receive-pack: convert update hooks to new API

Use the new hook sideband API introduced in the previous commit.

The hook API avoids creating a custom struct child_process and other
internal hook plumbing (e.g. calling find_hook()) and prepares for
the specification of hooks via configs or running parallel hooks.

Execution is still sequential through the current hook.[ch] via the
run_process_parallel_opts.processes=1 arg.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: nasamuffin

builtin/receive-pack.c

@@ -918,6 +918,16 @@ static int feed_receive_hook(void *state_, const char **bufp, size_t *sizep)
 	return 0;
 }
 
+static void hook_output_to_sideband(struct strbuf *output, void *cb_data UNUSED)
+{
+	if (!output)
+		BUG("output must be non-NULL");
+
+	/* buffer might be empty for keepalives */
+	if (output->len)
+		send_sideband(1, 2, output->buf, output->len, use_sideband);
+}
+
 static int run_receive_hook(struct command *commands,
 			    const char *hook_name,
 			    int skip_broken,
@@ -941,29 +951,18 @@ static int run_receive_hook(struct command *commands,
 
 static int run_update_hook(struct command *cmd)
 {
-	struct child_process proc = CHILD_PROCESS_INIT;
-	int code;
-	const char *hook_path = find_hook(the_repository, "update");
-
-	if (!hook_path)
-		return 0;
-
-	strvec_push(&proc.args, hook_path);
-	strvec_push(&proc.args, cmd->ref_name);
-	strvec_push(&proc.args, oid_to_hex(&cmd->old_oid));
-	strvec_push(&proc.args, oid_to_hex(&cmd->new_oid));
+	struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;
 
-	proc.no_stdin = 1;
-	proc.stdout_to_stderr = 1;
-	proc.err = use_sideband ? -1 : 0;
-	proc.trace2_hook_name = "update";
+	strvec_pushl(&opt.args,
+		     cmd->ref_name,
+		     oid_to_hex(&cmd->old_oid),
+		     oid_to_hex(&cmd->new_oid),
+		     NULL);
 
-	code = start_command(&proc);
-	if (code)
-		return code;
 	if (use_sideband)
-		copy_to_sideband(proc.err, -1, NULL);
-	return finish_command(&proc);
+		opt.consume_output = hook_output_to_sideband;
+
+	return run_hooks_opt(the_repository, "update", &opt);
 }
 
 static struct command *find_command_by_refname(struct command *list,
@@ -1640,33 +1639,20 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 static void run_update_post_hook(struct command *commands)
 {
 	struct command *cmd;
-	struct child_process proc = CHILD_PROCESS_INIT;
-	const char *hook;
-
-	hook = find_hook(the_repository, "post-update");
-	if (!hook)
-		return;
+	struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;
 
 	for (cmd = commands; cmd; cmd = cmd->next) {
 		if (cmd->error_string || cmd->did_not_exist)
 			continue;
-		if (!proc.args.nr)
-			strvec_push(&proc.args, hook);
-		strvec_push(&proc.args, cmd->ref_name);
+		strvec_push(&opt.args, cmd->ref_name);
 	}
-	if (!proc.args.nr)
+	if (!opt.args.nr)
 		return;
 
-	proc.no_stdin = 1;
-	proc.stdout_to_stderr = 1;
-	proc.err = use_sideband ? -1 : 0;
-	proc.trace2_hook_name = "post-update";
+	if (use_sideband)
+		opt.consume_output = hook_output_to_sideband;
 
-	if (!start_command(&proc)) {
-		if (use_sideband)
-			copy_to_sideband(proc.err, -1, NULL);
-		finish_command(&proc);
-	}
+	run_hooks_opt(the_repository, "post-update", &opt);
 }
 
 static void check_aliased_update_internal(struct command *cmd,