slstatus/components/swap.c
Laslo Hunhold a18439af11 Refactor swap.c to use getline() instead of buf-filling
This drops a lot of code and even though we are using a common function,
the specification of only the needed things keeps it very efficient and
even more efficient in memory and time than the previous solution.
2018-05-28 22:21:34 +02:00

202 lines
3.4 KiB
C

/* See LICENSE file for copyright and license details. */
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "../util.h"
#if defined(__linux__)
static int
get_swap_info(long *s_total, long *s_free, long *s_cached)
{
FILE *fp;
struct {
const char *name;
const size_t len;
long *var;
} ent[] = {
{ "SwapTotal", sizeof("SwapTotal") - 1, s_total },
{ "SwapFree", sizeof("SwapFree") - 1, s_free },
{ "SwapCached", sizeof("SwapCached") - 1, s_cached },
};
size_t line_len = 0, i, left;
char *line = NULL;
/* get number of fields we want to extract */
for (i = 0, left = 0; i < LEN(ent); i++) {
if (ent[i].var) {
left++;
}
}
if (!(fp = fopen("/proc/meminfo", "r"))) {
warn("fopen '/proc/meminfo':");
return 1;
}
/* read file line by line and extract field information */
while (left > 0 && getline(&line, &line_len, fp) >= 0) {
for (i = 0; i < LEN(ent); i++) {
if (ent[i].var &&
!strncmp(line, ent[i].name, ent[i].len)) {
sscanf(line + ent[i].len + 1, "%ld kB\n",
ent[i].var);
left--;
break;
}
}
}
free(line);
if (ferror(fp)) {
warn("getline '/proc/meminfo':");
return 1;
}
fclose(fp);
return 0;
}
const char *
swap_free(void)
{
long free;
if (get_swap_info(NULL, &free, NULL)) {
return NULL;
}
return fmt_human(free * 1024, 1024);
}
const char *
swap_perc(void)
{
long total, free, cached;
if (get_swap_info(&total, &free, &cached) || total == 0) {
return NULL;
}
return bprintf("%d", 100 * (total - free - cached) / total);
}
const char *
swap_total(void)
{
long total;
if (get_swap_info(&total, NULL, NULL)) {
return NULL;
}
return fmt_human(total * 1024, 1024);
}
const char *
swap_used(void)
{
long total, free, cached;
if (get_swap_info(&total, &free, &cached)) {
return NULL;
}
return fmt_human((total - free - cached) * 1024, 1024);
}
#elif defined(__OpenBSD__)
#include <stdlib.h>
#include <sys/param.h> /* dbtob */
#include <sys/swap.h>
#include <sys/types.h>
#include <unistd.h>
static int
getstats(int *total, int *used)
{
struct swapent *sep, *fsep;
int rnswap, nswap, i;
if ((nswap = swapctl(SWAP_NSWAP, 0, 0)) < 1) {
warn("swaptctl 'SWAP_NSWAP':");
return 1;
}
if (!(fsep = sep = calloc(nswap, sizeof(*sep)))) {
warn("calloc 'nswap':");
return 1;
}
if ((rnswap = swapctl(SWAP_STATS, (void *)sep, nswap)) < 0) {
warn("swapctl 'SWAP_STATA':");
return 1;
}
if (nswap != rnswap) {
warn("getstats: SWAP_STATS != SWAP_NSWAP");
return 1;
}
*total = 0;
*used = 0;
for (i = 0; i < rnswap; i++) {
*total += sep->se_nblks >> 1;
*used += sep->se_inuse >> 1;
}
free(fsep);
return 0;
}
const char *
swap_free(void)
{
int total, used;
if (getstats(&total, &used)) {
return NULL;
}
return fmt_human((total - used) * 1024, 1024);
}
const char *
swap_perc(void)
{
int total, used;
if (getstats(&total, &used)) {
return NULL;
}
if (total == 0) {
return NULL;
}
return bprintf("%d", 100 * used / total);
}
const char *
swap_total(void)
{
int total, used;
if (getstats(&total, &used)) {
return NULL;
}
return fmt_human(total * 1024, 1024);
}
const char *
swap_used(void)
{
int total, used;
if (getstats(&total, &used)) {
return NULL;
}
return fmt_human(used * 1024, 1024);
}
#endif