Coverage Report

Created: 2025-12-05 06:31

next uncovered line (L), next uncovered region (R), next uncovered branch (B)
/src/libyang/src/hash_table.c
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Count
Source
1
/**
2
 * @file hash_table.c
3
 * @author Radek Krejci <rkrejci@cesnet.cz>
4
 * @brief libyang dictionary for storing strings and generic hash table
5
 *
6
 * Copyright (c) 2015 - 2018 CESNET, z.s.p.o.
7
 *
8
 * This source code is licensed under BSD 3-Clause License (the "License").
9
 * You may not use this file except in compliance with the License.
10
 * You may obtain a copy of the License at
11
 *
12
 *     https://opensource.org/licenses/BSD-3-Clause
13
 */
14
15
#include "hash_table.h"
16
17
#include <assert.h>
18
#include <pthread.h>
19
#include <stdint.h>
20
#include <stdlib.h>
21
#include <string.h>
22
23
#include "common.h"
24
#include "compat.h"
25
#include "dict.h"
26
#include "log.h"
27
28
0
#define LYDICT_MIN_SIZE 1024
29
30
/**
31
 * @brief Comparison callback for dictionary's hash table
32
 *
33
 * Implementation of ::lyht_value_equal_cb.
34
 */
35
static ly_bool
36
lydict_val_eq(void *val1_p, void *val2_p, ly_bool UNUSED(mod), void *cb_data)
37
0
{
38
0
    LY_CHECK_ARG_RET(NULL, val1_p, val2_p, cb_data, 0);
39
40
0
    const char *str1 = ((struct dict_rec *)val1_p)->value;
41
0
    const char *str2 = ((struct dict_rec *)val2_p)->value;
42
43
0
    LY_CHECK_ERR_RET(!str1, LOGARG(NULL, val1_p), 0);
44
0
    LY_CHECK_ERR_RET(!str2, LOGARG(NULL, val2_p), 0);
45
46
0
    if (strncmp(str1, str2, *(size_t *)cb_data) == 0) {
47
0
        return 1;
48
0
    }
49
50
0
    return 0;
51
0
}
52
53
void
54
lydict_init(struct dict_table *dict)
55
0
{
56
0
    LY_CHECK_ARG_RET(NULL, dict, );
57
58
0
    dict->hash_tab = lyht_new(LYDICT_MIN_SIZE, sizeof(struct dict_rec), lydict_val_eq, NULL, 1);
59
0
    LY_CHECK_ERR_RET(!dict->hash_tab, LOGINT(NULL), );
60
0
    pthread_mutex_init(&dict->lock, NULL);
61
0
}
62
63
void
64
lydict_clean(struct dict_table *dict)
65
0
{
66
0
    struct dict_rec *dict_rec = NULL;
67
0
    struct ht_rec *rec = NULL;
68
69
0
    LY_CHECK_ARG_RET(NULL, dict, );
70
71
0
    for (uint32_t i = 0; i < dict->hash_tab->size; i++) {
72
        /* get ith record */
73
0
        rec = (struct ht_rec *)&dict->hash_tab->recs[i * dict->hash_tab->rec_size];
74
0
        if (rec->hits == 1) {
75
            /*
76
             * this should not happen, all records inserted into
77
             * dictionary are supposed to be removed using lydict_remove()
78
             * before calling lydict_clean()
79
             */
80
0
            dict_rec = (struct dict_rec *)rec->val;
81
0
            LOGWRN(NULL, "String \"%s\" not freed from the dictionary, refcount %d", dict_rec->value, dict_rec->refcount);
82
            /* if record wasn't removed before free string allocated for that record */
83
0
#ifdef NDEBUG
84
0
            free(dict_rec->value);
85
0
#endif
86
0
        }
87
0
    }
88
89
    /* free table and destroy mutex */
90
0
    lyht_free(dict->hash_tab);
91
0
    pthread_mutex_destroy(&dict->lock);
92
0
}
93
94
/*
95
 * Usage:
96
 * - init hash to 0
97
 * - repeatedly call dict_hash_multi(), provide hash from the last call
98
 * - call dict_hash_multi() with key_part = NULL to finish the hash
99
 */
100
uint32_t
101
dict_hash_multi(uint32_t hash, const char *key_part, size_t len)
102
0
{
103
0
    uint32_t i;
104
105
0
    if (key_part) {
106
0
        for (i = 0; i < len; ++i) {
107
0
            hash += key_part[i];
108
0
            hash += (hash << 10);
109
0
            hash ^= (hash >> 6);
110
0
        }
111
0
    } else {
112
0
        hash += (hash << 3);
113
0
        hash ^= (hash >> 11);
114
0
        hash += (hash << 15);
115
0
    }
116
117
0
    return hash;
118
0
}
119
120
/*
121
 * Bob Jenkin's one-at-a-time hash
122
 * http://www.burtleburtle.net/bob/hash/doobs.html
123
 *
124
 * Spooky hash is faster, but it works only for little endian architectures.
