From: Hugo Villeneuve <hugo@hugovil.com>
Date: Fri, 6 Mar 2015 19:34:26 +0000 (-0500)
Subject: Add support to evaluate battery capacity from energy
X-Git-Url: http://gitweb.hugovil.com/?a=commitdiff_plain;h=10dede9eb616edf48c8ba132d695a714df1ece5a;p=dockapps%2Fdockbatmon.git

Add support to evaluate battery capacity from energy
---

diff --git a/src/batmon.c b/src/batmon.c
index d4aa03a..d1e502c 100644
--- a/src/batmon.c
+++ b/src/batmon.c
@@ -64,69 +64,98 @@ static const char ac[] = "AC0";
 static const char ac_acpi_dir_base[] = "/sys/class/power_supply";
 static const char battery_acpi_dir_base[] = "/sys/class/power_supply";
 
-static void read_ac_status(void)
+static int
+read_int_from_file(const char *path)
 {
-	FILE *ac_file;
-	char ac_file_path[256], ac_file_line[40];
-
- 	sprintf(ac_file_path, "%s/%s/online", ac_acpi_dir_base,
-		ac);
+	FILE *fp;
+	int value;
 
-	ac_file = fopen(ac_file_path, "r");
+	if (access(path, F_OK ) < 0) {
+		/* File not found, abort. */
+		fprintf(stderr, "Missing file.\n");
+		exit(EXIT_FAILURE);
+	}
 
-	if (ac_file == NULL) {
-		perror(ac_file_path);
-		fprintf(stderr,
-			"Unable to find power supply AC online status.\n");
+	fp = fopen(path, "r");
+	if (fp == NULL) {
+		/* File could not be read, abort. */
+		perror(path);
+		fprintf(stderr, "Unable to read file.\n");
 		exit(EXIT_FAILURE);
 	} else {
-		while (!feof(ac_file)) {
-			memset(ac_file_line, 0, 40);
-			fgets(ac_file_line, 40, ac_file);
-
-			sscanf(ac_file_line, "%d", &ac_online);
+		char buf[40];
 
-			break;
-		}
+		memset(buf, 0, sizeof(buf));
+		fgets(buf, sizeof(buf), fp);
+		sscanf(buf, "%d", &value);
 
 #ifdef DEBUG_ACPI
-		printf("ac online = %d\n", ac_online);
+		printf("value = %d\n", value);
 #endif /* DEBUG_ACPI */
 	}
 
-	fclose(ac_file);
+	fclose(fp);
+
+	return value;
 }
 
-static void read_battery_status(void)
+static void read_ac_status(void)
 {
-	FILE *batt_file;
-	char batt_file_path[256], batt_file_line[40];
+	char path[256];
 
- 	sprintf(batt_file_path, "%s/%s/capacity", battery_acpi_dir_base,
-		battery);
+	sprintf(path, "%s/%s/online", ac_acpi_dir_base, ac);
 
-	batt_file = fopen(batt_file_path, "r");
-
-	if (batt_file == NULL) {
-		perror(batt_file_path);
+	if (access(path, F_OK ) < 0) {
+		perror(path);
 		fprintf(stderr,
-			"Unable to determine battery capacity.\n");
+			"Unable to find power supply AC online status.\n");
 		exit(EXIT_FAILURE);
-	} else {
-		while (!feof(batt_file)) {
-			memset(batt_file_line, 0, 40);
-			fgets(batt_file_line, 40, batt_file);
+	}
 
-			sscanf(batt_file_line, "%d", &capacity);
-			break;
-		}
+	ac_online = read_int_from_file(path);
 
 #ifdef DEBUG_ACPI
-		printf("capacity = %d%%\n", capacity);
+	printf("ac online = %d\n", ac_online);
 #endif /* DEBUG_ACPI */
-	}
+}
+
+static void
+compute_battery_capacity_from_energy(void)
+{
+	char path[256];
+	int64_t full, now;
 
-	fclose(batt_file);
+	sprintf(path, "%s/%s/energy_full", battery_acpi_dir_base, battery);
+#ifdef DEBUG_ACPI
+	printf("Energy full: ");
+#endif /* DEBUG_ACPI */
+	full = read_int_from_file(path);
+
+	sprintf(path, "%s/%s/energy_now", battery_acpi_dir_base, battery);
+#ifdef DEBUG_ACPI
+	printf("Energy now:  ");
+#endif /* DEBUG_ACPI */
+	now = read_int_from_file(path);
+
+	capacity = (now * 100) / full;
+
+#ifdef DEBUG_ACPI
+	printf("capacity = %d%%\n", capacity);
+#endif /* DEBUG_ACPI */
+}
+
+static void read_battery_capacity(void)
+{
+	char path[256];
+
+	sprintf(path, "%s/%s/capacity", battery_acpi_dir_base, battery);
+
+	if (access(path, F_OK ) < 0) {
+		/* Capacity file doesn't exist, try reading energy... */
+		compute_battery_capacity_from_energy();
+	} else {
+		capacity = read_int_from_file(path);
+	}
 }
 
 static void
@@ -233,7 +262,7 @@ draw_background(cairo_t *cr)
 	int height;
 
 	read_ac_status();
-	read_battery_status();
+	read_battery_capacity();
 
 	cairo_save(cr);