summaryrefslogtreecommitdiffstats
path: root/Utilities/cmcurl/lib/hash.c
blob: c99b1b6994884ac665c36d0f6700db43383dfc25 (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
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

#include "curl_setup.h"

#include <curl/curl.h>

#include "hash.h"
#include "llist.h"
#include "curl_memory.h"

/* The last #include file should be: */
#include "memdebug.h"

static void
hash_element_dtor(void *user, void *element)
{
  struct curl_hash *h = (struct curl_hash *) user;
  struct curl_hash_element *e = (struct curl_hash_element *) element;

  if(e->ptr) {
    h->dtor(e->ptr);
    e->ptr = NULL;
  }

  e->key_len = 0;

  free(e);
}

/* Initializes a hash structure.
 * Return 1 on error, 0 is fine.
 *
 * @unittest: 1602
 * @unittest: 1603
 */
int
Curl_hash_init(struct curl_hash *h,
               int slots,
               hash_function hfunc,
               comp_function comparator,
               curl_hash_dtor dtor)
{
  int i;

  if(!slots || !hfunc || !comparator ||!dtor) {
    return 1; /* failure */
  }

  h->hash_func = hfunc;
  h->comp_func = comparator;
  h->dtor = dtor;
  h->size = 0;
  h->slots = slots;

  h->table = malloc(slots * sizeof(struct curl_llist));
  if(h->table) {
    for(i = 0; i < slots; ++i)
      Curl_llist_init(&h->table[i], (curl_llist_dtor) hash_element_dtor);
    return 0; /* fine */
  }
  h->slots = 0;
  return 1; /* failure */
}

static struct curl_hash_element *
mk_hash_element(const void *key, size_t key_len, const void *p)
{
  /* allocate the struct plus memory after it to store the key */
  struct curl_hash_element *he = malloc(sizeof(struct curl_hash_element) +
                                        key_len);
  if(he) {
    /* copy the key */
    memcpy(he->key, key, key_len);
    he->key_len = key_len;
    he->ptr = (void *) p;
  }
  return he;
}

#define FETCH_LIST(x,y,z) &x->table[x->hash_func(y, z, x->slots)]

/* Insert the data in the hash. If there already was a match in the hash,
 * that data is replaced.
 *
 * @unittest: 1305
 * @unittest: 1602
 * @unittest: 1603
 */
void *
Curl_hash_add(struct curl_hash *h, void *key, size_t key_len, void *p)
{
  struct curl_hash_element  *he;
  struct curl_llist_element *le;
  struct curl_llist *l = FETCH_LIST(h, key, key_len);

  for(le = l->head; le; le = le->next) {
    he = (struct curl_hash_element *) le->ptr;
    if(h->comp_func(he->key, he->key_len, key, key_len)) {
      Curl_llist_remove(l, le, (void *)h);
      --h->size;
      break;
    }
  }

  he = mk_hash_element(key, key_len, p);
  if(he) {
    Curl_llist_insert_next(l, l->tail, he, &he->list);
    ++h->size;
    return p; /* return the new entry */
  }

  return NULL; /* failure */
}

/* Remove the identified hash entry.
 * Returns non-zero on failure.
 *
 * @unittest: 1603
 */
int Curl_hash_delete(struct curl_hash *h, void *key, size_t key_len)
{
  struct curl_llist_element *le;
  struct curl_hash_element  *he;
  struct curl_llist *l = FETCH_LIST(h, key, key_len);

  for(le = l->head; le; le = le->next) {
    he = le->ptr;
    if(h->comp_func(he->key, he->key_len, key, key_len)) {
      Curl_llist_remove(l, le, (void *) h);
      --h->size;
      return 0;
    }
  }
  return 1;
}

/* Retrieves a hash element.
 *
 * @unittest: 1603
 */
void *
Curl_hash_pick(struct curl_hash *h, void *key, size_t key_len)
{
  struct curl_llist_element *le;
  struct curl_hash_element  *he;
  struct curl_llist *l;

  if(h) {
    l = FETCH_LIST(h, key, key_len);
    for(le = l->head; le; le = le->next) {
      he = le->ptr;
      if(h->comp_func(he->key, he->key_len, key, key_len)) {
        return he->ptr;
      }
    }
  }

  return NULL;
}

#if defined(DEBUGBUILD) && defined(AGGRESIVE_TEST)
void
Curl_hash_apply(curl_hash *h, void *user,
                void (*cb)(void *user, void *ptr))
{
  struct curl_llist_element  *le;
  int                  i;

  for(i = 0; i < h->slots; ++i) {
    for(le = (h->table[i])->head;
        le;
        le = le->next) {
      curl_hash_element *el = le->ptr;
      cb(user, el->ptr);
    }
  }
}
#endif

