linux/Battery.c - htop - Rivoreo Source Code Repositories

 /*
 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;
 }
	/*
	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;
	}