tab.c

   1 /* A Dictionary */
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include "mkfn.h"
   5
   6 struct tab {
   7         char **keys;
   8         void **vals;
   9         int n;
  10         int *next;
  11         int head[256];
  12 };
  13
  14 struct tab *tab_alloc(int sz)
  15 {
  16         struct tab *tab = malloc(sizeof(*tab));
  17         int i;
  18         memset(tab, 0, sizeof(*tab));
  19         tab->keys = malloc(sz * sizeof(tab->keys[0]));
  20         tab->vals = malloc(sz * sizeof(tab->vals[0]));
  21         tab->next = malloc(sz * sizeof(tab->next[0]));
  22         for (i = 0; i < 256; i++)
  23                 tab->head[i] = -1;
  24         return tab;
  25 }
  26
  27 void tab_free(struct tab *tab)
  28 {
  29         free(tab->keys);
  30         free(tab->vals);
  31         free(tab->next);
  32         free(tab);
  33 }
  34
  35 void tab_put(struct tab *tab, char *k, void *v)
  36 {
  37         tab->keys[tab->n] = k;
  38         tab->vals[tab->n] = v;
  39         tab->next[tab->n] = tab->head[(unsigned char) k[0]];
  40         tab->head[(unsigned char) k[0]] = tab->n;
  41         tab->n++;
  42 }
  43
  44 void *tab_get(struct tab *tab, char *k)
  45 {
  46         int i = tab->head[(unsigned char) k[0]];
  47         while (i >= 0) {
  48                 if (k[1] == tab->keys[i][1] && !strcmp(k, tab->keys[i]))
  49                         return tab->vals[i];
  50                 i = tab->next[i];
  51         }
  52         return NULL;
  53 }