1 /**************************************************************************
3 * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 **************************************************************************/
30 * General purpose hash table implementation.
32 * Just uses the cso_hash for now, but it might be better switch to a linear
33 * probing hash table implementation at some point -- as it is said they have
34 * better lookup and cache performance and it appears to be possible to write
35 * a lock-free implementation of such hash tables .
37 * @author José Fonseca <jrfonseca@tungstengraphics.com>
41 #include "pipe/p_compiler.h"
42 #include "pipe/p_debug.h"
43 #include "pipe/p_util.h"
45 #include "cso_cache/cso_hash.h"
46 #include "u_hash_table.h"
54 unsigned (*hash
)(void *key
);
56 /** Compare two keys */
57 int (*compare
)(void *key1
, void *key2
);
59 /* TODO: key, value destructors? */
63 struct hash_table_item
71 hash_table_create(unsigned (*hash
)(void *key
),
72 int (*compare
)(void *key1
, void *key2
))
74 struct hash_table
*ht
;
76 ht
= MALLOC_STRUCT(hash_table
);
80 ht
->cso
= cso_hash_create();
87 ht
->compare
= compare
;
93 static struct hash_table_item
*
94 hash_table_find_item(struct hash_table
*ht
,
98 struct cso_hash_iter iter
;
99 struct hash_table_item
*item
;
101 iter
= cso_hash_find(ht
->cso
, key_hash
);
102 while (!cso_hash_iter_is_null(iter
)) {
103 item
= (struct hash_table_item
*)cso_hash_iter_data(iter
);
104 if (!ht
->compare(item
->key
, key
))
106 iter
= cso_hash_iter_next(iter
);
114 hash_table_set(struct hash_table
*ht
,
119 struct hash_table_item
*item
;
123 key_hash
= ht
->hash(key
);
125 item
= hash_table_find_item(ht
, key
, key_hash
);
127 /* TODO: key/value destruction? */
132 item
= MALLOC_STRUCT(hash_table_item
);
134 return PIPE_ERROR_OUT_OF_MEMORY
;
139 cso_hash_insert(ht
->cso
, key_hash
, item
);
140 /* FIXME: there is no OOM propagation in cso_hash */
143 return PIPE_ERROR_OUT_OF_MEMORY
;
151 hash_table_get(struct hash_table
*ht
,
155 struct hash_table_item
*item
;
159 key_hash
= ht
->hash(key
);
161 item
= hash_table_find_item(ht
, key
, key_hash
);
170 hash_table_remove(struct hash_table
*ht
,
174 struct hash_table_item
*item
;
178 key_hash
= ht
->hash(key
);
180 item
= hash_table_find_item(ht
, key
, key_hash
);
184 /* FIXME: cso_hash_take takes the first element of the collision list
185 * indiscriminately, so we can not take the item down. */
191 hash_table_destroy(struct hash_table
*ht
)
195 cso_hash_delete(ht
->cso
);