summaryrefslogtreecommitdiff
path: root/amdgpu/util_hash.c
blob: 87cb671b6a03a537187079484c7a9663953b0f41 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
/**************************************************************************
 *
 * Copyright 2007 VMware, Inc.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/

 /*
  * Authors:
  *   Zack Rusin <zackr@vmware.com>
  */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "util_hash.h"

#include <stdlib.h>
#include <assert.h>

#define MAX(a, b) ((a > b) ? (a) : (b))

static const int MinNumBits = 4;

static const unsigned char prime_deltas[] = {
	0,  0,  1,  3,  1,  5,  3,  3,  1,  9,  7,  5,  3,  9, 25,  3,
	1, 21,  3, 21,  7, 15,  9,  5,  3, 29, 15,  0,  0,  0,  0,  0
};

static int primeForNumBits(int numBits)
{
	return (1 << numBits) + prime_deltas[numBits];
}

/* Returns the smallest integer n such that
   primeForNumBits(n) >= hint.
*/
static int countBits(int hint)
{
	int numBits = 0;
	int bits = hint;

	while (bits > 1) {
		bits >>= 1;
		numBits++;
	}

	if (numBits >= (int)sizeof(prime_deltas)) {
		numBits = sizeof(prime_deltas) - 1;
	} else if (primeForNumBits(numBits) < hint) {
		++numBits;
	}
	return numBits;
}

struct util_node {
   struct util_node *next;
   unsigned key;
   void *value;
};

struct util_hash_data {
   struct util_node *fakeNext;
   struct util_node **buckets;
   int size;
   int nodeSize;
   short userNumBits;
   short numBits;
   int numBuckets;
};

struct util_hash {
   union {
      struct util_hash_data *d;
      struct util_node      *e;
   } data;
};

static void *util_data_allocate_node(struct util_hash_data *hash)
{
   return malloc(hash->nodeSize);
}

static void util_free_node(struct util_node *node)
{
   free(node);
}

static struct util_node *
util_hash_create_node(struct util_hash *hash,
                      unsigned akey, void *avalue,
                      struct util_node **anextNode)
{
   struct util_node *node = util_data_allocate_node(hash->data.d);

   if (!node)
      return NULL;

   node->key = akey;
   node->value = avalue;

   node->next = (struct util_node*)(*anextNode);
   *anextNode = node;
   ++hash->data.d->size;
   return node;
}

static void util_data_rehash(struct util_hash_data *hash, int hint)
{
   if (hint < 0) {
      hint = countBits(-hint);
      if (hint < MinNumBits)
         hint = MinNumBits;
      hash->userNumBits = (short)hint;
      while (primeForNumBits(hint) < (hash->size >> 1))
         ++hint;
   } else if (hint < MinNumBits) {
      hint = MinNumBits;
   }

   if (hash->numBits != hint) {
      struct util_node *e = (struct util_node *)(hash);
      struct util_node **oldBuckets = hash->buckets;
      int oldNumBuckets = hash->numBuckets;
      int  i = 0;

      hash->numBits = (short)hint;
      hash->numBuckets = primeForNumBits(hint);
      hash->buckets = malloc(sizeof(struct util_node*) * hash->numBuckets);
      for (i = 0; i < hash->numBuckets; ++i)
         hash->buckets[i] = e;

      for (i = 0; i < oldNumBuckets; ++i) {
         struct util_node *firstNode = oldBuckets[i];
         while (firstNode != e) {
            unsigned h = firstNode->key;
            struct util_node *lastNode = firstNode;
            struct util_node *afterLastNode;
            struct util_node **beforeFirstNode;
            
            while (lastNode->next != e && lastNode->next->key == h)
               lastNode = lastNode->next;

            afterLastNode = lastNode->next;
            beforeFirstNode = &hash->buckets[h % hash->numBuckets];
            while (*beforeFirstNode != e)
               beforeFirstNode = &(*beforeFirstNode)->next;
            lastNode->next = *beforeFirstNode;
            *beforeFirstNode = firstNode;
            firstNode = afterLastNode;
         }
      }
      free(oldBuckets);
   }
}

static void util_data_might_grow(struct util_hash_data *hash)
{
   if (hash->size >= hash->numBuckets)
      util_data_rehash(hash, hash->numBits + 1);
}

static void util_data_has_shrunk(struct util_hash_data *hash)
{
   if (hash->size <= (hash->numBuckets >> 3) &&
       hash->numBits > hash->userNumBits) {
      int max = MAX(hash->numBits-2, hash->userNumBits);
      util_data_rehash(hash,  max);
   }
}

static struct util_node *util_data_first_node(struct util_hash_data *hash)
{
   struct util_node *e = (struct util_node *)(hash);
   struct util_node **bucket = hash->buckets;
   int n = hash->numBuckets;
   while (n--) {
      if (*bucket != e)
         return *bucket;
      ++bucket;
   }
   return e;
}

static struct util_node **util_hash_find_node(struct util_hash *hash, unsigned akey)
{
   struct util_node **node;

   if (hash->data.d->numBuckets) {
      node = (struct util_node **)(&hash->data.d->buckets[akey % hash->data.d->numBuckets]);
      assert(*node == hash->data.e || (*node)->next);
      while (*node != hash->data.e && (*node)->key != akey)
         node = &(*node)->next;
   } else {
      node = (struct util_node **)((const struct util_node * const *)(&hash->data.e));
   }
   return node;
}

drm_private struct util_hash_iter
util_hash_insert(struct util_hash *hash, unsigned key, void *data)
{
   util_data_might_grow(hash->data.d);

