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/*
htop - linux/Battery.c
(C) 2004-2014 Hisham H. Muhammad
Released under the GNU GPL, see the COPYING file
in the source distribution for its full text.
Linux battery readings written by Ian P. Hands (iphands@gmail.com, ihands@redhat.com).
*/
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <dirent.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <time.h>
#include "BatteryMeter.h"
#include "StringUtils.h"
#define SYS_POWERSUPPLY_DIR "/sys/class/power_supply"
// ----------------------------------------
// READ FROM /proc
// ----------------------------------------
// This implementation reading from from /proc/acpi is really inefficient,
// but I think this is on the way out so I did not rewrite it.
// The /sys implementation below does things the right way.
static unsigned long int parseBatInfo(const char *fileName, const unsigned short int lineNum, const unsigned short int wordNum) {
const char batteryPath[] = PROCDIR "/acpi/battery/";
DIR* batteryDir = opendir(batteryPath);
if (!batteryDir)
return 0;
#define MAX_BATTERIES 64
char* batteries[MAX_BATTERIES];
unsigned int nBatteries = 0;
memset(batteries, 0, MAX_BATTERIES * sizeof(char*));
struct dirent result;
struct dirent* dirEntry;
while (nBatteries < MAX_BATTERIES) {
int err = readdir_r(batteryDir, &result, &dirEntry);
if (err || !dirEntry)
break;
char* entryName = dirEntry->d_name;
if (strncmp(entryName, "BAT", 3))
continue;
batteries[nBatteries] = strdup(entryName);
nBatteries++;
}
closedir(batteryDir);
unsigned long int total = 0;
for (unsigned int i = 0; i < nBatteries; i++) {
char infoPath[30];
snprintf(infoPath, sizeof infoPath, "%s%s/%s", batteryPath, batteries[i], fileName);
FILE* file = fopen(infoPath, "r");
if (!file) {
break;
}
char line[50] = "";
for (unsigned short int i = 0; i < lineNum; i++) {
char* ok = fgets(line, sizeof line, file);
if (!ok) break;
}
fclose(file);
char *foundNumStr = String_getToken(line, wordNum);
const unsigned long int foundNum = atoi(foundNumStr);
free(foundNumStr);
total += foundNum;
}
for (unsigned int i = 0; i < nBatteries; i++) {
free(batteries[i]);
}
return total;
}
static ACPresence procAcpiCheck() {
ACPresence isOn = AC_ERROR;
const char *power_supplyPath = PROCDIR "/acpi/ac_adapter";
DIR *dir = opendir(power_supplyPath);
if (!dir) {
return AC_ERROR;
}
struct dirent result;
struct dirent* dirEntry;
for (;;) {
int err = readdir_r((DIR *) dir, &result, &dirEntry);
if (err || !dirEntry)
break;
char* entryName = (char *) dirEntry->d_name;
if (entryName[0] != 'A')
continue;
char statePath[50];
snprintf((char *) statePath, sizeof statePath, "%s/%s/state", power_supplyPath, entryName);
FILE* file = fopen(statePath, "r");
if (!file) {
isOn = AC_ERROR;
continue;
}
char line[100];
char* ok = fgets(line, sizeof line, file);
if (!ok) continue;
line[sizeof(line) - 1] = '\0';
fclose(file);
const char *isOnline = String_getToken(line, 2);
if (strcmp(isOnline, "on-line") == 0) {
isOn = AC_PRESENT;
} else {
isOn = AC_ABSENT;
}
free((char *) isOnline);
if (isOn == AC_PRESENT) {
break;
}
}
if (dir)
closedir(dir);
return isOn;
}
static double Battery_getProcBatData() {
const unsigned long int totalFull = parseBatInfo("info", 3, 4);
if (totalFull == 0)
return 0;
const unsigned long int totalRemain = parseBatInfo("state", 5, 3);
if (totalRemain == 0)
return 0;
return totalRemain * 100.0 / (double) totalFull;
}
static void Battery_getProcData(double* level, ACPresence* isOnAC) {
*level = Battery_getProcBatData();
*isOnAC = procAcpiCheck();
}
// ----------------------------------------
// READ FROM /sys
// ----------------------------------------
static inline ssize_t xread(int fd, void *buf, size_t count) {
// Read some bytes. Retry on EINTR and when we don't get as many bytes as we requested.
size_t alreadyRead = 0;
for(;;) {
ssize_t res = read(fd, buf, count);
if (res == -1 && errno == EINTR) continue;
if (res > 0) {
buf = ((char*)buf)+res;
count -= res;
alreadyRead += res;
}
if (res == -1) return -1;
if (count == 0 || res == 0) return alreadyRead;
}
}
/**
* Returns a pointer to the suffix of `str` if its beginning matches `prefix`.
