components/swap.c

   1 /* See LICENSE file for copyright and license details. */
   2 #include <errno.h>
   3 #include <stdint.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7
   8 #include "../util.h"
   9
  10 #if defined(__linux__)
  11         static int
  12         get_swap_info(long *s_total, long *s_free, long *s_cached)
  13         {
  14                 FILE *fp;
  15                 struct {
  16                         const char *name;
  17                         const size_t len;
  18                         long *var;
  19                 } ent[] = {
  20                         { "SwapTotal",  sizeof("SwapTotal") - 1,  s_total  },
  21                         { "SwapFree",   sizeof("SwapFree") - 1,   s_free   },
  22                         { "SwapCached", sizeof("SwapCached") - 1, s_cached },
  23                 };
  24                 size_t line_len = 0, i, left;
  25                 char *line = NULL;
  26
  27                 /* get number of fields we want to extract */
  28                 for (i = 0, left = 0; i < LEN(ent); i++) {
  29                         if (ent[i].var) {
  30                                 left++;
  31                         }
  32                 }
  33
  34                 if (!(fp = fopen("/proc/meminfo", "r"))) {
  35                         warn("fopen '/proc/meminfo':");
  36                         return 1;
  37                 }
  38
  39                 /* read file line by line and extract field information */
  40                 while (left > 0 && getline(&line, &line_len, fp) >= 0) {
  41                         for (i = 0; i < LEN(ent); i++) {
  42                                 if (ent[i].var &&
  43                                     !strncmp(line, ent[i].name, ent[i].len)) {
  44                                         sscanf(line + ent[i].len + 1, "%ld kB\n",
  45                                                ent[i].var);
  46                                         left--;
  47                                         break;
  48                                 }
  49                         }
  50                 }
  51                 free(line);
  52                 if (ferror(fp)) {
  53                         warn("getline '/proc/meminfo':");
  54                         return 1;
  55                 }
  56
  57                 fclose(fp);
  58                 return 0;
  59         }
  60
  61         const char *
  62         swap_free(void)
  63         {
  64                 long free;
  65
  66                 if (get_swap_info(NULL, &free, NULL)) {
  67                         return NULL;
  68                 }
  69
  70                 return fmt_human(free * 1024, 1024);
  71         }
  72
  73         const char *
  74         swap_perc(void)
  75         {
  76                 long total, free, cached;
  77
  78                 if (get_swap_info(&total, &free, &cached) || total == 0) {
  79                         return NULL;
  80                 }
  81
  82                 return bprintf("%d", 100 * (total - free - cached) / total);
  83         }
  84
  85         const char *
  86         swap_total(void)
  87         {
  88                 long total;
  89
  90                 if (get_swap_info(&total, NULL, NULL)) {
  91                         return NULL;
  92                 }
  93
  94                 return fmt_human(total * 1024, 1024);
  95         }
  96
  97         const char *
  98         swap_used(void)
  99         {
 100                 long total, free, cached;
 101
 102                 if (get_swap_info(&total, &free, &cached)) {
 103                         return NULL;
 104                 }
 105
 106                 return fmt_human((total - free - cached) * 1024, 1024);
 107         }
 108 #elif defined(__OpenBSD__)
 109         #include <stdlib.h>
 110         #include <sys/param.h> /* dbtob */
 111         #include <sys/swap.h>
 112         #include <sys/types.h>
 113         #include <unistd.h>
 114
 115         static int
 116         getstats(int *total, int *used)
 117         {
 118                 struct swapent *sep, *fsep;
 119                 int rnswap, nswap, i;
 120
 121                 if ((nswap = swapctl(SWAP_NSWAP, 0, 0)) < 1) {
 122                         warn("swaptctl 'SWAP_NSWAP':");
 123                         return 1;
 124                 }
 125                 if (!(fsep = sep = calloc(nswap, sizeof(*sep)))) {
 126                         warn("calloc 'nswap':");
 127                         return 1;
 128                 }
 129                 if ((rnswap = swapctl(SWAP_STATS, (void *)sep, nswap)) < 0) {
 130                         warn("swapctl 'SWAP_STATA':");
 131                         return 1;
 132                 }
 133                 if (nswap != rnswap) {
 134                         warn("getstats: SWAP_STATS != SWAP_NSWAP");
 135                         return 1;
 136                 }
 137
 138                 *total = 0;
 139                 *used = 0;
 140
 141                 for (i = 0; i < rnswap; i++) {
 142                         *total += sep->se_nblks >> 1;
 143                         *used += sep->se_inuse >> 1;
 144                 }
 145
 146                 free(fsep);
 147
 148                 return 0;
 149         }
 150
 151         const char *
 152         swap_free(void)
 153         {
 154                 int total, used;
 155
 156                 if (getstats(&total, &used)) {
 157                         return NULL;
 158                 }
 159
 160                 return fmt_human((total - used) * 1024, 1024);
 161         }
 162
 163         const char *
 164         swap_perc(void)
 165         {
 166                 int total, used;
 167
 168                 if (getstats(&total, &used)) {
 169                         return NULL;
 170                 }
 171
 172                 if (total == 0) {
 173                         return NULL;
 174                 }
 175
 176                 return bprintf("%d", 100 * used / total);
 177         }
 178
 179         const char *
 180         swap_total(void)
 181         {
 182                 int total, used;
 183
 184                 if (getstats(&total, &used)) {
 185                         return NULL;
 186                 }
 187
 188                 return fmt_human(total * 1024, 1024);
 189         }
 190
 191         const char *
 192         swap_used(void)
 193         {
 194                 int total, used;
 195
 196                 if (getstats(&total, &used)) {
 197                         return NULL;
 198                 }
 199
 200                 return fmt_human(used * 1024, 1024);
 201         }
 202 #endif