 
 static const char * const builtin_commit_graph_write_usage[] = {
-	N_("git commit-graph write [--object-dir <objdir>] [--append] [--stdin-packs|--stdin-commits]"),
+	N_("git commit-graph write [--object-dir <objdir>] [--append] [--reachable|--stdin-packs|--stdin-commits]"),
 	NULL
 };
 
 static struct opts_commit_graph {
 	const char *obj_dir;
+	int reachable;
 	int stdin_packs;
 	int stdin_commits;
 	int append;
@@ -127,6 +128,8 @@ static int graph_write(int argc, const char **argv)
 		OPT_STRING(0, "object-dir", &opts.obj_dir,
 			N_("dir"),
 			N_("The object directory to store the graph")),
+		OPT_BOOL(0, "reachable", &opts.reachable,
+			N_("start walk at all refs")),
 		OPT_BOOL(0, "stdin-packs", &opts.stdin_packs,
 			N_("scan pack-indexes listed by stdin for commits")),
 		OPT_BOOL(0, "stdin-commits", &opts.stdin_commits,
@@ -140,11 +143,16 @@ static int graph_write(int argc, const char **argv)
 			     builtin_commit_graph_write_options,
 			     builtin_commit_graph_write_usage, 0);
 
-	if (opts.stdin_packs && opts.stdin_commits)
-		die(_("cannot use both --stdin-commits and --stdin-packs"));
+	if (opts.reachable + opts.stdin_packs + opts.stdin_commits > 1)
+		die(_("use at most one of --reachable, --stdin-commits, or --stdin-packs"));
 	if (!opts.obj_dir)
 		opts.obj_dir = get_object_directory();
 
+	if (opts.reachable) {
+		write_commit_graph_reachable(opts.obj_dir, opts.append);
+		return 0;
+	}
+
 	string_list_init(&lines, 0);
 	if (opts.stdin_packs || opts.stdin_commits) {
 		struct strbuf buf = STRBUF_INIT;