src/util/hash.h

   1 #ifndef EL__UTIL_HASH_H
   2 #define EL__UTIL_HASH_H
   3
   4 #include "util/lists.h"
   5
   6 /* This should be hopefully always 32bit at least. I'm not sure what will
   7  * happen when this will be of other length, but it should still work ok.
   8  * --pasky */
   9 typedef unsigned long hash_value_T;
  10 typedef hash_value_T (* hash_func_T)(unsigned char *key, unsigned int keylen, hash_value_T magic);
  11
  12 struct hash_item {
  13         LIST_HEAD(struct hash_item);
  14
  15         unsigned char *key;
  16         unsigned int keylen;
  17         void *value;
  18 };
  19
  20 struct hash {
  21         unsigned int width; /* Number of bits - hash array must be 2^width long. */
  22         hash_func_T func;
  23         struct list_head hash[1]; /* Must be at end ! */
  24 };
  25
  26 #define hash_size(n) (1 << (n))
  27
  28 struct hash *init_hash(unsigned int width, hash_func_T func);
  29 void free_hash(struct hash *hash);
  30
  31 struct hash_item *add_hash_item(struct hash *hash, unsigned char *key, unsigned int keylen, void *value);
  32 struct hash_item *get_hash_item(struct hash *hash, unsigned char *key, unsigned int keylen);
  33 void del_hash_item(struct hash *hash, struct hash_item *item);
  34 hash_value_T strhash(unsigned char *k, unsigned int length, hash_value_T initval);
  35
  36 #define foreach_hash_item(item, hash_table, iterator) \
  37         for (iterator = 0; iterator < hash_size((hash_table).width); iterator++) \
  38                 foreach (item, (hash_table).hash[iterator])
  39
  40 #endif