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ram: Check for theoretical division by zero
[slstatus.git] / components / swap.c
diff --git a/components/swap.c b/components/swap.c
index 08a97de..b3b519e 100644 (file)
--- a/components/swap.c
+++ b/components/swap.c
@@ -1,152 +1,200 @@
 /* See LICENSE file for copyright and license details. */
 /* See LICENSE file for copyright and license details. */
-#if defined(__linux__)
-       #include <errno.h>
-       #include <stdio.h>
-       #include <string.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
 
-       #include "../util.h"
+#include "../util.h"
 
 
-       const char *
-       swap_free(void)
+#if defined(__linux__)
+       static int
+       get_swap_info(long *s_total, long *s_free, long *s_cached)
        {
        {
-               long total, free;
                FILE *fp;
                FILE *fp;
-               size_t bytes_read;
-               char *match;
+               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++;
+                       }
+               }
 
 
-               fp = fopen("/proc/meminfo", "r");
-               if (fp == NULL) {
-                       fprintf(stderr, "fopen '/proc/meminfo': %s\n",
-                               strerror(errno));
-                       return NULL;
+               if (!(fp = fopen("/proc/meminfo", "r"))) {
+                       warn("fopen '/proc/meminfo':");
+                       return 1;
                }
 
                }
 
-               if ((bytes_read = fread(buf, sizeof(char), sizeof(buf) - 1,
-                                       fp)) == 0) {
-                       fprintf(stderr, "fread '/proc/meminfo': %s\n",
-                               strerror(errno));
-                       fclose(fp);
-                       return NULL;
+               /* 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);
                fclose(fp);
+               return 0;
+       }
 
 
-               if ((match = strstr(buf, "SwapTotal")) == NULL)
-                       return NULL;
-               sscanf(match, "SwapTotal: %ld kB\n", &total);
+       const char *
+       swap_free(void)
+       {
+               long free;
 
 
-               if ((match = strstr(buf, "SwapFree")) == NULL)
+               if (get_swap_info(NULL, &free, NULL)) {
                        return NULL;
                        return NULL;
-               sscanf(match, "SwapFree: %ld kB\n", &free);
+               }
 
 
-               return bprintf("%f", (float)free / 1024 / 1024);
+               return fmt_human(free * 1024, 1024);
        }
 
        const char *
        swap_perc(void)
        {
                long total, free, cached;
        }
 
        const char *
        swap_perc(void)
        {
                long total, free, cached;
-               FILE *fp;
-               size_t bytes_read;
-               char *match;
 
 
-               fp = fopen("/proc/meminfo", "r");
-               if (fp == NULL) {
-                       fprintf(stderr, "fopen '/proc/meminfo': %s\n",
-                               strerror(errno));
+               if (get_swap_info(&total, &free, &cached) || total == 0) {
                        return NULL;
                }
 
                        return NULL;
                }
 
-               if ((bytes_read = fread(buf, sizeof(char), sizeof(buf) - 1,
-                                       fp)) == 0) {
-                       fprintf(stderr, "fread '/proc/meminfo': %s\n",
-                               strerror(errno));
-                       fclose(fp);
+               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 NULL;
                }
-               fclose(fp);
 
 
-               if ((match = strstr(buf, "SwapTotal")) == NULL)
-                       return NULL;
-               sscanf(match, "SwapTotal: %ld kB\n", &total);
+               return fmt_human(total * 1024, 1024);
+       }
 
 
-               if ((match = strstr(buf, "SwapCached")) == NULL)
-                       return NULL;
-               sscanf(match, "SwapCached: %ld kB\n", &cached);
+       const char *
+       swap_used(void)
+       {
+               long total, free, cached;
 
 
-               if ((match = strstr(buf, "SwapFree")) == NULL)
+               if (get_swap_info(&total, &free, &cached)) {
                        return NULL;
                        return NULL;
-               sscanf(match, "SwapFree: %ld kB\n", &free);
+               }
 
