summaryrefslogtreecommitdiff
path: root/lib/gl_hash_map.c
blob: c6d3e86c92612217ec8ebbbd4e2c6316a9061bd1 (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
/* Map data type implemented by a hash table.
   Copyright (C) 2006, 2008-2021 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 2018.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

/* Specification.  */
#include "gl_hash_map.h"

#include <stdint.h> /* for uintptr_t, SIZE_MAX */
#include <stdlib.h>

#include "xsize.h"

/* --------------------------- gl_map_t Data Type --------------------------- */

#include "gl_anyhash1.h"

/* Concrete list node implementation, valid for this file only.  */
struct gl_list_node_impl
{
  struct gl_hash_entry h;           /* hash table entry fields; must be first */
  const void *key;
  const void *value;
};
typedef struct gl_list_node_impl * gl_list_node_t;

/* Concrete gl_map_impl type, valid for this file only.  */
struct gl_map_impl
{
  struct gl_map_impl_base base;
  gl_mapkey_hashcode_fn hashcode_fn;
  /* A hash table: managed as an array of collision lists.  */
  struct gl_hash_entry **table;
  size_t table_size;
  /* Number of hash table entries.  */
  size_t count;
};

#define CONTAINER_T gl_map_t
#define CONTAINER_COUNT(map) (map)->count
#include "gl_anyhash2.h"

/* --------------------------- gl_map_t Data Type --------------------------- */

static gl_map_t
gl_hash_nx_create_empty (gl_map_implementation_t implementation,
                         gl_mapkey_equals_fn equals_fn,
                         gl_mapkey_hashcode_fn hashcode_fn,
                         gl_mapkey_dispose_fn kdispose_fn,
                         gl_mapvalue_dispose_fn vdispose_fn)
{
  struct gl_map_impl *map =
    (struct gl_map_impl *) malloc (sizeof (struct gl_map_impl));

  if (map == NULL)
    return NULL;

  map->base.vtable = implementation;
  map->base.equals_fn = equals_fn;
  map->base.kdispose_fn = kdispose_fn;
  map->base.vdispose_fn = vdispose_fn;
  map->hashcode_fn = hashcode_fn;
  map->table_size = 11;
  map->table =
    (gl_hash_entry_t *) calloc (map->table_size, sizeof (gl_hash_entry_t));
  if (map->table == NULL)
    goto fail;
  map->count = 0;

  return map;

 fail:
  free (map);
  return NULL;
}

static size_t _GL_ATTRIBUTE_PURE
gl_hash_size (gl_map_t map)
{
  return map->count;
}

static bool _GL_ATTRIBUTE_PURE
gl_hash_search (gl_map_t map, const void *key, const void **valuep)
{
  size_t hashcode =
    (map->hashcode_fn != NULL
     ? map->hashcode_fn (key)
     : (size_t)(uintptr_t) key);
  size_t bucket = hashcode % map->table_size;
  gl_mapkey_equals_fn equals = map->base.equals_fn;

  /* Look for a match in the hash bucket.  */
  gl_list_node_t node;

  for (node = (gl_list_node_t) map->table[bucket];
       node != NULL;
       node = (gl_list_node_t) node->h.hash_next)
    if (node->h.hashcode == hashcode
        && (equals != NULL
            ? equals (key, node->key)
            : key == node->key))
      {
        *valuep = node->value;
        return true;
      }
  return false;
}

static int
gl_hash_nx_getput (gl_map_t map, const void *key, const void *value,
                   const void **oldvaluep)
{
  size_t hashcode =
    (map->hashcode_fn != NULL
     ? map->hashcode_fn (key)
     : (size_t)(uintptr_t) key);
  size_t bucket = hashcode % map->table_size;
  gl_mapkey_equals_fn equals = map->base.equals_fn;

  /* Look for a match in the hash bucket.  */
  {
    gl_list_node_t node;

    for (node = (gl_list_node_t) map->table[bucket];
         node != NULL;
         node = (gl_list_node_t) node->h.hash_next)
      if (node->h.hashcode == hashcode
          && (equals != NULL
              ? equals (key, node->key)
              : key == node->key))
        {
          *oldvaluep = node->value;
          node->value = value;
          return 0;
        }
  }

  /* Allocate a new node.  */
  gl_list_node_t node =
    (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl));

  if (node == NULL)
    return -1;

  node->key = key;
  node->value = value;
  node->h.hashcode = hashcode;

