hash_table.h revision 01e04c3f 
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   uint32_t (*key_hash_function)(const void *key);
50   bool (*key_equals_function)(const void *a, const void *b);
51   const void *deleted_key;
52   uint32_t size;
53   uint32_t rehash;
54   uint32_t max_entries;
55   uint32_t size_index;
56   uint32_t entries;
57   uint32_t deleted_entries;
58};
59
60struct hash_table *
61_mesa_hash_table_create(void *mem_ctx,
62                        uint32_t (*key_hash_function)(const void *key),
63                        bool (*key_equals_function)(const void *a,
64                                                    const void *b));
65struct hash_table *
66_mesa_hash_table_clone(struct hash_table *src, void *dst_mem_ctx);
67void _mesa_hash_table_destroy(struct hash_table *ht,
68                              void (*delete_function)(struct hash_entry *entry));
69void _mesa_hash_table_clear(struct hash_table *ht,
70                            void (*delete_function)(struct hash_entry *entry));
71void _mesa_hash_table_set_deleted_key(struct hash_table *ht,
72                                      const void *deleted_key);
73
74static inline uint32_t _mesa_hash_table_num_entries(struct hash_table *ht)
75{
76   return ht->entries;
77}
78
79struct hash_entry *
80_mesa_hash_table_insert(struct hash_table *ht, const void *key, void *data);
81struct hash_entry *
82_mesa_hash_table_insert_pre_hashed(struct hash_table *ht, uint32_t hash,
83                                   const void *key, void *data);
84struct hash_entry *
85_mesa_hash_table_search(struct hash_table *ht, const void *key);
86struct hash_entry *
87_mesa_hash_table_search_pre_hashed(struct hash_table *ht, uint32_t hash,
88                                  const void *key);
89void _mesa_hash_table_remove(struct hash_table *ht,
90                             struct hash_entry *entry);
91void _mesa_hash_table_remove_key(struct hash_table *ht,
92                                 const void *key);
93
94struct hash_entry *_mesa_hash_table_next_entry(struct hash_table *ht,
95                                               struct hash_entry *entry);
96struct hash_entry *
97_mesa_hash_table_random_entry(struct hash_table *ht,
98                              bool (*predicate)(struct hash_entry *entry));
99
100uint32_t _mesa_hash_data(const void *data, size_t size);
101uint32_t _mesa_hash_string(const void *key);
102bool _mesa_key_string_equal(const void *a, const void *b);
103bool _mesa_key_pointer_equal(const void *a, const void *b);
104
105static inline uint32_t _mesa_key_hash_string(const void *key)
106{
107   return _mesa_hash_string((const char *)key);
108}
109
110static inline uint32_t _mesa_hash_pointer(const void *pointer)
111{
112   uintptr_t num = (uintptr_t) pointer;
113   return (uint32_t) ((num >> 2) ^ (num >> 6) ^ (num >> 10) ^ (num >> 14));
114}
115
116enum {
117   _mesa_fnv32_1a_offset_bias = 2166136261u,
118};
119
120static inline uint32_t
121_mesa_fnv32_1a_accumulate_block(uint32_t hash, const void *data, size_t size)
122{
123   const uint8_t *bytes = (const uint8_t *)data;
124
125   while (size-- != 0) {
126      hash ^= *bytes;
127      hash = hash * 0x01000193;
128      bytes++;
129   }
130
131   return hash;
132}
133
134#define _mesa_fnv32_1a_accumulate(hash, expr) \
135   _mesa_fnv32_1a_accumulate_block(hash, &(expr), sizeof(expr))
136
137/**
138 * This foreach function is safe against deletion (which just replaces
139 * an entry's data with the deleted marker), but not against insertion
140 * (which may rehash the table, making entry a dangling pointer).
141 */
142#define hash_table_foreach(ht, entry)                                      \
143   for (struct hash_entry *entry = _mesa_hash_table_next_entry(ht, NULL);  \
144        entry != NULL;                                                     \
145        entry = _mesa_hash_table_next_entry(ht, entry))
146
147static inline void
148hash_table_call_foreach(struct hash_table *ht,
149                        void (*callback)(const void *key,
150                                         void *data,
151                                         void *closure),
152                        void *closure)
153{
154   hash_table_foreach(ht, entry)
155      callback(entry->key, entry->data, closure);
156}
157
158/**
159 * Hash table wrapper which supports 64-bit keys.
160 */
161struct hash_table_u64 {
162   struct hash_table *table;
163   void *deleted_key_data;
164};
165
166struct hash_table_u64 *
167_mesa_hash_table_u64_create(void *mem_ctx);
168
169void
170_mesa_hash_table_u64_destroy(struct hash_table_u64 *ht,
171                             void (*delete_function)(struct hash_entry *entry));
172
173void
174_mesa_hash_table_u64_insert(struct hash_table_u64 *ht, uint64_t key,
175                            void *data);
176
177void *
178_mesa_hash_table_u64_search(struct hash_table_u64 *ht, uint64_t key);
179
180void
181_mesa_hash_table_u64_remove(struct hash_table_u64 *ht, uint64_t key);
182
183#ifdef __cplusplus
184} /* extern C */
185#endif
186
187#endif /* _HASH_TABLE_H */
188