src/util/hash.h

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