1 /**************************************************************************
2  *
3  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
4  * All Rights Reserved.
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6  * Permission is hereby granted, free of charge, to any person obtaining a
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8  * "Software"), to deal in the Software without restriction, including
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11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
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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
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27 
28 /**
29  * @file
30  * General purpose hash table implementation.
31  *
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 .
36  *
37  * @author José Fonseca <jrfonseca@tungstengraphics.com>
38  */
39 
40 
41 #include "pipe/p_compiler.h"
42 #include "util/u_debug.h"
43 
44 #include "cso_cache/cso_hash.h"
45 
46 #include "util/u_memory.h"
47 #include "util/u_hash_table.h"
48 
49 
50 struct util_hash_table
51 {
52    struct cso_hash *cso;
53 
54    /** Hash function */
55    unsigned (*hash)(void *key);
56 
57    /** Compare two keys */
58    int (*compare)(void *key1, void *key2);
59 
60    /* TODO: key, value destructors? */
61 };
62 
63 
64 struct util_hash_table_item
65 {
66    void *key;
67    void *value;
68 };
69 
70 
71 static INLINE struct util_hash_table_item *
util_hash_table_item(struct cso_hash_iter iter)72 util_hash_table_item(struct cso_hash_iter iter)
73 {
74    return (struct util_hash_table_item *)cso_hash_iter_data(iter);
75 }
76 
77 
78 struct util_hash_table *
util_hash_table_create(unsigned (* hash)(void * key),int (* compare)(void * key1,void * key2))79 util_hash_table_create(unsigned (*hash)(void *key),
80                        int (*compare)(void *key1, void *key2))
81 {
82    struct util_hash_table *ht;
83 
84    ht = MALLOC_STRUCT(util_hash_table);
85    if(!ht)
86       return NULL;
87 
88    ht->cso = cso_hash_create();
89    if(!ht->cso) {
90       FREE(ht);
91       return NULL;
92    }
93 
94    ht->hash = hash;
95    ht->compare = compare;
96 
97    return ht;
98 }
99 
100 
101 static INLINE struct cso_hash_iter
util_hash_table_find_iter(struct util_hash_table * ht,void * key,unsigned key_hash)102 util_hash_table_find_iter(struct util_hash_table *ht,
103                           void *key,
104                           unsigned key_hash)
105 {
106    struct cso_hash_iter iter;
107    struct util_hash_table_item *item;
108 
109    iter = cso_hash_find(ht->cso, key_hash);
110    while (!cso_hash_iter_is_null(iter)) {
111       item = (struct util_hash_table_item *)cso_hash_iter_data(iter);
112       if (!ht->compare(item->key, key))
113          break;
114       iter = cso_hash_iter_next(iter);
115    }
116 
117    return iter;
118 }
119 
120 
121 static INLINE struct util_hash_table_item *
util_hash_table_find_item(struct util_hash_table * ht,void * key,unsigned key_hash)122 util_hash_table_find_item(struct util_hash_table *ht,
123                           void *key,
124                           unsigned key_hash)
125 {
126    struct cso_hash_iter iter;
127    struct util_hash_table_item *item;
128 
129    iter = cso_hash_find(ht->cso, key_hash);
130    while (!cso_hash_iter_is_null(iter)) {
131       item = (struct util_hash_table_item *)cso_hash_iter_data(iter);
132       if (!ht->compare(item->key, key))
133          return item;
134       iter = cso_hash_iter_next(iter);
135    }
136 
137    return NULL;
138 }
139 
140 
141 enum pipe_error
util_hash_table_set(struct util_hash_table * ht,void * key,void * value)142 util_hash_table_set(struct util_hash_table *ht,
143                     void *key,
144                     void *value)
145 {
146    unsigned key_hash;
147    struct util_hash_table_item *item;
