From f4e4fcd8c12450e843dec5ceaefca87dabf19e25 Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <djwong@us.ibm.com>
Date: Thu, 17 Apr 2008 01:30:37 +0000
Subject: [PATCH] Subject: [PATCH 3/3 v3]: sensors: Automatically scale
 energy/power units

Automatically scale energy and power values when printing them in cooked
mode.  Fixed all the warnings and warts that were brought up by Jean in
the previous thread.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>



git-svn-id: http://lm-sensors.org/svn/lm-sensors/branches/lm-sensors-3.0.0@5185 7894878c-1315-0410-8ee3-d5d059ff63e0
---
 CHANGES              |  2 +-
 prog/sensors/chips.c | 60 +++++++++++++++++++++++++++++++++++++-------
 2 files changed, 52 insertions(+), 10 deletions(-)

diff --git a/CHANGES b/CHANGES
index 23bfab9e..23641efe 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2,7 +2,7 @@ lm-sensors CHANGES file
 -----------------------
 
 SVN-HEAD
-  sensors: Print energy and power sensors
+  sensors: Print energy and power sensors with automatically scaled units
   libsensors: Use __func__ instead of __FUNCTION__
               Parse the configuration file in C locale
               Late compute statements override early ones
diff --git a/prog/sensors/chips.c b/prog/sensors/chips.c
index 52ab5e04..47a2d056 100644
--- a/prog/sensors/chips.c
+++ b/prog/sensors/chips.c
@@ -23,6 +23,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <math.h>
 
 #include "main.h"
 #include "chips.h"
@@ -401,13 +402,44 @@ static void print_chip_fan(const sensors_chip_name *name,
 	printf("\n");
 }
 
+struct scale_table {
+	double upper_bound;
+	const char *unit;
+};
+
+static void scale_value(double *value, const char **prefixstr)
+{
+	double abs_value = fabs(*value);
+	double divisor = 1e-9;
+	static struct scale_table prefix_scales[] = {
+		{1e-6, "n"},
+		{1e-3, "u"},
+		{1,    "m"},
+		{1e3,   ""},
+		{1e6,  "k"},
+		{1e9,  "M"},
+		{0,    "G"}, /* no upper bound */
+	};
+	struct scale_table *scale = prefix_scales;
+
+	while (scale->upper_bound && abs_value > scale->upper_bound) {
+		divisor = scale->upper_bound;
+		scale++;
+	}
+
+	*value /= divisor;
+	*prefixstr = scale->unit;
+}
+
 static void print_chip_power(const sensors_chip_name *name,
 			     const sensors_feature *feature,
 			     int label_size)
 {
+	double val;
 	int need_space = 0;
 	const sensors_subfeature *sf, *sfmin, *sfmax, *sfint;
 	char *label;
+	const char *unit;
 
 	if (!(label = sensors_get_label(name, feature))) {
 		fprintf(stderr, "ERROR: Can't get label of feature %s!\n",
@@ -419,9 +451,11 @@ static void print_chip_power(const sensors_chip_name *name,
 
 	sf = sensors_get_subfeature(name, feature,
 				    SENSORS_SUBFEATURE_POWER_AVERAGE);
-	if (sf)
-		printf("%6.2f W", get_value(name, sf));
-	else
+	if (sf) {
+		val = get_value(name, sf);
+		scale_value(&val, &unit);
+		printf("%6.2f %sW", val, unit);
+	} else
 		printf("     N/A");
 
 	sfmin = sensors_get_subfeature(name, feature,
@@ -434,13 +468,17 @@ static void print_chip_power(const sensors_chip_name *name,
 		printf("  (");
 
 		if (sfmin) {
-			printf("min = %6.2f W", get_value(name, sfmin));
+			val = get_value(name, sfmin);
+			scale_value(&val, &unit);
+			printf("min = %6.2f %sW", val, unit);
 			need_space = 1;
 		}
 
 		if (sfmax) {
-			printf("%smax = %6.2f W", (need_space ? ", " : ""),
-			       get_value(name, sfmax));
+			val = get_value(name, sfmax);
+			scale_value(&val, &unit);
+			printf("%smax = %6.2f %sW", (need_space ? ", " : ""),
+			       val, unit);
 			need_space = 1;
 		}
 
@@ -459,8 +497,10 @@ static void print_chip_energy(const sensors_chip_name *name,
 			      const sensors_feature *feature,
 			      int label_size)
 {
+	double val;
 	const sensors_subfeature *sf;
 	char *label;
+	const char *unit;
 
 	if (!(label = sensors_get_label(name, feature))) {
 		fprintf(stderr, "ERROR: Can't get label of feature %s!\n",
@@ -472,9 +512,11 @@ static void print_chip_energy(const sensors_chip_name *name,
 
 	sf = sensors_get_subfeature(name, feature,
 				    SENSORS_SUBFEATURE_ENERGY_INPUT);
-	if (sf)
-		printf("%6.2f J", get_value(name, sf));
-	else
+	if (sf) {
+		val = get_value(name, sf);
+		scale_value(&val, &unit);
+		printf("%6.2f %sJ", val, unit);
+	} else
 		printf("     N/A");
 
 	printf("\n");