1 /*
2  * Copyright (c) 2004 Stefan Walter
3  * Copyright (c) 2011 Collabora Ltd.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  *     * Redistributions of source code must retain the above
10  *       copyright notice, this list of conditions and the
11  *       following disclaimer.
12  *     * Redistributions in binary form must reproduce the
13  *       above copyright notice, this list of conditions and
14  *       the following disclaimer in the documentation and/or
15  *       other materials provided with the distribution.
16  *     * The names of contributors to this software may not be
17  *       used to endorse or promote products derived from this
18  *       software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
31  * DAMAGE.
32  */
33 
34 #include "config.h"
35 
36 #include "debug.h"
37 #include "dict.h"
38 #include "hash.h"
39 
40 #include <sys/types.h>
41 
42 #include <assert.h>
43 #include <stdint.h>
44 #include <stdlib.h>
45 #include <string.h>
46 
47 struct _p11_dict {
48 	p11_dict_hasher hash_func;
49 	p11_dict_equals equal_func;
50 	p11_destroyer key_destroy_func;
51 	p11_destroyer value_destroy_func;
52 
53 	struct _p11_dictbucket **buckets;
54 	unsigned int num_items;
55 	unsigned int num_buckets;
56 };
57 
58 typedef struct _p11_dictbucket {
59 	void *key;
60 	unsigned int hashed;
61 	void *value;
62 	struct _p11_dictbucket *next;
63 } dictbucket;
64 
65 static dictbucket *
next_entry(p11_dictiter * iter)66 next_entry (p11_dictiter *iter)
67 {
68 	dictbucket *bucket = iter->next;
69 	while (!bucket) {
70 		if (iter->index >= iter->dict->num_buckets)
71 			return NULL;
72 		bucket = iter->dict->buckets[iter->index++];
73 	}
74 	iter->next = bucket->next;
75 	return bucket;
76 }
77 
78 
79 bool
p11_dict_next(p11_dictiter * iter,void ** key,void ** value)80 p11_dict_next (p11_dictiter *iter,
81                void **key,
82                void **value)
83 {
84 	dictbucket *bucket = next_entry (iter);
85 	if (bucket == NULL)
86 		return false;
87 	if (key)
88 		*key = bucket->key;
89 	if (value)
90 		*value = bucket->value;
91 	return true;
92 }
93 
94 void
p11_dict_iterate(p11_dict * dict,p11_dictiter * iter)95 p11_dict_iterate (p11_dict *dict,
96                   p11_dictiter *iter)
97 {
98 	iter->dict = dict;
99 	iter->index = 0;
100 	iter->next = NULL;
101 }
102 
103 static dictbucket **
lookup_or_create_bucket(p11_dict * dict,const void * key,bool create)104 lookup_or_create_bucket (p11_dict *dict,
105                          const void *key,
106                          bool create)
107 {
108 	dictbucket **bucketp;
109 	unsigned int hash;
110 
111 	/* Perform the hashing */
112 	hash = dict->hash_func (key);
113 
114 	/* scan linked list */
115 	for (bucketp = &dict->buckets[hash % dict->num_buckets];
116 	     *bucketp != NULL; bucketp = &(*bucketp)->next) {
117 		if((*bucketp)->hashed == hash && dict->equal_func ((*bucketp)->key, key))
118 			break;
119 	}
120 
121 	if ((*bucketp) != NULL || !create)
122 		return bucketp;
123 
124 	/* add a new entry for non-NULL val */
125 	(*bucketp) = calloc (1, sizeof (dictbucket));
126 
127 	if (*bucketp != NULL) {
128 		(*bucketp)->key = (void*)key;
129 		(*bucketp)->hashed = hash;
130 		dict->num_items++;
131 	}
132 
133 	return bucketp;
134 }
135 
136 void *
p11_dict_get(p11_dict * dict,const void * key)137 p11_dict_get (p11_dict *dict,
138               const void *key)
139 {
140 	dictbucket **bucketp;
141 
142 	bucketp = lookup_or_create_bucket (dict, key, false);