   {
      struct util_node **nextNode = util_hash_find_node(hash, key);
      struct util_node *node = util_hash_create_node(hash, key, data, nextNode);
      if (!node) {
         struct util_hash_iter null_iter = {hash, 0};
         return null_iter;
      }

      {
         struct util_hash_iter iter = {hash, node};
         return iter;
      }
   }
}

drm_private struct util_hash *util_hash_create(void)
{
   struct util_hash *hash = malloc(sizeof(struct util_hash));
   if (!hash)
      return NULL;

   hash->data.d = malloc(sizeof(struct util_hash_data));
   if (!hash->data.d) {
      free(hash);
      return NULL;
   }

   hash->data.d->fakeNext = 0;
   hash->data.d->buckets = 0;
   hash->data.d->size = 0;
   hash->data.d->nodeSize = sizeof(struct util_node);
   hash->data.d->userNumBits = (short)MinNumBits;
   hash->data.d->numBits = 0;
   hash->data.d->numBuckets = 0;

   return hash;
}

drm_private void util_hash_delete(struct util_hash *hash)
{
   struct util_node *e_for_x = (struct util_node *)(hash->data.d);
   struct util_node **bucket = (struct util_node **)(hash->data.d->buckets);
   int n = hash->data.d->numBuckets;
   while (n--) {
      struct util_node *cur = *bucket++;
      while (cur != e_for_x) {
         struct util_node *next = cur->next;
         util_free_node(cur);
         cur = next;
      }
   }
   free(hash->data.d->buckets);
   free(hash->data.d);
   free(hash);
}

drm_private struct util_hash_iter
util_hash_find(struct util_hash *hash, unsigned key)
{
   struct util_node **nextNode = util_hash_find_node(hash, key);
   struct util_hash_iter iter = {hash, *nextNode};
   return iter;
}

drm_private unsigned util_hash_iter_key(struct util_hash_iter iter)
{
   if (!iter.node || iter.hash->data.e == iter.node)
      return 0;
   return iter.node->key;
}

drm_private void *util_hash_iter_data(struct util_hash_iter iter)
{
   if (!iter.node || iter.hash->data.e == iter.node)
      return 0;
   return iter.node->value;
}

static struct util_node *util_hash_data_next(struct util_node *node)
{
   union {
      struct util_node *next;
      struct util_node *e;
      struct util_hash_data *d;
   } a;
   int start;
   struct util_node **bucket;
   int n;

   a.next = node->next;
   if (!a.next) {
      /* iterating beyond the last element */
      return 0;
   }
   if (a.next->next)
      return a.next;

   start = (node->key % a.d->numBuckets) + 1;
   bucket = a.d->buckets + start;
   n = a.d->numBuckets - start;
   while (n--) {
      if (*bucket != a.e)
         return *bucket;
      ++bucket;
   }
   return a.e;
}

drm_private struct util_hash_iter
util_hash_iter_next(struct util_hash_iter iter)
{
   struct util_hash_iter next = {iter.hash, util_hash_data_next(iter.node)};
   return next;
}

drm_private int util_hash_iter_is_null(struct util_hash_iter iter)
{
   if (!iter.node || iter.node == iter.hash->data.e)
      return 1;
   return 0;
}

drm_private void *util_hash_take(struct util_hash *hash, unsigned akey)
{
   struct util_node **node = util_hash_find_node(hash, akey);
   if (*node != hash->data.e) {
      void *t = (*node)->value;
      struct util_node *next = (*node)->next;
      util_free_node(*node);
      *node = next;
      --hash->data.d->size;
      util_data_has_shrunk(hash->data.d);
      return t;
   }
   return 0;
}

drm_private struct util_hash_iter util_hash_first_node(struct util_hash *hash)
{
   struct util_hash_iter iter = {hash, util_data_first_node(hash->data.d)};
   return iter;
}

drm_private struct util_hash_iter
util_hash_erase(struct util_hash *hash, struct util_hash_iter iter)
{
   struct util_hash_iter ret = iter;
   struct util_node *node = iter.node;
   struct util_node **node_ptr;

   if (node == hash->data.e)
      return iter;

   ret = util_hash_iter_next(ret);
   node_ptr = (struct util_node**)(&hash->data.d->buckets[node->key % hash->data.d->numBuckets]);
   while (*node_ptr != node)
      node_ptr = &(*node_ptr)->next;
   *node_ptr = node->next;
   util_free_node(node);
   --hash->data.d->size;
   return ret;
}