125
 */
126
uint32_t
127
dict_hash(const char *key, size_t len)
128
0
{
129
0
    uint32_t hash;
130
131
0
    hash = dict_hash_multi(0, key, len);
132
0
    return dict_hash_multi(hash, NULL, len);
133
0
}
134
135
static ly_bool
136
lydict_resize_val_eq(void *val1_p, void *val2_p, ly_bool mod, void *cb_data)
137
0
{
138
0
    LY_CHECK_ARG_RET(NULL, val1_p, val2_p, 0);
139
140
0
    const char *str1 = ((struct dict_rec *)val1_p)->value;
141
0
    const char *str2 = ((struct dict_rec *)val2_p)->value;
142
143
0
    LY_CHECK_ERR_RET(!str1, LOGARG(NULL, val1_p), 0);
144
0
    LY_CHECK_ERR_RET(!str2, LOGARG(NULL, val2_p), 0);
145
146
0
    if (mod) {
147
        /* used when inserting new values */
148
0
        if (strcmp(str1, str2) == 0) {
149
0
            return 1;
150
0
        }
151
0
    } else {
152
        /* used when finding the original value again in the resized table */
153
0
        return lydict_val_eq(val1_p, val2_p, mod, cb_data);
154
0
    }
155
156
0
    return 0;
157
0
}
158
159
API LY_ERR
160
lydict_remove(const struct ly_ctx *ctx, const char *value)
161
0
{
162
0
    LY_ERR ret = LY_SUCCESS;
163
0
    size_t len;
164
0
    uint32_t hash;
165
0
    struct dict_rec rec, *match = NULL;
166
0
    char *val_p;
167
168
0
    if (!ctx || !value) {
169
0
        return LY_SUCCESS;
170
0
    }
171
172
0
    LOGDBG(LY_LDGDICT, "removing \"%s\"", value);
173
174
0
    len = strlen(value);
175
0
    hash = dict_hash(value, len);
176
177
    /* create record for lyht_find call */
178
0
    rec.value = (char *)value;
179
0
    rec.refcount = 0;
180
181
0
    pthread_mutex_lock((pthread_mutex_t *)&ctx->dict.lock);
182
    /* set len as data for compare callback */
183
0
    lyht_set_cb_data(ctx->dict.hash_tab, (void *)&len);
184
    /* check if value is already inserted */
185
0
    ret = lyht_find(ctx->dict.hash_tab, &rec, hash, (void **)&match);
186
187
0
    if (ret == LY_SUCCESS) {
188
0
        LY_CHECK_ERR_GOTO(!match, LOGINT(ctx), finish);
189
190
        /* if value is already in dictionary, decrement reference counter */
191
0
        match->refcount--;
192
0
        if (match->refcount == 0) {
193
            /*
194
             * remove record
195
             * save pointer to stored string before lyht_remove to
196
             * free it after it is removed from hash table
197
             */
198
0
            val_p = match->value;
199
0
            ret = lyht_remove_with_resize_cb(ctx->dict.hash_tab, &rec, hash, lydict_resize_val_eq);
200
0
            free(val_p);
201
0
            LY_CHECK_ERR_GOTO(ret, LOGINT(ctx), finish);
202
0
        }
203
0
    } else if (ret == LY_ENOTFOUND) {
204
0
        LOGERR(ctx, LY_ENOTFOUND, "Value \"%s\" was not found in the dictionary.", value);
205
0
    } else {
206
0
        LOGINT(ctx);
207
0
    }
208
209
0
finish:
210
0
    pthread_mutex_unlock((pthread_mutex_t *)&ctx->dict.lock);
211
0
    return ret;
212
0
}
213
214
LY_ERR
215
dict_insert(const struct ly_ctx *ctx, char *value, size_t len, ly_bool zerocopy, const char **str_p)
216
0
{
217
0
    LY_ERR ret = LY_SUCCESS;
218
0
    struct dict_rec *match = NULL, rec;
219
0
    uint32_t hash;
220
221
0
