[PATCH v2 13/22] run-command API: make run_process_parallel{,_tr2}() thin wrappers

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Make the "run_process_parallel()" and "run_process_parallel_tr2()"
functions thin wrappers that construct a "struct
run_process_parallel_opts" struct, this is in preparation for changing
the API users to use a "struct run_process_parallel_opts" directly.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 run-command.c | 66 ++++++++++++++++++++++++++++++++++-----------------
 run-command.h |  7 ++++++
 2 files changed, 51 insertions(+), 22 deletions(-)

diff --git a/run-command.c b/run-command.c
index 3042cb26172..3cdf85876c1 100644
--- a/run-command.c
+++ b/run-command.c
@@ -1766,36 +1766,30 @@ static int pp_collect_finished(struct parallel_processes *pp)
 	return result;
 }
 
-void run_processes_parallel(size_t processes,
-			    get_next_task_fn get_next_task,
-			    start_failure_fn start_failure,
-			    task_finished_fn task_finished,
-			    void *pp_cb)
+static void run_processes_parallel_1(const struct run_process_parallel_opts *opts, void *pp_cb)
 {
 	int code;
 	int output_timeout = 100;
 	int spawn_cap = 4;
 	struct parallel_processes pp = {
-		.max_processes = processes,
+		.max_processes = opts->processes,
 		.data = pp_cb,
 		.buffered_output = STRBUF_INIT,
 		.ungroup = run_processes_parallel_ungroup,
 	};
-	const struct run_process_parallel_opts opts = {
-		.processes = processes,
-
-		.get_next_task = get_next_task,
-		.start_failure = start_failure,
-		.task_finished = task_finished,
-
-		.ungroup = run_processes_parallel_ungroup,
-	};
+	/* options */
+	const char *tr2_category = opts->tr2_category;
+	const char *tr2_label = opts->tr2_label;
+	const int do_trace2 = tr2_category && tr2_label;
 
 	/* unset for the next API user */
 	run_processes_parallel_ungroup = 0;
 
-	pp_init(&pp, &opts);
+	if (do_trace2)
+		trace2_region_enter_printf(tr2_category, tr2_label, NULL,
+					   "max:%d", opts->processes);
 
+	pp_init(&pp, opts);
 	while (1) {
 		for (int i = 0;
 		    i < spawn_cap && !pp.shutdown &&
@@ -1812,7 +1806,7 @@ void run_processes_parallel(size_t processes,
 		}
 		if (!pp.nr_processes)
 			break;
-		if (opts.ungroup) {
+		if (opts->ungroup) {
 			for (size_t i = 0; i < pp.max_processes; i++)
 				pp.children[i].state = GIT_CP_WAIT_CLEANUP;
 		} else {
@@ -1828,19 +1822,47 @@ void run_processes_parallel(size_t processes,
 	}
 
 	pp_cleanup(&pp);
+
+	if (do_trace2)
+		trace2_region_leave(tr2_category, tr2_label, NULL);
+}
+
+void run_processes_parallel(size_t processes,
+			    get_next_task_fn get_next_task,
+			    start_failure_fn start_failure,
+			    task_finished_fn task_finished,
+			    void *pp_cb)
+{
+	const struct run_process_parallel_opts opts = {
+		.processes = processes,
+		.ungroup = run_processes_parallel_ungroup,
+
+		.get_next_task = get_next_task,
+		.start_failure = start_failure,
+		.task_finished = task_finished,
+	};
+
+	run_processes_parallel_1(&opts, pp_cb);
 }
 
-void run_processes_parallel_tr2(size_t n, get_next_task_fn get_next_task,
+void run_processes_parallel_tr2(size_t processes, get_next_task_fn get_next_task,
 				start_failure_fn start_failure,
 				task_finished_fn task_finished, void *pp_cb,
 				const char *tr2_category, const char *tr2_label)
 {
-	trace2_region_enter_printf(tr2_category, tr2_label, NULL, "max:%d", n);
+	const struct run_process_parallel_opts opts = {
+		.tr2_category = tr2_category,
+		.tr2_label = tr2_label,
+
+		.processes = processes,
+		.ungroup = run_processes_parallel_ungroup,
 
-	run_processes_parallel(n, get_next_task, start_failure,
-			       task_finished, pp_cb);
+		.get_next_task = get_next_task,
+		.start_failure = start_failure,
+		.task_finished = task_finished,
+	};
 
-	trace2_region_leave(tr2_category, tr2_label, NULL);
+	run_processes_parallel_1(&opts, pp_cb);
 }
 
 int run_auto_maintenance(int quiet)
diff --git a/run-command.h b/run-command.h
index 03be48e7ce3..bd0b7b70b27 100644
--- a/run-command.h
+++ b/run-command.h
@@ -464,6 +464,13 @@ typedef int (*task_finished_fn)(int result,
  */
 struct run_process_parallel_opts
 {
+	/**
+	 * tr2_category & tr2_label: sets the trace2 category and label for
+	 * logging. These must either be unset, or both of them must be set.
+	 */
+	const char *tr2_category;
+	const char *tr2_label;
+
 	/**
 	 * processes: see 'processes' in run_processes_parallel() below.
 	 */
-- 
2.38.0.971.ge79ff6d20e7