* Returns NULL if the prefix does not match.
* Examples:
* match("hello world", "hello "); -> "world"
* match("hello world", "goodbye "); -> NULL
*/
static inline const char* match(const char* str, const char* prefix) {
for (;;) {
if (*prefix == '\0') {
return str;
}
if (*prefix != *str) {
return NULL;
}
prefix++; str++;
}
}
static void Battery_getSysData(double* level, ACPresence* isOnAC) {
*level = 0;
*isOnAC = AC_ERROR;
DIR *dir = opendir(SYS_POWERSUPPLY_DIR);
if (!dir)
return;
unsigned long int totalFull = 0;
unsigned long int totalRemain = 0;
struct dirent result;
struct dirent* dirEntry;
for (;;) {
int err = readdir_r((DIR *) dir, &result, &dirEntry);
if (err || !dirEntry)
break;
char* entryName = (char *) dirEntry->d_name;
const char filePath[50];
if (entryName[0] == 'B' && entryName[1] == 'A' && entryName[2] == 'T') {
snprintf((char *) filePath, sizeof filePath, SYS_POWERSUPPLY_DIR "/%s/uevent", entryName);
int fd = open(filePath, O_RDONLY);
if (fd == -1) {
closedir(dir);
return;
}
char buffer[1024];
ssize_t buflen = xread(fd, buffer, 1023);
close(fd);
if (buflen < 1) {
closedir(dir);
return;
}
buffer[buflen] = '\0';
char *buf = buffer;
char *line = NULL;
bool full = false;
bool now = false;
while ((line = strsep(&buf, "\n")) != NULL) {
const char* ps = match(line, "POWER_SUPPLY_");
if (!ps) {
continue;
}
const char* energy = match(ps, "ENERGY_");
if (!energy) {
energy = match(ps, "CHARGE_");
}
if (!energy) {
continue;
}
const char* value = (!full) ? match(energy, "FULL=") : NULL;
if (value) {
totalFull += atoi(value);
full = true;
if (now) break;
continue;
}
value = (!now) ? match(energy, "NOW=") : NULL;
if (value) {
totalRemain += atoi(value);
now = true;
if (full) break;
continue;
}
}
} else if (entryName[0] == 'A') {
if (*isOnAC != AC_ERROR) {
continue;
}
snprintf((char *) filePath, sizeof filePath, SYS_POWERSUPPLY_DIR "/%s/online", entryName);
int fd = open(filePath, O_RDONLY);
if (fd == -1) {
closedir(dir);
return;
}
char buffer[2] = "";
for(;;) {
ssize_t res = read(fd, buffer, 1);
if (res == -1 && errno == EINTR) continue;
break;
}
close(fd);
if (buffer[0] == '0') {
*isOnAC = AC_ABSENT;
} else if (buffer[0] == '1') {
*isOnAC = AC_PRESENT;
}
}
}
closedir(dir);
*level = totalFull > 0 ? ((double) totalRemain * 100) / (double) totalFull : 0;
}
static enum { BAT_PROC, BAT_SYS, BAT_ERR } Battery_method = BAT_PROC;
static time_t Battery_cacheTime = 0;
static double Battery_cacheLevel = 0;
static ACPresence Battery_cacheIsOnAC = 0;
void Battery_getData(double* level, ACPresence* isOnAC) {
time_t now = time(NULL);
// update battery reading is slow. Update it each 10 seconds only.
if (now < Battery_cacheTime + 10) {
*level = Battery_cacheLevel;
*isOnAC = Battery_cacheIsOnAC;
return;
}
if (Battery_method == BAT_PROC) {
Battery_getProcData(level, isOnAC);
if (*level == 0) {
Battery_method = BAT_SYS;
}
}
if (Battery_method == BAT_SYS) {
Battery_getSysData(level, isOnAC);
if (*level == 0) {
Battery_method = BAT_ERR;
}
}
if (Battery_method == BAT_ERR) {
*level = -1;
*isOnAC = AC_ERROR;
}
Battery_cacheLevel = *level;
Battery_cacheIsOnAC = *isOnAC;
Battery_cacheTime = now;
}