path: root/src/libevent/hash.h (plain)
blob: 6169c6ee83741e9647bc29f781679ace78795e15

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
55