143 	if (bucketp && *bucketp)
144 		return (void*)((*bucketp)->value);
145 	else
146 		return NULL;
147 }
148 
149 bool
p11_dict_set(p11_dict * dict,void * key,void * val)150 p11_dict_set (p11_dict *dict,
151               void *key,
152               void *val)
153 {
154 	dictbucket **bucketp;
155 	p11_dictiter iter;
156 	dictbucket *bucket;
157 	dictbucket **new_buckets;
158 	unsigned int num_buckets;
159 
160 	bucketp = lookup_or_create_bucket (dict, key, true);
161 	if(bucketp && *bucketp) {
162 
163 		/* Destroy the previous key */
164 		if ((*bucketp)->key && (*bucketp)->key != key && dict->key_destroy_func)
165 			dict->key_destroy_func ((*bucketp)->key);
166 
167 		/* Destroy the previous value */
168 		if ((*bucketp)->value && (*bucketp)->value != val && dict->value_destroy_func)
169 			dict->value_destroy_func ((*bucketp)->value);
170 
171 		/* replace entry */
172 		(*bucketp)->key = key;
173 		(*bucketp)->value = val;
174 
175 		/* check that the collision rate isn't too high */
176 		if (dict->num_items > dict->num_buckets) {
177 			num_buckets = dict->num_buckets * 2 + 1;
178 			new_buckets = (dictbucket **)calloc (num_buckets, sizeof (dictbucket *));
179 
180 			/* Ignore failures, maybe we can expand later */
181 			if(new_buckets) {
182 				p11_dict_iterate (dict, &iter);
183 				while ((bucket = next_entry (&iter)) != NULL) {
184 					unsigned int i = bucket->hashed % num_buckets;
185 					bucket->next = new_buckets[i];
186 					new_buckets[i] = bucket;
187 				}
188 
189 				free (dict->buckets);
190 				dict->buckets = new_buckets;
191 				dict->num_buckets = num_buckets;
192 			}
193 		}
194 
195 		return true;
196 	}
197 
198 	return_val_if_reached (false);
199 }
200 
201 bool
p11_dict_steal(p11_dict * dict,const void * key,void ** stolen_key,void ** stolen_value)202 p11_dict_steal (p11_dict *dict,
203                 const void *key,
204                 void **stolen_key,
205                 void **stolen_value)
206 {
207 	dictbucket **bucketp;
208 
209 	bucketp = lookup_or_create_bucket (dict, key, false);
210 	if (bucketp && *bucketp) {
211 		dictbucket *old = *bucketp;
212 		*bucketp = (*bucketp)->next;
213 		--dict->num_items;
214 		if (stolen_key)
215 			*stolen_key = old->key;
216 		if (stolen_value)
217 			*stolen_value = old->value;
218 		free (old);
219 		return true;
220 	}
221 
222 	return false;
223 
224 }
225 
226 bool
p11_dict_remove(p11_dict * dict,const void * key)227 p11_dict_remove (p11_dict *dict,
228                  const void *key)
229 {
230 	void *old_key;
231 	void *old_value;
232 
233 	if (!p11_dict_steal (dict, key, &old_key, &old_value))
234 		return false;
235 
236 	if (dict->key_destroy_func)
237 		dict->key_destroy_func (old_key);
238 	if (dict->value_destroy_func)
239 		dict->value_destroy_func (old_value);
240 	return true;
241 }
242 
243 void
p11_dict_clear(p11_dict * dict)244 p11_dict_clear (p11_dict *dict)
245 {
246 	dictbucket *bucket, *next;
247 	unsigned int i;
248 
249 	/* Free all entries in the array */
250 	for (i = 0; i < dict->num_buckets; ++i) {
251 		bucket = dict->buckets[i];
252 		while (bucket != NULL) {
253 			next = bucket->next;
254 			if (dict->key_destroy_func)
255 				dict->key_destroy_func (bucket->key);
256 			if (dict->value_destroy_func)
257 				dict->value_destroy_func (bucket->value);
258 			free (bucket);
259 			bucket = next;
260 		}
261 	}
262 
263 	memset (dict->buckets, 0, dict->num_buckets * sizeof (dictbucket *));
264 	dict->num_items = 0;
