1/* Hash routine.
2   Copyright (C) 1998 Kunihiro Ishiguro
3
4This file is part of GNU Zebra.
5
6GNU Zebra is free software; you can redistribute it and/or modify
7it under the terms of the GNU General Public License as published
8by the Free Software Foundation; either version 2, or (at your
9option) any later version.
10
11GNU Zebra is distributed in the hope that it will be useful, but
12WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14General Public License for more details.
15
16You should have received a copy of the GNU General Public License
17along with GNU Zebra; see the file COPYING.  If not, write to the
18Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19Boston, MA 02111-1307, USA.  */
20
21#ifndef _ZEBRA_HASH_H
22#define _ZEBRA_HASH_H
23
24/* Default hash table size.  */
25#define HASH_INITIAL_SIZE     256	/* initial number of backets. */
26#define HASH_THRESHOLD	      10	/* expand when backet. */
27
28struct hash_backet
29{
30  /* Linked list.  */
31  struct hash_backet *next;
32
33  /* Hash key. */
34  unsigned int key;
35
36  /* Data.  */
37  void *data;
38};
39
40struct hash
41{
42  /* Hash backet. */
43  struct hash_backet **index;
44
45  /* Hash table size. Must be power of 2 */
46  unsigned int size;
47
48  /* If expansion failed. */
49  int no_expand;
50
51  /* Key make function. */
52  unsigned int (*hash_key) (void *);
53
54  /* Data compare function. */
55  int (*hash_cmp) (const void *, const void *);
56
57  /* Backet alloc. */
58  unsigned long count;
59};
60
61extern struct hash *hash_create (unsigned int (*) (void *),
62				 int (*) (const void *, const void *));
63extern struct hash *hash_create_size (unsigned int, unsigned int (*) (void *),
64                                             int (*) (const void *, const void *));
65
66extern void *hash_get (struct hash *, void *, void * (*) (void *));
67extern void *hash_alloc_intern (void *);
68extern void *hash_lookup (struct hash *, void *);
69extern void *hash_release (struct hash *, void *);
70
71extern void hash_iterate (struct hash *,
72		   void (*) (struct hash_backet *, void *), void *);
73
74extern void hash_clean (struct hash *, void (*) (void *));
75extern void hash_free (struct hash *);
76
77extern unsigned int string_hash_make (const char *);
78
79#endif /* _ZEBRA_HASH_H */
80