src/util/hash_table.h

   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
  38 extern "C" {
  39 #endif
  40
  41 struct hash_entry {
  42    uint32_t hash;
  43    const void *key;
  44    void *data;
  45 };
  46
  47 struct 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
  60 struct 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));
  65 void _mesa_hash_table_destroy(struct hash_table *ht,
  66                               void (*delete_function)(struct hash_entry *entry));
  67 void _mesa_hash_table_clear(struct hash_table *ht,
  68                             void (*delete_function)(struct hash_entry *entry));
  69 void _mesa_hash_table_set_deleted_key(struct hash_table *ht,
  70                                       const void *deleted_key);
  71
  72 static inline uint32_t _mesa_hash_table_num_entries(struct hash_table *ht)
  73 {
  74    return ht->entries;
  75 }
  76
  77 struct hash_entry *
  78 _mesa_hash_table_insert(struct hash_table *ht, const void *key, void *data);
  79 struct hash_entry *
  80 _mesa_hash_table_insert_pre_hashed(struct hash_table *ht, uint32_t hash,
  81                                    const void *key, void *data);
  82 struct hash_entry *
  83 _mesa_hash_table_search(struct hash_table *ht, const void *key);
  84 struct hash_entry *
  85 _mesa_hash_table_search_pre_hashed(struct hash_table *ht, uint32_t hash,
  86                                   const void *key);
  87 void _mesa_hash_table_remove(struct hash_table *ht,
  88                              struct hash_entry *entry);
  89
  90 struct hash_entry *_mesa_hash_table_next_entry(struct hash_table *ht,
  91                                                struct hash_entry *entry);
  92 struct hash_entry *
  93 _mesa_hash_table_random_entry(struct hash_table *ht,
  94                               bool (*predicate)(struct hash_entry *entry));
  95
  96 uint32_t _mesa_hash_data(const void *data, size_t size);
  97 uint32_t _mesa_hash_string(const char *key);
  98 bool _mesa_key_string_equal(const void *a, const void *b);
  99 bool _mesa_key_pointer_equal(const void *a, const void *b);
 100
 101 static inline uint32_t _mesa_key_hash_string(const void *key)
 102 {
 103    return _mesa_hash_string((const char *)key);
 104 }
 105
 106 static inline uint32_t _mesa_hash_pointer(const void *pointer)
 107 {
 108    uintptr_t num = (uintptr_t) pointer;
 109    return (uint32_t) ((num >> 2) ^ (num >> 6) ^ (num >> 10) ^ (num >> 14));
 110 }
 111
 112 enum {
 113    _mesa_fnv32_1a_offset_bias = 2166136261u,
 114 };
 115
 116 static inline uint32_t
 117 _mesa_fnv32_1a_accumulate_block(uint32_t hash, const void *data, size_t size)
 118 {
 119    const uint8_t *bytes = (const uint8_t *)data;
 120
 121    while (size-- != 0) {
 122       hash ^= *bytes;
 123       hash = hash * 0x01000193;
 124       bytes++;
 125    }
 126
 127    return hash;
 128 }
 129
 130 #define _mesa_fnv32_1a_accumulate(hash, expr) \
 131    _mesa_fnv32_1a_accumulate_block(hash, &(expr), sizeof(expr))
 132
 133 /**
 134  * This foreach function is safe against deletion (which just replaces
 135  * an entry's data with the deleted marker), but not against insertion
 136  * (which may rehash the table, making entry a dangling pointer).
 137  */
 138 #define hash_table_foreach(ht, entry)                   \
 139    for (entry = _mesa_hash_table_next_entry(ht, NULL);  \
 140         entry != NULL;                                  \
 141         entry = _mesa_hash_table_next_entry(ht, entry))
 142
 143 static inline void
 144 hash_table_call_foreach(struct hash_table *ht,
 145                         void (*callback)(const void *key,
 146                                          void *data,
 147                                          void *closure),
 148                         void *closure)
 149 {
 150    struct hash_entry *entry;
 151
 152    hash_table_foreach(ht, entry)
 153       callback(entry->key, entry->data, closure);
 154 }
 155
 156 /**
 157  * Hash table wrapper which supports 64-bit keys.
 158  */
 159 struct hash_table_u64 {
 160    struct hash_table *table;
 161    void *deleted_key_data;
 162 };
 163
 164 struct hash_table_u64 *
 165 _mesa_hash_table_u64_create(void *mem_ctx);
 166
 167 void
 168 _mesa_hash_table_u64_destroy(struct hash_table_u64 *ht,
 169                              void (*delete_function)(struct hash_entry *entry));
 170
 171 void
 172 _mesa_hash_table_u64_insert(struct hash_table_u64 *ht, uint64_t key,
 173                             void *data);
 174
 175 void *
 176 _mesa_hash_table_u64_search(struct hash_table_u64 *ht, uint64_t key);
 177
 178 void
 179 _mesa_hash_table_u64_remove(struct hash_table_u64 *ht, uint64_t key);
 180
 181 #ifdef __cplusplus
 182 } /* extern C */
 183 #endif
 184
 185 #endif /* _HASH_TABLE_H */