summaryrefslogtreecommitdiffstats
path: root/src/hash_table.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--src/hash_table.c880
1 files changed, 880 insertions, 0 deletions
diff --git a/src/hash_table.c b/src/hash_table.c
new file mode 100644
index 0000000..4f9dec3
--- /dev/null
+++ b/src/hash_table.c
@@ -0,0 +1,880 @@
+/**
+ * @file hash_table.c
+ * @author Radek Krejci <rkrejci@cesnet.cz>
+ * @brief libyang dictionary for storing strings and generic hash table
+ *
+ * Copyright (c) 2015 - 2018 CESNET, z.s.p.o.
+ *
+ * This source code is licensed under BSD 3-Clause License (the "License").
+ * You may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://opensource.org/licenses/BSD-3-Clause
+ */
+
+#include "hash_table.h"
+
+#include <assert.h>
+#include <pthread.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "common.h"
+#include "compat.h"
+#include "dict.h"
+#include "log.h"
+
+#define LYDICT_MIN_SIZE 1024
+
+/**
+ * @brief Comparison callback for dictionary's hash table
+ *
+ * Implementation of ::lyht_value_equal_cb.
+ */
+static ly_bool
+lydict_val_eq(void *val1_p, void *val2_p, ly_bool UNUSED(mod), void *cb_data)
+{
+ LY_CHECK_ARG_RET(NULL, val1_p, val2_p, cb_data, 0);
+
+ const char *str1 = ((struct dict_rec *)val1_p)->value;
+ const char *str2 = ((struct dict_rec *)val2_p)->value;
+
+ LY_CHECK_ERR_RET(!str1, LOGARG(NULL, val1_p), 0);
+ LY_CHECK_ERR_RET(!str2, LOGARG(NULL, val2_p), 0);
+
+ if (strncmp(str1, str2, *(size_t *)cb_data) == 0) {
+ return 1;
+ }
+
+ return 0;
+}
+
+void
+lydict_init(struct dict_table *dict)
+{
+ LY_CHECK_ARG_RET(NULL, dict, );
+
+ dict->hash_tab = lyht_new(LYDICT_MIN_SIZE, sizeof(struct dict_rec), lydict_val_eq, NULL, 1);
+ LY_CHECK_ERR_RET(!dict->hash_tab, LOGINT(NULL), );
+ pthread_mutex_init(&dict->lock, NULL);
+}
+
+void
+lydict_clean(struct dict_table *dict)
+{
+ struct dict_rec *dict_rec = NULL;
+ struct ht_rec *rec = NULL;
+
+ LY_CHECK_ARG_RET(NULL, dict, );
+
+ for (uint32_t i = 0; i < dict->hash_tab->size; i++) {
+ /* get ith record */
+ rec = (struct ht_rec *)&dict->hash_tab->recs[i * dict->hash_tab->rec_size];
+ if (rec->hits == 1) {
+ /*
+ * this should not happen, all records inserted into
+ * dictionary are supposed to be removed using lydict_remove()
+ * before calling lydict_clean()
+ */
+ dict_rec = (struct dict_rec *)rec->val;
+ LOGWRN(NULL, "String \"%s\" not freed from the dictionary, refcount %d", dict_rec->value, dict_rec->refcount);
+ /* if record wasn't removed before free string allocated for that record */
+#ifdef NDEBUG
+ free(dict_rec->value);
+#endif
+ }
+ }
+
+ /* free table and destroy mutex */
+ lyht_free(dict->hash_tab);
+ pthread_mutex_destroy(&dict->lock);
+}
+
+/*
+ * Usage:
+ * - init hash to 0
+ * - repeatedly call dict_hash_multi(), provide hash from the last call
+ * - call dict_hash_multi() with key_part = NULL to finish the hash
+ */
+uint32_t
+dict_hash_multi(uint32_t hash, const char *key_part, size_t len)
+{
+ uint32_t i;
+
+ if (key_part && len) {
+ for (i = 0; i < len; ++i) {
+ hash += key_part[i];
+ hash += (hash << 10);
+ hash ^= (hash >> 6);
+ }
+ } else {
+ hash += (hash << 3);
+ hash ^= (hash >> 11);
+ hash += (hash << 15);
+ }
+
+ return hash;
+}
+
+/*
+ * Bob Jenkin's one-at-a-time hash
+ * http://www.burtleburtle.net/bob/hash/doobs.html
+ *
+ * Spooky hash is faster, but it works only for little endian architectures.
