src/mesa/main/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 #include <inttypes.h>
  29 #include <stdbool.h>
  30
  31 #ifndef _HASH_TABLE_H
  32 #define _HASH_TABLE_H
  33
  34 #ifdef __cplusplus
  35 extern "C" {
  36 #endif
  37
  38 struct hash_entry {
  39    uint32_t hash;
  40    const void *key;
  41    void *data;
  42 };
  43
  44 struct hash_table {
  45    void *mem_ctx;
  46    struct hash_entry *table;
  47    bool (*key_equals_function)(const void *a, const void *b);
  48    const void *deleted_key;
  49    uint32_t size;
  50    uint32_t rehash;
  51    uint32_t max_entries;
  52    uint32_t size_index;
  53    uint32_t entries;
  54    uint32_t deleted_entries;
  55 };
  56
  57 struct hash_table *
  58 _mesa_hash_table_create(void *mem_ctx,
  59                         bool (*key_equals_function)(const void *a,
  60                                                     const void *b));
  61 void _mesa_hash_table_destroy(struct hash_table *ht,
  62                               void (*delete_function)(struct hash_entry *entry));
  63 void _mesa_hash_table_set_deleted_key(struct hash_table *ht,
  64                                       const void *deleted_key);
  65
  66 struct hash_entry *
  67 _mesa_hash_table_insert(struct hash_table *ht, uint32_t hash,
  68                         const void *key, void *data);
  69 struct hash_entry *
  70 _mesa_hash_table_search(struct hash_table *ht, uint32_t hash,
  71                         const void *key);
  72 void _mesa_hash_table_remove(struct hash_table *ht,
  73                              struct hash_entry *entry);
  74
  75 struct hash_entry *_mesa_hash_table_next_entry(struct hash_table *ht,
  76                                                struct hash_entry *entry);
  77 struct hash_entry *
  78 _mesa_hash_table_random_entry(struct hash_table *ht,
  79                               bool (*predicate)(struct hash_entry *entry));
  80
  81 uint32_t _mesa_hash_data(const void *data, size_t size);
  82 uint32_t _mesa_hash_string(const char *key);
  83 bool _mesa_key_string_equal(const void *a, const void *b);
  84 bool _mesa_key_pointer_equal(const void *a, const void *b);
  85
  86 static inline uint32_t _mesa_hash_pointer(const void *pointer)
  87 {
  88    return _mesa_hash_data(&pointer, sizeof(pointer));
  89 }
  90
  91 /**
  92  * This foreach function is safe against deletion (which just replaces
  93  * an entry's data with the deleted marker), but not against insertion
  94  * (which may rehash the table, making entry a dangling pointer).
  95  */
  96 #define hash_table_foreach(ht, entry)                   \
  97    for (entry = _mesa_hash_table_next_entry(ht, NULL);  \
  98         entry != NULL;                                  \
  99         entry = _mesa_hash_table_next_entry(ht, entry))
 100
 101 #ifdef __cplusplus
 102 } /* extern C */
 103 #endif
 104
 105 #endif /* _HASH_TABLE_H */