hashmap.h

   1 #ifndef HASHMAP_H
   2 #define HASHMAP_H
   3
   4 /*
   5  * Generic implementation of hash-based key-value mappings.
   6  * See Documentation/technical/api-hashmap.txt.
   7  */
   8
   9 /* FNV-1 functions */
  10
  11 extern unsigned int strhash(const char *buf);
  12 extern unsigned int strihash(const char *buf);
  13 extern unsigned int memhash(const void *buf, size_t len);
  14 extern unsigned int memihash(const void *buf, size_t len);
  15
  16 /* data structures */
  17
  18 struct hashmap_entry {
  19         struct hashmap_entry *next;
  20         unsigned int hash;
  21 };
  22
  23 typedef int (*hashmap_cmp_fn)(const void *entry, const void *entry_or_key,
  24                 const void *keydata);
  25
  26 struct hashmap {
  27         struct hashmap_entry **table;
  28         hashmap_cmp_fn cmpfn;
  29         unsigned int size, tablesize, grow_at, shrink_at;
  30 };
  31
  32 struct hashmap_iter {
  33         struct hashmap *map;
  34         struct hashmap_entry *next;
  35         unsigned int tablepos;
  36 };
  37
  38 /* hashmap functions */
  39
  40 extern void hashmap_init(struct hashmap *map, hashmap_cmp_fn equals_function,
  41                 size_t initial_size);
  42 extern void hashmap_free(struct hashmap *map, int free_entries);
  43
  44 /* hashmap_entry functions */
  45
  46 static inline void hashmap_entry_init(void *entry, unsigned int hash)
  47 {
  48         struct hashmap_entry *e = entry;
  49         e->hash = hash;
  50         e->next = NULL;
  51 }
  52 extern void *hashmap_get(const struct hashmap *map, const void *key,
  53                 const void *keydata);
  54 extern void *hashmap_get_next(const struct hashmap *map, const void *entry);
  55 extern void hashmap_add(struct hashmap *map, void *entry);
  56 extern void *hashmap_put(struct hashmap *map, void *entry);
  57 extern void *hashmap_remove(struct hashmap *map, const void *key,
  58                 const void *keydata);
  59
  60 /* hashmap_iter functions */
  61
  62 extern void hashmap_iter_init(struct hashmap *map, struct hashmap_iter *iter);
  63 extern void *hashmap_iter_next(struct hashmap_iter *iter);
  64 static inline void *hashmap_iter_first(struct hashmap *map,
  65                 struct hashmap_iter *iter)
  66 {
  67         hashmap_iter_init(map, iter);
  68         return hashmap_iter_next(iter);
  69 }
  70
  71 #endif