  /* Add node to the hash table.  */
  node->h.hash_next = map->table[bucket];
  map->table[bucket] = &node->h;

  /* Add node to the map.  */
  map->count++;

  hash_resize_after_add (map);

  return 1;
}

static bool
gl_hash_getremove (gl_map_t map, const void *key, const void **oldvaluep)
{
  size_t hashcode =
    (map->hashcode_fn != NULL
     ? map->hashcode_fn (key)
     : (size_t)(uintptr_t) key);
  size_t bucket = hashcode % map->table_size;
  gl_mapkey_equals_fn equals = map->base.equals_fn;

  /* Look for the first match in the hash bucket.  */
  gl_list_node_t *nodep;

  for (nodep = (gl_list_node_t *) &map->table[bucket];
       *nodep != NULL;
       nodep = (gl_list_node_t *) &(*nodep)->h.hash_next)
    {
      gl_list_node_t node = *nodep;
      if (node->h.hashcode == hashcode
          && (equals != NULL
              ? equals (key, node->key)
              : key == node->key))
        {
          *oldvaluep = node->value;

          /* Remove node from the hash table.  */
          *nodep = (gl_list_node_t) node->h.hash_next;

          /* Remove node from the map.  */
          map->count--;

          if (map->base.kdispose_fn != NULL)
            map->base.kdispose_fn (node->key);
          free (node);
          return true;
        }
    }

  return false;
}

static void
gl_hash_free (gl_map_t map)
{
  if (map->count > 0)
    {
      gl_mapkey_dispose_fn kdispose = map->base.kdispose_fn;
      gl_mapvalue_dispose_fn vdispose = map->base.vdispose_fn;
      struct gl_hash_entry **table = map->table;
      size_t i;

      for (i = map->table_size; i > 0; )
        {
          gl_hash_entry_t node = table[--i];

          while (node != NULL)
            {
              gl_hash_entry_t next = node->hash_next;

              /* Free the entry.  */
              if (vdispose != NULL)
                vdispose (((gl_list_node_t) node)->value);
              if (kdispose != NULL)
                kdispose (((gl_list_node_t) node)->key);
              free (node);

              node = next;
            }
        }
    }

  free (map->table);
  free (map);
}

/* ---------------------- gl_map_iterator_t Data Type ---------------------- */

/* Here we iterate through the hash buckets.  Therefore the order in which the
   pairs are returned is unpredictable.  */

static gl_map_iterator_t
gl_hash_iterator (gl_map_t map)
{
  gl_map_iterator_t result;

  result.vtable = map->base.vtable;
  result.map = map;
  result.p = NULL;         /* runs through the nodes of a bucket */
  result.i = 0;            /* index of the bucket that p points into + 1 */
  result.j = map->table_size;
#if defined GCC_LINT || defined lint
  result.q = NULL;
  result.count = 0;
#endif

  return result;
}

static bool
gl_hash_iterator_next (gl_map_iterator_t *iterator,
                       const void **keyp, const void **valuep)
{
  if (iterator->p != NULL)
    {
      /* We're traversing a bucket.  */
      gl_list_node_t node = (gl_list_node_t) iterator->p;
      *keyp = node->key;
      *valuep = node->value;
      iterator->p = (gl_list_node_t) node->h.hash_next;
      return true;
    }
  else
    {
      /* Find the next bucket that is not empty.  */
      size_t j = iterator->j;
      size_t i = iterator->i;

      if (i < j)
        {
          gl_hash_entry_t *table = iterator->map->table;
          do
            {
              gl_list_node_t node = (gl_list_node_t) table[i++];
              if (node != NULL)
                {
                  *keyp = node->key;
                  *valuep = node->value;
                  iterator->p = (gl_list_node_t) node->h.hash_next;
                  iterator->i = i;
                  return true;
                }
            }
          while (i < j);
        }
      /* Here iterator->p is still NULL, and i == j.  */
      iterator->i = j;
      return false;
    }
}

static void
gl_hash_iterator_free (gl_map_iterator_t *iterator)
{
}


const struct gl_map_implementation gl_hash_map_implementation =
  {
    gl_hash_nx_create_empty,
    gl_hash_size,
    gl_hash_search,
    gl_hash_nx_getput,
    gl_hash_getremove,
    gl_hash_free,
    gl_hash_iterator,
    gl_hash_iterator_next,
    gl_hash_iterator_free
  };