    LOGDBG(LY_LDGDICT, "inserting \"%.*s\"", (int)len, value);
222
223
0
    hash = dict_hash(value, len);
224
    /* set len as data for compare callback */
225
0
    lyht_set_cb_data(ctx->dict.hash_tab, (void *)&len);
226
    /* create record for lyht_insert */
227
0
    rec.value = value;
228
0
    rec.refcount = 1;
229
230
0
    ret = lyht_insert_with_resize_cb(ctx->dict.hash_tab, (void *)&rec, hash, lydict_resize_val_eq, (void **)&match);
231
0
    if (ret == LY_EEXIST) {
232
0
        match->refcount++;
233
0
        if (zerocopy) {
234
0
            free(value);
235
0
        }
236
0
        ret = LY_SUCCESS;
237
0
    } else if (ret == LY_SUCCESS) {
238
0
        if (!zerocopy) {
239
            /*
240
             * allocate string for new record
241
             * record is already inserted in hash table
242
             */
243
0
            match->value = malloc(sizeof *match->value * (len + 1));
244
0
            LY_CHECK_ERR_RET(!match->value, LOGMEM(ctx), LY_EMEM);
245
0
            memcpy(match->value, value, len);
246
0
            match->value[len] = '\0';
247
0
        }
248
0
    } else {
249
        /* lyht_insert returned error */
250
0
        if (zerocopy) {
251
0
            free(value);
252
0
        }
253
0
        return ret;
254
0
    }
255
256
0
    if (str_p) {
257
0
        *str_p = match->value;
258
0
    }
259
260
0
    return ret;
261
0
}
262
263
API LY_ERR
264
lydict_insert(const struct ly_ctx *ctx, const char *value, size_t len, const char **str_p)
265
0
{
266
0
    LY_ERR result;
267
268
0
    LY_CHECK_ARG_RET(ctx, ctx, str_p, LY_EINVAL);
269
270
0
    if (!value) {
271
0
        *str_p = NULL;
272
0
        return LY_SUCCESS;
273
0
    }
274
275
0
    if (!len) {
276
0
        len = strlen(value);
277
0
    }
278
279
0
    pthread_mutex_lock((pthread_mutex_t *)&ctx->dict.lock);
280
0
    result = dict_insert(ctx, (char *)value, len, 0, str_p);
281
0
    pthread_mutex_unlock((pthread_mutex_t *)&ctx->dict.lock);
282
283
0
    return result;
284
0
}
285
286
API LY_ERR
287
lydict_insert_zc(const struct ly_ctx *ctx, char *value, const char **str_p)
288
0
{
289
0
    LY_ERR result;
290
291
0
    LY_CHECK_ARG_RET(ctx, ctx, str_p, LY_EINVAL);
292
293
0
    if (!value) {
294
0
        *str_p = NULL;
295
0
        return LY_SUCCESS;
296
0
    }
297
298
0
    pthread_mutex_lock((pthread_mutex_t *)&ctx->dict.lock);
299
0
    result = dict_insert(ctx, value, strlen(value), 1, str_p);
300
0
    pthread_mutex_unlock((pthread_mutex_t *)&ctx->dict.lock);
301
302
0
    return result;
303
0
}
304
305
struct ht_rec *
306
lyht_get_rec(unsigned char *recs, uint16_t rec_size, uint32_t idx)
307
0
{
308
0
    return (struct ht_rec *)&recs[idx * rec_size];
309
0
}
310
311
struct hash_table *
312
lyht_new(uint32_t size, uint16_t val_size, lyht_value_equal_cb val_equal, void *cb_data, uint16_t resize)
313
0
{
314
0
    struct hash_table *ht;
315
316
    /* check that 2^x == size (power of 2) */
317
0
    assert(size && !(size & (size - 1)));
318
0
    assert(val_equal && val_size);
319
0
    assert(resize == 0 || resize == 1);
320
321
0
    if (size < LYHT_MIN_SIZE) {
322
0
        size = LYHT_MIN_SIZE;
323
0
    }
324
325
