[PATCH v4 3/4] batch check whether submodule needs pushing into one call

[Heiko Voigt <hvoigt@hvoigt.net>]

We run a command for each sha1 change in a submodule. This is
unnecessary since we can simply batch all sha1's we want to check into
one command. Lets do it so we can speedup the check when many submodule
changes are in need of checking.

Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>
---
 submodule.c | 62 ++++++++++++++++++++++++++++++++-----------------------------
 1 file changed, 33 insertions(+), 29 deletions(-)

diff --git a/submodule.c b/submodule.c
index 12ac1ea..11391fa 100644
--- a/submodule.c
+++ b/submodule.c
@@ -507,27 +507,49 @@ static int append_sha1_to_argv(const unsigned char sha1[20], void *data)
 	return 0;
 }
 
-static int submodule_needs_pushing(const char *path, const unsigned char sha1[20])
+static int check_has_commit(const unsigned char sha1[20], void *data)
 {
-	if (add_submodule_odb(path) || !lookup_commit_reference(sha1))
+	int *has_commit = data;
+
+	if (!lookup_commit_reference(sha1))
+		*has_commit = 0;
+
+	return 0;
+}
+
+static int submodule_has_commits(const char *path, struct sha1_array *commits)
+{
+	int has_commit = 1;
+
+	if (add_submodule_odb(path))
+		return 0;
+
+	sha1_array_for_each_unique(commits, check_has_commit, &has_commit);
+	return has_commit;
+}
+
+static int submodule_needs_pushing(const char *path, struct sha1_array *commits)
+{
+	if (!submodule_has_commits(path, commits))
 		return 0;
 
 	if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 		struct child_process cp = CHILD_PROCESS_INIT;
-		const char *argv[] = {"rev-list", NULL, "--not", "--remotes", "-n", "1" , NULL};
 		struct strbuf buf = STRBUF_INIT;
 		int needs_pushing = 0;
 
-		argv[1] = sha1_to_hex(sha1);
-		cp.argv = argv;
+		argv_array_push(&cp.args, "rev-list");
+		sha1_array_for_each_unique(commits, append_sha1_to_argv, &cp.args);
+		argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
+
 		prepare_submodule_repo_env(&cp.env_array);
 		cp.git_cmd = 1;
 		cp.no_stdin = 1;
 		cp.out = -1;
 		cp.dir = path;
 		if (start_command(&cp))
-			die("Could not run 'git rev-list %s --not --remotes -n 1' command in submodule %s",
-				sha1_to_hex(sha1), path);
+			die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
+					path);
 		if (strbuf_read(&buf, cp.out, 41))
 			needs_pushing = 1;
 		finish_command(&cp);
@@ -582,22 +604,6 @@ static void find_unpushed_submodule_commits(struct commit *commit,
 	diff_tree_combined_merge(commit, 1, &rev);
 }
 
-struct collect_submodule_from_sha1s_data {
-	char *submodule_path;
-	struct string_list *needs_pushing;
-};
-
-static int collect_submodules_from_sha1s(const unsigned char sha1[20],
-		void *data)
-{
-	struct collect_submodule_from_sha1s_data *me = data;
-
-	if (submodule_needs_pushing(me->submodule_path, sha1))
-		string_list_insert(me->needs_pushing, me->submodule_path);
-
-	return 0;
-}
-
 static void free_submodules_sha1s(struct string_list *submodules)
 {
 	struct string_list_item *item;
@@ -634,12 +640,10 @@ int find_unpushed_submodules(struct sha1_array *commits,
 	argv_array_clear(&argv);
 
 	for_each_string_list_item(submodule, &submodules) {
-		struct collect_submodule_from_sha1s_data data;
-		data.submodule_path = submodule->string;
-		data.needs_pushing = needs_pushing;
-		sha1_array_for_each_unique((struct sha1_array *) submodule->util,
-				collect_submodules_from_sha1s,
-				&data);
+		struct sha1_array *commits = (struct sha1_array *) submodule->util;
+
+		if (submodule_needs_pushing(submodule->string, commits))
+			string_list_insert(needs_pushing, submodule->string);
 	}
 	free_submodules_sha1s(&submodules);
 
-- 
2.10.1.386.gc503e45