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
32struct string_to_uint_map;
33
34#ifdef __cplusplus
35extern "C" {
36#endif
37
38struct string_to_uint_map *
39string_to_uint_map_ctor();
40
41void
42string_to_uint_map_dtor(struct string_to_uint_map *);
43
44
45#ifdef __cplusplus
46}
47
48struct 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 */
60struct string_to_uint_map {
61public:
62   string_to_uint_map()
63   {
64      this->ht = _mesa_hash_table_create(NULL, _mesa_hash_string,
65                                         _mesa_key_string_equal);
66   }
67
68   ~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    */
77   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    */
86   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    */
112   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
125   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
153private:
154   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
162   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