0
    ht = malloc(sizeof *ht);
326
0
    LY_CHECK_ERR_RET(!ht, LOGMEM(NULL), NULL);
327
328
0
    ht->used = 0;
329
0
    ht->size = size;
330
0
    ht->invalid = 0;
331
0
    ht->val_equal = val_equal;
332
0
    ht->cb_data = cb_data;
333
0
    ht->resize = resize;
334
335
0
    ht->rec_size = (sizeof(struct ht_rec) - 1) + val_size;
336
    /* allocate the records correctly */
337
0
    ht->recs = calloc(size, ht->rec_size);
338
0
    LY_CHECK_ERR_RET(!ht->recs, free(ht); LOGMEM(NULL), NULL);
339
340
0
    return ht;
341
0
}
342
343
lyht_value_equal_cb
344
lyht_set_cb(struct hash_table *ht, lyht_value_equal_cb new_val_equal)
345
0
{
346
0
    lyht_value_equal_cb prev;
347
348
0
    prev = ht->val_equal;
349
0
    ht->val_equal = new_val_equal;
350
0
    return prev;
351
0
}
352
353
void *
354
lyht_set_cb_data(struct hash_table *ht, void *new_cb_data)
355
0
{
356
0
    void *prev;
357
358
0
    prev = ht->cb_data;
359
0
    ht->cb_data = new_cb_data;
360
0
    return prev;
361
0
}
362
363
struct hash_table *
364
lyht_dup(const struct hash_table *orig)
365
0
{
366
0
    struct hash_table *ht;
367
368
0
    LY_CHECK_ARG_RET(NULL, orig, NULL);
369
370
0
    ht = lyht_new(orig->size, orig->rec_size - (sizeof(struct ht_rec) - 1), orig->val_equal, orig->cb_data, orig->resize ? 1 : 0);
371
0
    if (!ht) {
372
0
        return NULL;
373
0
    }
374
375
0
    memcpy(ht->recs, orig->recs, orig->used * orig->rec_size);
376
0
    ht->used = orig->used;
377
0
    ht->invalid = orig->invalid;
378
0
    return ht;
379
0
}
380
381
void
382
lyht_free(struct hash_table *ht)
383
0
{
384
0
    if (ht) {
385
0
        free(ht->recs);
386
0
        free(ht);
387
0
    }
388
0
}
389
390
/**
391
 * @brief Resize a hash table.
392
 *
393
 * @param[in] ht Hash table to resize.
394
 * @param[in] operation Operation to perform. 1 to enlarge, -1 to shrink, 0 to only rehash all records.
395
 * @return LY_ERR value.
396
 */
397
static LY_ERR
398
lyht_resize(struct hash_table *ht, int operation)
399
0
{
400
0
    struct ht_rec *rec;
401
0
    unsigned char *old_recs;
402
0
    uint32_t i, old_size;
403
404
0
    old_recs = ht->recs;
405
0
    old_size = ht->size;
406
407
0
    if (operation > 0) {
408
        /* double the size */
409
0
        ht->size <<= 1;
410
0
    } else if (operation < 0) {
411
        /* half the size */
412
0
        ht->size >>= 1;
413
0
    }
414
415
0
    ht->recs = calloc(ht->size, ht->rec_size);
416
0
    LY_CHECK_ERR_RET(!ht->recs, LOGMEM(NULL); ht->recs = old_recs; ht->size = old_size, LY_EMEM);
417
418
    /* reset used and invalid, it will increase again */
419
0
    ht->used = 0;
420
0
    ht->invalid = 0;
421
422
    /* add all the old records into the new records array */
423
0
    for (i = 0; i < old_size; ++i) {
424
0
        rec = lyht_get_rec(old_recs, ht->rec_size, i);
425
0
        if (rec->hits > 0) {
426
0
            LY_ERR ret = lyht_insert(ht, rec->val, rec->hash, NULL);
427
0
            assert(!ret);
428
0
            (void)ret;
429
0
        }
430
0
    }
431
432
    /* final touches */
433
0
    free(old_recs);
434
0
    return LY_SUCCESS;
435
0
}
436
437
/**
438
 * @brief Search for the first match.
