[igt-dev] [PATCH i-g-t 3/4] tools/intel_gpu_top: Optimise interactive display a bit

[Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>]

From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Padding the percentage bars and table columns with spaces happens quite a
lot so lets do better than putchar at a time. Have a table of visually
empty strings and build the required length out of those chunks.

While at it, also move the percentage bar table into its function scope.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
 tools/intel_gpu_top.c | 38 +++++++++++++++++++++++++++++++++-----
 1 file changed, 33 insertions(+), 5 deletions(-)

diff --git a/tools/intel_gpu_top.c b/tools/intel_gpu_top.c
index c5abd0c92155..472ce3f13ba9 100644
--- a/tools/intel_gpu_top.c
+++ b/tools/intel_gpu_top.c
@@ -926,14 +926,40 @@ static void free_display_clients(struct igt_drm_clients *clients)
 	free(clients);
 }
 
-static const char *bars[] = { " ", "▏", "▎", "▍", "▌", "▋", "▊", "▉", "█" };
-
 static unsigned int n_spaces(const unsigned int n)
 {
-	unsigned int i;
+	static const char *spaces[] = {
+		" ",
+		"  ",
+		"   ",
+		"    ",
+		"     ",
+		"      ",
+		"       ",
+		"        ",
+		"         ",
+		"          ",
+		"           ",
+		"            ",
+		"             ",
+		"              ",
+		"               ",
+		"                ",
+		"                 ",
+		"                  ",
+		"                   ",
+#define MAX_SPACES 19
+	};
+	unsigned int i, r = n;
 
-	for (i = 0; i < n; i++)
-		putchar(' ');
+	while (r) {
+		if (r > MAX_SPACES)
+			i = MAX_SPACES - 1;
+		else
+			i = r - 1;
+		fputs(spaces[i], stdout);
+		r -= i + 1;
+	}
 
 	return n;
 }
@@ -941,6 +967,8 @@ static unsigned int n_spaces(const unsigned int n)
 static void
 print_percentage_bar(double percent, double max, int max_len, bool numeric)
 {
+	static const char *bars[] =
+		{ " ", "▏", "▎", "▍", "▌", "▋", "▊", "▉", "█" };
 	int bar_len, i, len = max_len - 2;
 	const int w = 8;
 
-- 
2.39.2