265 }
266 
267 p11_dict *
p11_dict_new(p11_dict_hasher hash_func,p11_dict_equals equal_func,p11_destroyer key_destroy_func,p11_destroyer value_destroy_func)268 p11_dict_new (p11_dict_hasher hash_func,
269               p11_dict_equals equal_func,
270               p11_destroyer key_destroy_func,
271               p11_destroyer value_destroy_func)
272 {
273 	p11_dict *dict;
274 
275 	assert (hash_func);
276 	assert (equal_func);
277 
278 	dict = malloc (sizeof (p11_dict));
279 	if (dict) {
280 		dict->hash_func = hash_func;
281 		dict->equal_func = equal_func;
282 		dict->key_destroy_func = key_destroy_func;
283 		dict->value_destroy_func = value_destroy_func;
284 
285 		dict->num_buckets = 9;
286 		dict->buckets = (dictbucket **)calloc (dict->num_buckets, sizeof (dictbucket *));
287 		if (!dict->buckets) {
288 			free (dict);
289 			return NULL;
290 		}
291 
292 		dict->num_items = 0;
293 	}
294 
295 	return dict;
296 }
297 
298 void
p11_dict_free(p11_dict * dict)299 p11_dict_free (p11_dict *dict)
300 {
301 	dictbucket *bucket;
302 	p11_dictiter iter;
303 
304 	if (!dict)
305 		return;
306 
307 	p11_dict_iterate (dict, &iter);
308 	while ((bucket = next_entry (&iter)) != NULL) {
309 		if (dict->key_destroy_func)
310 			dict->key_destroy_func (bucket->key);
311 		if (dict->value_destroy_func)
312 			dict->value_destroy_func (bucket->value);
313 		free (bucket);
314 	}
315 
316 	if (dict->buckets)
317 		free (dict->buckets);
318 
319 	free (dict);
320 }
321 
322 unsigned int
p11_dict_size(p11_dict * dict)323 p11_dict_size (p11_dict *dict)
324 {
325 	return dict->num_items;
326 }
327 
328 unsigned int
p11_dict_str_hash(const void * string)329 p11_dict_str_hash (const void *string)
330 {
331 	uint32_t hash;
332 	p11_hash_murmur3 (&hash, string, strlen (string), NULL);
333 	return hash;
334 }
335 
336 bool
p11_dict_str_equal(const void * string_one,const void * string_two)337 p11_dict_str_equal (const void *string_one,
338                     const void *string_two)
339 {
340 	assert (string_one);
341 	assert (string_two);
342 
343 	return strcmp (string_one, string_two) == 0;
344 }
345 
346 unsigned int
p11_dict_ulongptr_hash(const void * to_ulong)347 p11_dict_ulongptr_hash (const void *to_ulong)
348 {
349 	assert (to_ulong);
350 	return (unsigned int)*((unsigned long*)to_ulong);
351 }
352 
353 bool
p11_dict_ulongptr_equal(const void * ulong_one,const void * ulong_two)354 p11_dict_ulongptr_equal (const void *ulong_one,
355                          const void *ulong_two)
356 {
357 	assert (ulong_one);
358 	assert (ulong_two);
359 	return *((unsigned long*)ulong_one) == *((unsigned long*)ulong_two);
360 }
361 
362 unsigned int
p11_dict_intptr_hash(const void * to_int)363 p11_dict_intptr_hash (const void *to_int)
364 {
365 	assert (to_int);
366 	return (unsigned int)*((int*)to_int);
367 }
368 
369 bool
p11_dict_intptr_equal(const void * int_one,const void * int_two)370 p11_dict_intptr_equal (const void *int_one,
371                         const void *int_two)
372 {
373 	assert (int_one);
374 	assert (int_two);
375 	return *((int*)int_one) == *((int*)int_two);
376 }
377 
378 unsigned int
p11_dict_direct_hash(const void * ptr)379 p11_dict_direct_hash (const void *ptr)
380 {
381 	return (unsigned int)(size_t)ptr;
382 }
383 
384 bool
p11_dict_direct_equal(const void * ptr_one,const void * ptr_two)385 p11_dict_direct_equal (const void *ptr_one,
386                        const void *ptr_two)
387 {
388 	return ptr_one == ptr_two;
389 }
390