components/swap.c

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