perf stat: Split print_metric_headers() function

The print_metric_headers() shows metric headers a little bit for each
mode.  Split it out to make the code clearer.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20221114230227.1255976-11-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/stat-display.c

@@ -924,6 +924,37 @@ static const char *aggr_header_csv[] = {
 	[AGGR_GLOBAL] 	=	""
 };
 
+static void print_metric_headers_std(struct perf_stat_config *config,
+				     const char *prefix, bool no_indent)
+{
+	if (prefix)
+		fprintf(config->output, "%s", prefix);
+	if (!no_indent) {
+		fprintf(config->output, "%*s",
+			aggr_header_lens[config->aggr_mode], "");
+	}
+}
+
+static void print_metric_headers_csv(struct perf_stat_config *config,
+				     const char *prefix,
+				     bool no_indent __maybe_unused)
+{
+	if (prefix)
+		fprintf(config->output, "%s", prefix);
+	if (config->interval)
+		fputs("time,", config->output);
+	if (!config->iostat_run)
+		fputs(aggr_header_csv[config->aggr_mode], config->output);
+}
+
+static void print_metric_headers_json(struct perf_stat_config *config,
+				      const char *prefix __maybe_unused,
+				      bool no_indent __maybe_unused)
+{
+	if (config->interval)
+		fputs("{\"unit\" : \"sec\"}", config->output);
+}
+
 static void print_metric_headers(struct perf_stat_config *config,
 				 struct evlist *evlist,
 				 const char *prefix, bool no_indent)
@@ -939,22 +970,13 @@ static void print_metric_headers(struct perf_stat_config *config,
 		.force_header = true,
 	};
 
-	if (prefix && !config->json_output)
-		fprintf(config->output, "%s", prefix);
+	if (config->json_output)
+		print_metric_headers_json(config, prefix, no_indent);
+	else if (config->csv_output)
+		print_metric_headers_csv(config, prefix, no_indent);
+	else
+		print_metric_headers_std(config, prefix, no_indent);
 
-	if (!config->csv_output && !config->json_output && !no_indent)
-		fprintf(config->output, "%*s",
-			aggr_header_lens[config->aggr_mode], "");
-	if (config->csv_output) {
-		if (config->interval)
-			fputs("time,", config->output);
-		if (!config->iostat_run)
-			fputs(aggr_header_csv[config->aggr_mode], config->output);
-	}
-	if (config->json_output) {
-		if (config->interval)
-			fputs("{\"unit\" : \"sec\"}", config->output);
-	}
 	if (config->iostat_run)
 		iostat_print_header_prefix(config);