439
 *
440
 * @param[in] ht Hash table to search in.
441
 * @param[in] hash Hash to find.
442
 * @param[out] rec_p Optional found record.
443
 * @return LY_SUCCESS hash found, returned its record,
444
 * @return LY_ENOTFOUND hash not found, returned the record where it would be inserted.
445
 */
446
static LY_ERR
447
lyht_find_first(struct hash_table *ht, uint32_t hash, struct ht_rec **rec_p)
448
0
{
449
0
    struct ht_rec *rec;
450
0
    uint32_t i, idx;
451
452
0
    if (rec_p) {
453
0
        *rec_p = NULL;
454
0
    }
455
456
0
    idx = i = hash & (ht->size - 1);
457
0
    rec = lyht_get_rec(ht->recs, ht->rec_size, idx);
458
459
    /* skip through overflow and deleted records */
460
0
    while ((rec->hits != 0) && ((rec->hits == -1) || ((rec->hash & (ht->size - 1)) != idx))) {
461
0
        if ((rec->hits == -1) && rec_p && !(*rec_p)) {
462
            /* remember this record for return */
463
0
            *rec_p = rec;
464
0
        }
465
0
        i = (i + 1) % ht->size;
466
0
        if (i == idx) {
467
            /* we went through all the records (very unlikely, but possible when many records are invalid),
468
             * just return not found */
469
0
            assert(!rec_p || *rec_p);
470
0
            return LY_ENOTFOUND;
471
0
        }
472
0
        rec = lyht_get_rec(ht->recs, ht->rec_size, i);
473
0
    }
474
0
    if (rec->hits == 0) {
475
        /* we could not find the value */
476
0
        if (rec_p && !*rec_p) {
477
0
            *rec_p = rec;
478
0
        }
479
0
        return LY_ENOTFOUND;
480
0
    }
481
482
    /* we have found a record with equal (shortened) hash */
483
0
    if (rec_p) {
484
0
        *rec_p = rec;
485
0
    }
486
0
    return LY_SUCCESS;
487
0
}
488
489
/**
490
 * @brief Search for the next collision.
491
 *
492
 * @param[in] ht Hash table to search in.
493
 * @param[in,out] last Last returned collision record.
494
 * @param[in] first First collision record (hits > 1).
495
 * @return LY_SUCCESS when hash collision found, \p last points to this next collision,
496
 * @return LY_ENOTFOUND when hash collision not found, \p last points to the record where it would be inserted.
497
 */
498
static LY_ERR
499
lyht_find_collision(struct hash_table *ht, struct ht_rec **last, struct ht_rec *first)
500
0
{
501
0
    struct ht_rec *empty = NULL;
502
0
    uint32_t i, idx;
503
504
0
    assert(last && *last);
505
506
0
    idx = (*last)->hash & (ht->size - 1);
507
0
    i = (((unsigned char *)*last) - ht->recs) / ht->rec_size;
508
509
0
    do {
510
0
        i = (i + 1) % ht->size;
511
0
        *last = lyht_get_rec(ht->recs, ht->rec_size, i);
512
0
        if (*last == first) {
513
            /* we went through all the records (very unlikely, but possible when many records are invalid),
514
             * just return an invalid record */
515
0
            assert(empty);
516
0
            *last = empty;
517
0
            return LY_ENOTFOUND;
518
0
        }
519
520
0
        if (((*last)->hits == -1) && !empty) {
521
0
            empty = *last;
522
0
        }
523
0
    } while (((*last)->hits != 0) && (((*last)->hits == -1) || (((*last)->hash & (ht->size - 1)) != idx)));
524
525
0
    if ((*last)->hits > 0) {
526
        /* we found a collision */
527
0
        assert((*last)->hits == 1);
528
0
        return LY_SUCCESS;
529
0
    }
530
531
    /* no next collision found, return the record where it would be inserted */
532
0
    if (empty) {
533
0
        *last = empty;
534
0
    } /* else (*last)->hits == 0, it is already correct */
535
0
    return LY_ENOTFOUND;
536
0
}
537
538
/**
539
 * @brief Search for a record with specific value and hash.
