spark.c

 1// SPDX-License-Identifier: GPL-2.0
 2#include "spark.h"
 3#include <limits.h>
 4#include <linux/kernel.h>
 5
 6#define SPARK_SHIFT 8
 7
 8/* Print spark lines on outf for numval values in val. */
 9int print_spark(char *bf, int size, unsigned long *val, int numval)
10{
11	static const char *ticks[NUM_SPARKS] = {
12		"▁",  "▂", "▃", "▄", "▅", "▆", "▇", "█"
13	};
14	int i, printed = 0;
15	unsigned long min = ULONG_MAX, max = 0, f;
16
17	for (i = 0; i < numval; i++) {
18		if (val[i] < min)
19			min = val[i];
20		if (val[i] > max)
21			max = val[i];
22	}
23	f = ((max - min) << SPARK_SHIFT) / (NUM_SPARKS - 1);
24	if (f < 1)
25		f = 1;
26	for (i = 0; i < numval; i++) {
27		printed += scnprintf(bf + printed, size - printed, "%s",
28				     ticks[((val[i] - min) << SPARK_SHIFT) / f]);
29	}
30
31	return printed;
32}