 
-               return bprintf("%d", 100 * (total - free - cached) / total);
+               return fmt_human((total - free - cached) * 1024, 1024);
        }
        }
+#elif defined(__OpenBSD__)
+       #include <stdlib.h>
+       #include <sys/swap.h>
+       #include <sys/types.h>
+       #include <unistd.h>
 
 
-       const char *
-       swap_total(void)
+       static int
+       getstats(int *total, int *used)
        {
        {
-               long total;
-               FILE *fp;
-               size_t bytes_read;
-               char *match;
+               struct swapent *sep, *fsep;
+               int rnswap, nswap, i;
 
 
-               fp = fopen("/proc/meminfo", "r");
-               if (fp == NULL) {
-                       fprintf(stderr, "fopen '/proc/meminfo': %s\n",
-                               strerror(errno));
-                       return NULL;
+               if ((nswap = swapctl(SWAP_NSWAP, 0, 0)) < 1) {
+                       warn("swaptctl 'SWAP_NSWAP':");
+                       return 1;
                }
                }
-               if ((bytes_read = fread(buf, sizeof(char), sizeof(buf) - 1,
-                                       fp)) == 0) {
-                       fprintf(stderr, "fread '/proc/meminfo': %s\n",
-                               strerror(errno));
-                       fclose(fp);
-                       return NULL;
+               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;
                }
                }
-               fclose(fp);
 
 
-               if ((match = strstr(buf, "SwapTotal")) == NULL)
-                       return NULL;
-               sscanf(match, "SwapTotal: %ld kB\n", &total);
+               *total = 0;
+               *used = 0;
+
+               for (i = 0; i < rnswap; i++) {
+                       *total += sep->se_nblks >> 1;
+                       *used += sep->se_inuse >> 1;
+               }
+
+               free(fsep);
 
 
-               return bprintf("%f", (float)total / 1024 / 1024);
+               return 0;
        }
 
        const char *
        }
 
        const char *
-       swap_used(void)
+       swap_free(void)
        {
        {
-               long total, free, cached;
-               FILE *fp;
-               size_t bytes_read;
-               char *match;
+               int total, used;
 
 
-               fp = fopen("/proc/meminfo", "r");
-               if (fp == NULL) {
-                       fprintf(stderr, "fopen '/proc/meminfo': %s\n",
-                               strerror(errno));
+               if (getstats(&total, &used)) {
                        return NULL;
                }
                        return NULL;
                }
-               if ((bytes_read = fread(buf, sizeof(char), sizeof(buf) - 1,
-                                       fp)) == 0) {
-                       fprintf(stderr, "fread '/proc/meminfo': %s\n",
-                               strerror(errno));
-                       fclose(fp);
+
+               return fmt_human((total - used) * 1024, 1024);
+       }
+
+       const char *
+       swap_perc(void)
+       {
+               int total, used;
+
+               if (getstats(&total, &used)) {
                        return NULL;
                }
                        return NULL;
                }
-               fclose(fp);
 
 
-               if ((match = strstr(buf, "SwapTotal")) == NULL)
+               if (total == 0) {
                        return NULL;
                        return NULL;
-               sscanf(match, "SwapTotal: %ld kB\n", &total);
+               }
+
+               return bprintf("%d", 100 * used / total);
+       }
+
+       const char *
+       swap_total(void)
+       {
+               int total, used;
 
 
-               if ((match = strstr(buf, "SwapCached")) == NULL)
+               if (getstats(&total, &used)) {
                        return NULL;
                        return NULL;
-               sscanf(match, "SwapCached: %ld kB\n", &cached);
+               }
+
+               return fmt_human(total * 1024, 1024);
+       }
 
 
-               if ((match = strstr(buf, "SwapFree")) == NULL)
+       const char *
+       swap_used(void)
+       {
+               int total, used;
+
+               if (getstats(&total, &used)) {
                        return NULL;
                        return NULL;
-               sscanf(match, "SwapFree: %ld kB\n", &free);
+               }
 
 
-               return bprintf("%f", (float)(total - free - cached) / 1024 / 1024);
+               return fmt_human(used * 1024, 1024);
        }
        }
-#elif defined(__OpenBSD__)
-       /* unimplemented */
 #endif
 #endif