540
 *
541
 * @param[in] ht Hash table to search in.
542
 * @param[in] val_p Pointer to the value to find.
543
 * @param[in] hash Hash to find.
544
 * @param[in] mod Whether the operation modifies the hash table (insert or remove) or not (find).
545
 * @param[out] crec_p Optional found first record.
546
 * @param[out] col Optional collision number of @p rec_p, 0 for no collision.
547
 * @param[out] rec_p Found exact matching record, may be a collision of @p crec_p.
548
 * @return LY_ENOTFOUND if no record found,
549
 * @return LY_SUCCESS if record was found.
550
 */
551
static LY_ERR
552
lyht_find_rec(struct hash_table *ht, void *val_p, uint32_t hash, ly_bool mod, struct ht_rec **crec_p, uint32_t *col,
553
        struct ht_rec **rec_p)
554
0
{
555
0
    struct ht_rec *rec, *crec;
556
0
    uint32_t i, c;
557
0
    LY_ERR r;
558
559
0
    if (crec_p) {
560
0
        *crec_p = NULL;
561
0
    }
562
0
    if (col) {
563
0
        *col = 0;
564
0
    }
565
0
    *rec_p = NULL;
566
567
0
    if (lyht_find_first(ht, hash, &rec)) {
568
        /* not found */
569
0
        return LY_ENOTFOUND;
570
0
    }
571
0
    if ((rec->hash == hash) && ht->val_equal(val_p, &rec->val, mod, ht->cb_data)) {
572
        /* even the value matches */
573
0
        if (crec_p) {
574
0
            *crec_p = rec;
575
0
        }
576
0
        if (col) {
577
0
            *col = 0;
578
0
        }
579
0
        *rec_p = rec;
580
0
        return LY_SUCCESS;
581
0
    }
582
583
    /* some collisions, we need to go through them, too */
584
0
    crec = rec;
585
0
    c = crec->hits;
586
0
    for (i = 1; i < c; ++i) {
587
0
        r = lyht_find_collision(ht, &rec, crec);
588
0
        assert(!r);
589
0
        (void)r;
590
591
        /* compare values */
592
0
        if ((rec->hash == hash) && ht->val_equal(val_p, &rec->val, mod, ht->cb_data)) {
593
0
            if (crec_p) {
594
0
                *crec_p = crec;
595
0
            }
596
0
            if (col) {
597
0
                *col = i;
598
0
            }
599
0
            *rec_p = rec;
600
0
            return LY_SUCCESS;
601
0
        }
602
0
    }
603
604
    /* not found even in collisions */
605
0
    return LY_ENOTFOUND;
606
0
}
607
608
LY_ERR
609
lyht_find(struct hash_table *ht, void *val_p, uint32_t hash, void **match_p)
610
0
{
611
0
    struct ht_rec *rec;
612
613
0
    lyht_find_rec(ht, val_p, hash, 0, NULL, NULL, &rec);
614
615
0
    if (rec && match_p) {
616
0
        *match_p = rec->val;
617
0
    }
618
0
    return rec ? LY_SUCCESS : LY_ENOTFOUND;
619
0
}
620
621
LY_ERR
622
lyht_find_next(struct hash_table *ht, void *val_p, uint32_t hash, void **match_p)
623
0
{
624
0
    struct ht_rec *rec, *crec;
625
0
    uint32_t i, c;
626
0
    LY_ERR r;
627
628
    /* found the record of the previously found value */
629
0
    if (lyht_find_rec(ht, val_p, hash, 1, &crec, &i, &rec)) {
630
        /* not found, cannot happen */
631
0
        LOGINT_RET(NULL);
632
0
    }
633
634
    /* go through collisions and find next one after the previous one */
635
0
    c = crec->hits;
636
0
    for (++i; i < c; ++i) {
637
0
        r = lyht_find_collision(ht, &rec, crec);
638
0
        assert(!r);
639
0
        (void)r;
640
641
0
        if ((rec->hash == hash) && ht->val_equal(val_p, &rec->val, 0, ht->cb_data)) {