148    struct cso_hash_iter iter;
149 
150    assert(ht);
151    if (!ht)
152       return PIPE_ERROR_BAD_INPUT;
153 
154    key_hash = ht->hash(key);
155 
156    item = util_hash_table_find_item(ht, key, key_hash);
157    if(item) {
158       /* TODO: key/value destruction? */
159       item->value = value;
160       return PIPE_OK;
161    }
162 
163    item = MALLOC_STRUCT(util_hash_table_item);
164    if(!item)
165       return PIPE_ERROR_OUT_OF_MEMORY;
166 
167    item->key = key;
168    item->value = value;
169 
170    iter = cso_hash_insert(ht->cso, key_hash, item);
171    if(cso_hash_iter_is_null(iter)) {
172       FREE(item);
173       return PIPE_ERROR_OUT_OF_MEMORY;
174    }
175 
176    return PIPE_OK;
177 }
178 
179 
180 void *
util_hash_table_get(struct util_hash_table * ht,void * key)181 util_hash_table_get(struct util_hash_table *ht,
182                     void *key)
183 {
184    unsigned key_hash;
185    struct util_hash_table_item *item;
186 
187    assert(ht);
188    if (!ht)
189       return NULL;
190 
191    key_hash = ht->hash(key);
192 
193    item = util_hash_table_find_item(ht, key, key_hash);
194    if(!item)
195       return NULL;
196 
197    return item->value;
198 }
199 
200 
201 void
util_hash_table_remove(struct util_hash_table * ht,void * key)202 util_hash_table_remove(struct util_hash_table *ht,
203                        void *key)
204 {
205    unsigned key_hash;
206    struct cso_hash_iter iter;
207    struct util_hash_table_item *item;
208 
209    assert(ht);
210    if (!ht)
211       return;
212 
213    key_hash = ht->hash(key);
214 
215    iter = util_hash_table_find_iter(ht, key, key_hash);
216    if(cso_hash_iter_is_null(iter))
217       return;
218 
219    item = util_hash_table_item(iter);
220    assert(item);
221    FREE(item);
222 
223    cso_hash_erase(ht->cso, iter);
224 }
225 
226 
227 void
util_hash_table_clear(struct util_hash_table * ht)228 util_hash_table_clear(struct util_hash_table *ht)
229 {
230    struct cso_hash_iter iter;
231    struct util_hash_table_item *item;
232 
233    assert(ht);
234    if (!ht)
235       return;
236 
237    iter = cso_hash_first_node(ht->cso);
238    while (!cso_hash_iter_is_null(iter)) {
239       item = (struct util_hash_table_item *)cso_hash_take(ht->cso, cso_hash_iter_key(iter));
240       FREE(item);
241       iter = cso_hash_first_node(ht->cso);
242    }
243 }
244 
245 
246 enum pipe_error
util_hash_table_foreach(struct util_hash_table * ht,enum pipe_error (* callback)(void * key,void * value,void * data),void * data)247 util_hash_table_foreach(struct util_hash_table *ht,
248                      enum pipe_error (*callback)
249                         (void *key, void *value, void *data),
250                      void *data)
251 {
252    struct cso_hash_iter iter;
253    struct util_hash_table_item *item;
254    enum pipe_error result;
255 
256    assert(ht);
257    if (!ht)
258       return PIPE_ERROR_BAD_INPUT;
259 
260    iter = cso_hash_first_node(ht->cso);
261    while (!cso_hash_iter_is_null(iter)) {
262       item = (struct util_hash_table_item *)cso_hash_iter_data(iter);
263       result = callback(item->key, item->value, data);
264       if(result != PIPE_OK)
265 	 return result;
266       iter = cso_hash_iter_next(iter);
267    }
268 
269    return PIPE_OK;
270 }
271 
272 
273 void
util_hash_table_destroy(struct util_hash_table * ht)274 util_hash_table_destroy(struct util_hash_table *ht)
275 {
276    struct cso_hash_iter iter;
277    struct util_hash_table_item *item;
278 
279    assert(ht);
280    if (!ht)
281       return;
282 
283    iter = cso_hash_first_node(ht->cso);
284    while (!cso_hash_iter_is_null(iter)) {
285       item = (struct util_hash_table_item *)cso_hash_iter_data(iter);
286       FREE(item);
287       iter = cso_hash_iter_next(iter);
288    }
289 
290    cso_hash_delete(ht->cso);
291 
292    FREE(ht);
293 }
294