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1 /*
2  * Copyright © 2008 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  */
24 
25 #ifndef STRING_TO_UINT_MAP_H
26 #define STRING_TO_UINT_MAP_H
27 
28 #include <string.h>
29 #include <limits.h>
30 #include "util/hash_table.h"
31 
32 struct string_to_uint_map;
33 
34 #ifdef __cplusplus
35 extern "C" {
36 #endif
37 
38 struct string_to_uint_map *
39 string_to_uint_map_ctor();
40 
41 void
42 string_to_uint_map_dtor(struct string_to_uint_map *);
43 
44 
45 #ifdef __cplusplus
46 }
47 
48 struct string_map_iterate_wrapper_closure {
49    void (*callback)(const char *key, unsigned value, void *closure);
50    void *closure;
51 };
52 
53 /**
54  * Map from a string (name) to an unsigned integer value
55  *
56  * \note
57  * Because of the way this class interacts with the \c hash_table
58  * implementation, values of \c UINT_MAX cannot be stored in the map.
59  */
60 struct string_to_uint_map {
61 public:
string_to_uint_mapstring_to_uint_map62    string_to_uint_map()
63    {
64       this->ht = _mesa_hash_table_create(NULL, _mesa_key_hash_string,
65                                          _mesa_key_string_equal);
66    }
67 
~string_to_uint_mapstring_to_uint_map68    ~string_to_uint_map()
69    {
70       hash_table_call_foreach(this->ht, delete_key, NULL);
71       _mesa_hash_table_destroy(this->ht, NULL);
72    }
73 
74    /**
75     * Remove all mappings from this map.
76     */
clearstring_to_uint_map77    void clear()
78    {
79       hash_table_call_foreach(this->ht, delete_key, NULL);
80       _mesa_hash_table_clear(this->ht, NULL);
81    }
82 
83    /**
84     * Runs a passed callback for the hash
85     */
iteratestring_to_uint_map86    void iterate(void (*func)(const char *, unsigned, void *), void *closure)
87    {
88       struct string_map_iterate_wrapper_closure *wrapper;
89 
90       wrapper = (struct string_map_iterate_wrapper_closure *)
91          malloc(sizeof(struct string_map_iterate_wrapper_closure));
92       if (wrapper == NULL)
93          return;
94 
95       wrapper->callback = func;
96       wrapper->closure = closure;
97 
98       hash_table_call_foreach(this->ht, subtract_one_wrapper, wrapper);
99       free(wrapper);
100    }
101 
102    /**
103     * Get the value associated with a particular key
104     *
105     * \return
106     * If \c key is found in the map, \c true is returned.  Otherwise \c false
107     * is returned.
108     *
109     * \note
110     * If \c key is not found in the table, \c value is not modified.
111     */
getstring_to_uint_map112    bool get(unsigned &value, const char *key)
113    {
114       hash_entry *entry = _mesa_hash_table_search(this->ht,
115                                                   (const void *) key);
116 
117       if (!entry)
118          return false;
119 
120       const intptr_t v = (intptr_t) entry->data;
121       value = (unsigned)(v - 1);
122       return true;
123    }
124 
putstring_to_uint_map125    void put(unsigned value, const char *key)
126    {
127       /* The low-level hash table structure returns NULL if key is not in the
128        * hash table.  However, users of this map might want to store zero as a
129        * valid value in the table.  Bias the value by +1 so that a
130        * user-specified zero is stored as 1.  This enables ::get to tell the
131        * difference between a user-specified zero (returned as 1 by
132        * _mesa_hash_table_search) and the key not in the table (returned as 0 by
133        * _mesa_hash_table_search).
134        *
135        * The net effect is that we can't store UINT_MAX in the table.  This is
136        * because UINT_MAX+1 = 0.
137        */
138       assert(value != UINT_MAX);
139       char *dup_key = strdup(key);
140 
141       struct hash_entry *entry = _mesa_hash_table_search(this->ht, dup_key);
142       if (entry) {
143          entry->data = (void *) (intptr_t) (value + 1);
144       } else {
145          _mesa_hash_table_insert(this->ht, dup_key,
146                                  (void *) (intptr_t) (value + 1));
147       }
148 
149       if (entry)
150          free(dup_key);
151    }
152 
153 private:
delete_keystring_to_uint_map154    static void delete_key(const void *key, void *data, void *closure)
155    {
156       (void) data;
157       (void) closure;
158 
159       free((char *)key);
160    }
161 
subtract_one_wrapperstring_to_uint_map162    static void subtract_one_wrapper(const void *key, void *data, void *closure)
163    {
164       struct string_map_iterate_wrapper_closure *wrapper =
165          (struct string_map_iterate_wrapper_closure *) closure;
166       unsigned value = (intptr_t) data;
167 
168       value -= 1;
169 
170       wrapper->callback((const char *) key, value, wrapper->closure);
171    }
172 
173    struct hash_table *ht;
174 };
175 
176 #endif /* __cplusplus */
177 #endif /* STRING_TO_UINT_MAP_H */
178