/* Destroys all the entries in the given hash and resets its attributes,
 * prepping the given hash for [static|dynamic] deallocation.
 *
 * @unittest: 1305
 * @unittest: 1602
 * @unittest: 1603
 */
void
Curl_hash_destroy(struct curl_hash *h)
{
  int i;

  for(i = 0; i < h->slots; ++i) {
    Curl_llist_destroy(&h->table[i], (void *) h);
  }

  Curl_safefree(h->table);
  h->size = 0;
  h->slots = 0;
}

/* Removes all the entries in the given hash.
 *
 * @unittest: 1602
 */
void
Curl_hash_clean(struct curl_hash *h)
{
  Curl_hash_clean_with_criterium(h, NULL, NULL);
}

/* Cleans all entries that pass the comp function criteria. */
void
Curl_hash_clean_with_criterium(struct curl_hash *h, void *user,
                               int (*comp)(void *, void *))
{
  struct curl_llist_element *le;
  struct curl_llist_element *lnext;
  struct curl_llist *list;
  int i;

  if(!h)
    return;

  for(i = 0; i < h->slots; ++i) {
    list = &h->table[i];
    le = list->head; /* get first list entry */
    while(le) {
      struct curl_hash_element *he = le->ptr;
      lnext = le->next;
      /* ask the callback function if we shall remove this entry or not */
      if(comp == NULL || comp(user, he->ptr)) {
        Curl_llist_remove(list, le, (void *) h);
        --h->size; /* one less entry in the hash now */
      }
      le = lnext;
    }
  }
}

size_t Curl_hash_str(void *key, size_t key_length, size_t slots_num)
{
  const char *key_str = (const char *) key;
  const char *end = key_str + key_length;
  unsigned long h = 5381;

  while(key_str < end) {
    h += h << 5;
    h ^= (unsigned long) *key_str++;
  }

  return (h % slots_num);
}

size_t Curl_str_key_compare(void *k1, size_t key1_len,
                            void *k2, size_t key2_len)
{
  if((key1_len == key2_len) && !memcmp(k1, k2, key1_len))
    return 1;

  return 0;
}

void Curl_hash_start_iterate(struct curl_hash *hash,
                             struct curl_hash_iterator *iter)
{
  iter->hash = hash;
  iter->slot_index = 0;
  iter->current_element = NULL;
}

struct curl_hash_element *
Curl_hash_next_element(struct curl_hash_iterator *iter)
{
  int i;
  struct curl_hash *h = iter->hash;

  /* Get the next element in the current list, if any */
  if(iter->current_element)
    iter->current_element = iter->current_element->next;

  /* If we have reached the end of the list, find the next one */
  if(!iter->current_element) {
    for(i = iter->slot_index; i < h->slots; i++) {
      if(h->table[i].head) {
        iter->current_element = h->table[i].head;
        iter->slot_index = i + 1;
        break;
      }
    }
  }

  if(iter->current_element) {
    struct curl_hash_element *he = iter->current_element->ptr;
    return he;
  }
  iter->current_element = NULL;
  return NULL;
}

#if 0 /* useful function for debugging hashes and their contents */
void Curl_hash_print(struct curl_hash *h,
                     void (*func)(void *))
{
  struct curl_hash_iterator iter;
  struct curl_hash_element *he;
  int last_index = -1;

  if(!h)
    return;

  fprintf(stderr, "=Hash dump=\n");

  Curl_hash_start_iterate(h, &iter);

  he = Curl_hash_next_element(&iter);
  while(he) {
    if(iter.slot_index != last_index) {
      fprintf(stderr, "index %d:", iter.slot_index);
      if(last_index >= 0) {
        fprintf(stderr, "\n");
      }
      last_index = iter.slot_index;
    }

    if(func)
      func(he->ptr);
    else
      fprintf(stderr, " [%p]", (void *)he->ptr);

    he = Curl_hash_next_element(&iter);
  }
  fprintf(stderr, "\n");
}
#endif