1 /**************************************************************************
2  *
3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
4  * All Rights Reserved.
5  *
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:
13  *
14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
17  *
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.
25  *
26  **************************************************************************/
27 
28 /**
29  * @file
30  * Hash table implementation.
31  *
32  * This file provides a hash implementation that is capable of dealing
33  * with collisions. It stores colliding entries in linked list. All
34  * functions operating on the hash return an iterator. The iterator
35  * itself points to the collision list. If there wasn't any collision
36  * the list will have just one entry, otherwise client code should
37  * iterate over the entries to find the exact entry among ones that
38  * had the same key (e.g. memcmp could be used on the data to check
39  * that)
40  *
41  * @author Zack Rusin <zack@tungstengraphics.com>
42  */
43 
44 #ifndef CSO_HASH_H
45 #define CSO_HASH_H
46 
47 #include "pipe/p_compiler.h"
48 
49 #ifdef	__cplusplus
50 extern "C" {
51 #endif
52 
53 
54 struct cso_hash;
55 struct cso_node;
56 
57 
58 struct cso_hash_iter {
59    struct cso_hash *hash;
60    struct cso_node  *node;
61 };
62 
63 
64 struct cso_hash *cso_hash_create(void);
65 void             cso_hash_delete(struct cso_hash *hash);
66 
67 
68 int              cso_hash_size(struct cso_hash *hash);
69 
70 
71 /**
72  * Adds a data with the given key to the hash. If entry with the given
73  * key is already in the hash, this current entry is instered before it
74  * in the collision list.
75  * Function returns iterator pointing to the inserted item in the hash.
76  */
77 struct cso_hash_iter cso_hash_insert(struct cso_hash *hash, unsigned key,
78                                      void *data);
79 /**
80  * Removes the item pointed to by the current iterator from the hash.
81  * Note that the data itself is not erased and if it was a malloc'ed pointer
82  * it will have to be freed after calling this function by the callee.
83  * Function returns iterator pointing to the item after the removed one in
84  * the hash.
85  */
86 struct cso_hash_iter cso_hash_erase(struct cso_hash *hash, struct cso_hash_iter iter);
87 
88 void  *cso_hash_take(struct cso_hash *hash, unsigned key);
89 
90 
91 
92 struct cso_hash_iter cso_hash_first_node(struct cso_hash *hash);
93 
94 /**
95  * Return an iterator pointing to the first entry in the collision list.
96  */
97 struct cso_hash_iter cso_hash_find(struct cso_hash *hash, unsigned key);
98 
99 /**
100  * Returns true if a value with the given key exists in the hash
101  */
102 boolean   cso_hash_contains(struct cso_hash *hash, unsigned key);
103 
104 
105 int       cso_hash_iter_is_null(struct cso_hash_iter iter);
106 unsigned  cso_hash_iter_key(struct cso_hash_iter iter);
107 void     *cso_hash_iter_data(struct cso_hash_iter iter);
108 
109 
110 struct cso_hash_iter cso_hash_iter_next(struct cso_hash_iter iter);
111 struct cso_hash_iter cso_hash_iter_prev(struct cso_hash_iter iter);
112 
113 
114 /**
115  * Convenience routine to iterate over the collision list while doing a memory
116  * comparison to see which entry in the list is a direct copy of our template
117  * and returns that entry.
118  */
119 void *cso_hash_find_data_from_template( struct cso_hash *hash,
120 				        unsigned hash_key,
121 				        void *templ,
122 				        int size );
123 
124 
125 #ifdef	__cplusplus
126 }
127 #endif
128 
129 #endif
130