642
            /* even the value matches */
643
0
            if (match_p) {
644
0
                *match_p = rec->val;
645
0
            }
646
0
            return LY_SUCCESS;
647
0
        }
648
0
    }
649
650
    /* the last equal value was already returned */
651
0
    return LY_ENOTFOUND;
652
0
}
653
654
LY_ERR
655
lyht_insert_with_resize_cb(struct hash_table *ht, void *val_p, uint32_t hash, lyht_value_equal_cb resize_val_equal,
656
        void **match_p)
657
0
{
658
0
    LY_ERR r, ret = LY_SUCCESS;
659
0
    struct ht_rec *rec, *crec = NULL;
660
0
    int32_t i;
661
0
    lyht_value_equal_cb old_val_equal = NULL;
662
663
0
    if (!lyht_find_first(ht, hash, &rec)) {
664
        /* we found matching shortened hash */
665
0
        if ((rec->hash == hash) && ht->val_equal(val_p, &rec->val, 1, ht->cb_data)) {
666
            /* even the value matches */
667
0
            if (match_p) {
668
0
                *match_p = (void *)&rec->val;
669
0
            }
670
0
            return LY_EEXIST;
671
0
        }
672
673
        /* some collisions, we need to go through them, too */
674
0
        crec = rec;
675
0
        for (i = 1; i < crec->hits; ++i) {
676
0
            r = lyht_find_collision(ht, &rec, crec);
677
0
            assert(!r);
678
679
            /* compare values */
680
0
            if ((rec->hash == hash) && ht->val_equal(val_p, &rec->val, 1, ht->cb_data)) {
681
0
                if (match_p) {
682
0
                    *match_p = (void *)&rec->val;
683
0
                }
684
0
                return LY_EEXIST;
685
0
            }
686
0
        }
687
688
        /* value not found, get the record where it will be inserted */
689
0
        r = lyht_find_collision(ht, &rec, crec);
690
0
        assert(r);
691
0
    }
692
693
    /* insert it into the returned record */
694
0
    assert(rec->hits < 1);
695
0
    if (rec->hits < 0) {
696
0
        --ht->invalid;
697
0
    }
698
0
    rec->hash = hash;
699
0
    rec->hits = 1;
700
0
    memcpy(&rec->val, val_p, ht->rec_size - (sizeof(struct ht_rec) - 1));
701
0
    if (match_p) {
702
0
        *match_p = (void *)&rec->val;
703
0
    }
704
705
0
    if (crec) {
706
        /* there was a collision, increase hits */
707
0
        if (crec->hits == INT32_MAX) {
708
0
            LOGINT(NULL);
709
0
        }
710
0
        ++crec->hits;
711
0
    }
712
713
    /* check size & enlarge if needed */
714
0
    ++ht->used;
715
0
    if (ht->resize) {
716
0
        r = (ht->used * LYHT_HUNDRED_PERCENTAGE) / ht->size;
717
0
        if ((ht->resize == 1) && (r >= LYHT_FIRST_SHRINK_PERCENTAGE)) {
718
            /* enable shrinking */
719
0
            ht->resize = 2;
720
0
        }
721
0
        if ((ht->resize == 2) && (r >= LYHT_ENLARGE_PERCENTAGE)) {
722
0
            if (resize_val_equal) {
723
0
                old_val_equal = lyht_set_cb(ht, resize_val_equal);
724
0
            }
725
726
            /* enlarge */
727
0
            ret = lyht_resize(ht, 1);
728
            /* if hash_table was resized, we need to find new matching value */
729
0
            if ((ret == LY_SUCCESS) && match_p) {
730
0
                lyht_find(ht, val_p, hash, match_p);
731
0
            }
732
733
0
            if (resize_val_equal) {
734
0
