release/src/router/rp-l2tp/libevent/hash.h

   1 /***********************************************************************
   2 *
   3 * hash.h
   4 *
   5 * Hash table utilities
   6 *
   7 * Copyright (C) 2002 Roaring Penguin Software Inc.
   8 *
   9 * LIC: GPL
  10 *
  11 ***********************************************************************/
  12
  13 #ifndef HASH_H
  14 #define HASH_H
  15
  16 #include <stdlib.h>
  17 /* Fixed-size hash tables for now */
  18 #define HASHTAB_SIZE 67
  19
  20 /* A hash bucket */
  21 typedef struct hash_bucket_t {
  22     struct hash_bucket_t *next;
  23     struct hash_bucket_t *prev;
  24     unsigned int hashval;
  25 } hash_bucket;
  26
  27 /* A hash table */
  28 typedef struct hash_table_t {
  29     hash_bucket *buckets[HASHTAB_SIZE];
  30     size_t hash_offset;
  31     unsigned int (*compute_hash)(void *data);
  32     int (*compare)(void *item1, void *item2);
  33     size_t num_entries;
  34 } hash_table;
  35
  36 /* Functions */
  37 void hash_init(hash_table *tab,
  38                size_t hash_offset,
  39                unsigned int (*compute)(void *data),
  40                int (*compare)(void *item1, void *item2));
  41 void hash_insert(hash_table *tab, void *item);
  42 void hash_remove(hash_table *tab, void *item);
  43 void *hash_find(hash_table *tab, void *item);
  44 void *hash_find_next(hash_table *tab, void *item);
  45 size_t hash_num_entries(hash_table *tab);
  46
  47 /* Iteration functions */
  48 void *hash_start(hash_table *tab, void **cursor);
  49 void *hash_next(hash_table *tab, void **cursor);
  50
  51 /* Utility function: hashpjw for strings */
  52 unsigned int hash_pjw(char const *str);
  53
  54 #endif