hash_table.h revision af69d88d 
1/*
2 * Copyright © 2009,2012 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 * Authors:
24 *    Eric Anholt <eric@anholt.net>
25 *
26 */
27
28#ifndef _HASH_TABLE_H
29#define _HASH_TABLE_H
30
31#include <stdlib.h>
32#include <inttypes.h>
33#include <stdbool.h>
34#include "c99_compat.h"
35#include "macros.h"
36
37#ifdef __cplusplus
38extern "C" {
39#endif
40
41struct hash_entry {
42   uint32_t hash;
43   const void *key;
44   void *data;
45};
46
47struct hash_table {
48   struct hash_entry *table;
49   bool (*key_equals_function)(const void *a, const void *b);
50   const void *deleted_key;
51   uint32_t size;
52   uint32_t rehash;
53   uint32_t max_entries;
54   uint32_t size_index;
55   uint32_t entries;
56   uint32_t deleted_entries;
57};
58
59struct hash_table *
60_mesa_hash_table_create(void *mem_ctx,
61                        bool (*key_equals_function)(const void *a,
62                                                    const void *b));
63void _mesa_hash_table_destroy(struct hash_table *ht,
64                              void (*delete_function)(struct hash_entry *entry));
65void _mesa_hash_table_set_deleted_key(struct hash_table *ht,
66                                      const void *deleted_key);
67
68struct hash_entry *
69_mesa_hash_table_insert(struct hash_table *ht, uint32_t hash,
70                        const void *key, void *data);
71struct hash_entry *
72_mesa_hash_table_search(struct hash_table *ht, uint32_t hash,
73                        const void *key);
74void _mesa_hash_table_remove(struct hash_table *ht,
75                             struct hash_entry *entry);
76
77struct hash_entry *_mesa_hash_table_next_entry(struct hash_table *ht,
78                                               struct hash_entry *entry);
79struct hash_entry *
80_mesa_hash_table_random_entry(struct hash_table *ht,
81                              bool (*predicate)(struct hash_entry *entry));
82
83uint32_t _mesa_hash_data(const void *data, size_t size);
84uint32_t _mesa_hash_string(const char *key);
85bool _mesa_key_string_equal(const void *a, const void *b);
86bool _mesa_key_pointer_equal(const void *a, const void *b);
87
88static inline uint32_t _mesa_hash_pointer(const void *pointer)
89{
90   return _mesa_hash_data(&pointer, sizeof(pointer));
91}
92
93/**
94 * This foreach function is safe against deletion (which just replaces
95 * an entry's data with the deleted marker), but not against insertion
96 * (which may rehash the table, making entry a dangling pointer).
97 */
98#define hash_table_foreach(ht, entry)                   \
99   for (entry = _mesa_hash_table_next_entry(ht, NULL);  \
100        entry != NULL;                                  \
101        entry = _mesa_hash_table_next_entry(ht, entry))
102
103#ifdef __cplusplus
104} /* extern C */
105#endif
106
107#endif /* _HASH_TABLE_H */
108