perf diff: Color the Ratio column

In

  $ perf diff -c ratio

color the Ratio column using value_color_snprintf(), a new function that
operates exactly like percent_color_snprintf().

At first glance, it looks like percent_color_snprintf() can be turned
into a non-variadic function simplifying things; however, 53805ec (perf
tools: Remove cast of non-variadic function to variadic, 2013-10-31)
explains why it needs to be a variadic function.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1388388861-7931-4-git-send-email-artagnon@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-diff.c

@@ -795,6 +795,17 @@ static int __hpp__color_compare(struct perf_hpp_fmt *fmt,
 		scnprintf(pfmt, 20, "%%%+d.2f%%%%", dfmt->header_width - 1);
 		return percent_color_snprintf(hpp->buf, hpp->size,
 					pfmt, diff);
+	case COMPUTE_RATIO:
+		if (he->dummy)
+			goto dummy_print;
+		if (pair->diff.computed)
+			diff = pair->diff.period_ratio;
+		else
+			diff = compute_ratio(he, pair);
+
+		scnprintf(pfmt, 20, "%%%d.6f", dfmt->header_width);
+		return value_color_snprintf(hpp->buf, hpp->size,
+					pfmt, diff);
 	default:
 		BUG_ON(1);
 	}
@@ -809,6 +820,12 @@ static int hpp__color_delta(struct perf_hpp_fmt *fmt,
 	return __hpp__color_compare(fmt, hpp, he, COMPUTE_DELTA);
 }
 
+static int hpp__color_ratio(struct perf_hpp_fmt *fmt,
+			struct perf_hpp *hpp, struct hist_entry *he)
+{
+	return __hpp__color_compare(fmt, hpp, he, COMPUTE_RATIO);
+}
+
 static void
 hpp__entry_unpair(struct hist_entry *he, int idx, char *buf, size_t size)
 {
@@ -987,6 +1004,9 @@ static void data__hpp_register(struct data__file *d, int idx)
 	case PERF_HPP_DIFF__DELTA:
 		fmt->color = hpp__color_delta;
 		break;
+	case PERF_HPP_DIFF__RATIO:
+		fmt->color = hpp__color_ratio;
+		break;
 	default:
 		break;
 	}

tools/perf/util/color.c

@@ -319,15 +319,19 @@ int percent_color_fprintf(FILE *fp, const char *fmt, double percent)
 	return r;
 }
 
+int value_color_snprintf(char *bf, size_t size, const char *fmt, double value)
+{
+	const char *color = get_percent_color(value);
+	return color_snprintf(bf, size, color, fmt, value);
+}
+
 int percent_color_snprintf(char *bf, size_t size, const char *fmt, ...)
 {
 	va_list args;
 	double percent;
-	const char *color;
 
 	va_start(args, fmt);
 	percent = va_arg(args, double);
 	va_end(args);
-	color = get_percent_color(percent);
-	return color_snprintf(bf, size, color, fmt, percent);
+	return value_color_snprintf(bf, size, fmt, percent);
 }

tools/perf/util/color.h

@@ -39,6 +39,7 @@ int color_fprintf(FILE *fp, const char *color, const char *fmt, ...);
 int color_snprintf(char *bf, size_t size, const char *color, const char *fmt, ...);
 int color_fprintf_ln(FILE *fp, const char *color, const char *fmt, ...);
 int color_fwrite_lines(FILE *fp, const char *color, size_t count, const char *buf);
+int value_color_snprintf(char *bf, size_t size, const char *fmt, double value);
 int percent_color_snprintf(char *bf, size_t size, const char *fmt, ...);
 int percent_color_fprintf(FILE *fp, const char *fmt, double percent);
 const char *get_percent_color(double percent);