                lyht_set_cb(ht, old_val_equal);
735
0
            }
736
0
        }
737
0
    }
738
0
    return ret;
739
0
}
740
741
LY_ERR
742
lyht_insert(struct hash_table *ht, void *val_p, uint32_t hash, void **match_p)
743
0
{
744
0
    return lyht_insert_with_resize_cb(ht, val_p, hash, NULL, match_p);
745
0
}
746
747
LY_ERR
748
lyht_remove_with_resize_cb(struct hash_table *ht, void *val_p, uint32_t hash, lyht_value_equal_cb resize_val_equal)
749
0
{
750
0
    struct ht_rec *rec, *crec;
751
0
    int32_t i;
752
0
    ly_bool first_matched = 0;
753
0
    LY_ERR r, ret = LY_SUCCESS;
754
0
    lyht_value_equal_cb old_val_equal;
755
756
0
    LY_CHECK_ERR_RET(lyht_find_first(ht, hash, &rec), LOGARG(NULL, hash), LY_ENOTFOUND); /* hash not found */
757
758
0
    if ((rec->hash == hash) && ht->val_equal(val_p, &rec->val, 1, ht->cb_data)) {
759
        /* even the value matches */
760
0
        first_matched = 1;
761
0
    }
762
763
    /* we always need to go through collisions */
764
0
    crec = rec;
765
0
    for (i = 1; i < crec->hits; ++i) {
766
0
        r = lyht_find_collision(ht, &rec, crec);
767
0
        assert(!r);
768
769
        /* compare values */
770
0
        if (!first_matched && (rec->hash == hash) && ht->val_equal(val_p, &rec->val, 1, ht->cb_data)) {
771
0
            break;
772
0
        }
773
0
    }
774
775
0
    if (i < crec->hits) {
776
        /* one of collisions matched, reduce collision count, remove the record */
777
0
        assert(!first_matched);
778
0
        --crec->hits;
779
0
        rec->hits = -1;
780
0
    } else if (first_matched) {
781
        /* the first record matches */
782
0
        if (crec != rec) {
783
            /* ... so put the last collision in its place */
784
0
            rec->hits = crec->hits - 1;
785
0
            memcpy(crec, rec, ht->rec_size);
786
0
        }
787
0
        rec->hits = -1;
788
0
    } else {
789
        /* value not found even in collisions */
790
0
        return LY_ENOTFOUND;
791
0
    }
792
793
    /* check size & shrink if needed */
794
0
    --ht->used;
795
0
    ++ht->invalid;
796
0
    if (ht->resize == 2) {
797
0
        r = (ht->used * LYHT_HUNDRED_PERCENTAGE) / ht->size;
798
0
        if ((r < LYHT_SHRINK_PERCENTAGE) && (ht->size > LYHT_MIN_SIZE)) {
799
0
            if (resize_val_equal) {
800
0
                old_val_equal = lyht_set_cb(ht, resize_val_equal);
801
0
            }
802
803
            /* shrink */
804
0
            ret = lyht_resize(ht, -1);
805
806
0
            if (resize_val_equal) {
807
0
                lyht_set_cb(ht, old_val_equal);
808
0
            }
809
0
        }
810
0
    }
811
812
    /* rehash all records if needed */
813
0
    r = ((ht->size - ht->used - ht->invalid) * 100) / ht->size;
814
0
    if (r < LYHT_REHASH_PERCENTAGE) {
815
0
        if (resize_val_equal) {
816
0
            old_val_equal = lyht_set_cb(ht, resize_val_equal);
817
0
        }
818
819
        /* rehash */
820
0
        ret = lyht_resize(ht, 0);
821
822
0
        if (resize_val_equal) {
823
0
            lyht_set_cb(ht, old_val_equal);
824
0
        }
825
0
    }
826
827
0
    return ret;
828
0
}
829
830
LY_ERR
831
lyht_remove(struct hash_table *ht, void *val_p, uint32_t hash)
832
0
{
833
    return lyht_remove_with_resize_cb(ht, val_p, hash, NULL);
834
0
}