1 /*
2 * Copyright 2016 Jakub Klama <jceel@FreeBSD.org>
3 * All rights reserved
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted providing that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
18 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
22 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
23 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24 * POSSIBILITY OF SUCH DAMAGE.
25 *
26 */
27
28 #ifndef LIB9P_HASHTABLE_H
29 #define LIB9P_HASHTABLE_H
30
31 #include <pthread.h>
32 #include <sys/queue.h>
33
34 struct ht {
35 struct ht_entry * ht_entries;
36 ssize_t ht_nentries;
37 pthread_rwlock_t ht_rwlock;
38 };
39
40 struct ht_entry {
41 TAILQ_HEAD(, ht_item) hte_items;
42 };
43
44 struct ht_item {
45 uint32_t hti_hash;
46 void * hti_data;
47 TAILQ_ENTRY(ht_item) hti_link;
48 };
49
50 struct ht_iter {
51 struct ht * htit_parent;
52 struct ht_item * htit_curr;
53 struct ht_item * htit_next;
54 ssize_t htit_slot;
55 };
56
57 #ifdef __clang__
58 #pragma clang diagnostic push
59 #pragma clang diagnostic ignored "-Wthread-safety-analysis"
60 #endif
61
62 /*
63 * Obtain read-lock on hash table.
64 */
65 static inline int
ht_rdlock(struct ht * h)66 ht_rdlock(struct ht *h)
67 {
68
69 return (pthread_rwlock_rdlock(&h->ht_rwlock));
70 }
71
72 /*
73 * Obtain write-lock on hash table.
74 */
75 static inline int
ht_wrlock(struct ht * h)76 ht_wrlock(struct ht *h)
77 {
78
79 return (pthread_rwlock_wrlock(&h->ht_rwlock));
80 }
81
82 /*
83 * Release lock on hash table.
84 */
85 static inline int
ht_unlock(struct ht * h)86 ht_unlock(struct ht *h)
87 {
88
89 return (pthread_rwlock_unlock(&h->ht_rwlock));
90 }
91
92 #ifdef __clang__
93 #pragma clang diagnostic pop
94 #endif
95
96 void ht_init(struct ht *h, ssize_t size);
97 void ht_destroy(struct ht *h);
98 void *ht_find(struct ht *h, uint32_t hash);
99 void *ht_find_locked(struct ht *h, uint32_t hash);
100 int ht_add(struct ht *h, uint32_t hash, void *value);
101 int ht_remove(struct ht *h, uint32_t hash);
102 int ht_remove_locked(struct ht *h, uint32_t hash);
103 int ht_remove_at_iter(struct ht_iter *iter);
104 void ht_iter(struct ht *h, struct ht_iter *iter);
105 void *ht_next(struct ht_iter *iter);
106
107 #endif /* LIB9P_HASHTABLE_H */
108