+ */
+uint32_t
+dict_hash(const char *key, size_t len)
+{
+ uint32_t hash;
+
+ hash = dict_hash_multi(0, key, len);
+ return dict_hash_multi(hash, NULL, len);
+}
+
+static ly_bool
+lydict_resize_val_eq(void *val1_p, void *val2_p, ly_bool mod, void *cb_data)
+{
+ LY_CHECK_ARG_RET(NULL, val1_p, val2_p, 0);
+
+ const char *str1 = ((struct dict_rec *)val1_p)->value;
+ const char *str2 = ((struct dict_rec *)val2_p)->value;
+
+ LY_CHECK_ERR_RET(!str1, LOGARG(NULL, val1_p), 0);
+ LY_CHECK_ERR_RET(!str2, LOGARG(NULL, val2_p), 0);
+
+ if (mod) {
+ /* used when inserting new values */
+ if (strcmp(str1, str2) == 0) {
+ return 1;
+ }
+ } else {
+ /* used when finding the original value again in the resized table */
+ return lydict_val_eq(val1_p, val2_p, mod, cb_data);
+ }
+
+ return 0;
+}
+
+LIBYANG_API_DEF LY_ERR
+lydict_remove(const struct ly_ctx *ctx, const char *value)
+{
+ LY_ERR ret = LY_SUCCESS;
+ size_t len;
+ uint32_t hash;
+ struct dict_rec rec, *match = NULL;
+ char *val_p;
+
+ if (!ctx || !value) {
+ return LY_SUCCESS;
+ }
+
+ LOGDBG(LY_LDGDICT, "removing \"%s\"", value);
+
+ len = strlen(value);
+ hash = dict_hash(value, len);
+
+ /* create record for lyht_find call */
+ rec.value = (char *)value;
+ rec.refcount = 0;
+
+ pthread_mutex_lock((pthread_mutex_t *)&ctx->dict.lock);
+ /* set len as data for compare callback */
+ lyht_set_cb_data(ctx->dict.hash_tab, (void *)&len);
+ /* check if value is already inserted */
+ ret = lyht_find(ctx->dict.hash_tab, &rec, hash, (void **)&match);
+
+ if (ret == LY_SUCCESS) {
+ LY_CHECK_ERR_GOTO(!match, LOGINT(ctx), finish);
+
+ /* if value is already in dictionary, decrement reference counter */
+ match->refcount--;
+ if (match->refcount == 0) {
+ /*
+ * remove record
+ * save pointer to stored string before lyht_remove to
+ * free it after it is removed from hash table
+ */
+ val_p = match->value;
+ ret = lyht_remove_with_resize_cb(ctx->dict.hash_tab, &rec, hash, lydict_resize_val_eq);
+ free(val_p);
+ LY_CHECK_ERR_GOTO(ret, LOGINT(ctx), finish);
+ }
+ } else if (ret == LY_ENOTFOUND) {
+ LOGERR(ctx, LY_ENOTFOUND, "Value \"%s\" was not found in the dictionary.", value);
+ } else {
+ LOGINT(ctx);
+ }
+
+finish:
+ pthread_mutex_unlock((pthread_mutex_t *)&ctx->dict.lock);
+ return ret;
+}
+
+LY_ERR
+dict_insert(const struct ly_ctx *ctx, char *value, size_t len, ly_bool zerocopy, const char **str_p)
+{
+ LY_ERR ret = LY_SUCCESS;
+ struct dict_rec *match = NULL, rec;
+ uint32_t hash;
+
+ LOGDBG(LY_LDGDICT, "inserting \"%.*s\"", (int)len, value);
+
+ hash = dict_hash(value, len);
+ /* set len as data for compare callback */
+ lyht_set_cb_data(ctx->dict.hash_tab, (void *)&len);
+ /* create record for lyht_insert */
+ rec.value = value;
+ rec.refcount = 1;
+
+ ret = lyht_insert_with_resize_cb(ctx->dict.hash_tab, (void *)&rec, hash, lydict_resize_val_eq, (void **)&match);
+ if (ret == LY_EEXIST) {
+ match->refcount++;
+ if (zerocopy) {
+ free(value);
+ }
+ ret = LY_SUCCESS;
+ } else if (ret == LY_SUCCESS) {
+ if (!zerocopy) {
+ /*
+ * allocate string for new record
+ * record is already inserted in hash table
+ */
+ match->value = malloc(sizeof *match->value * (len + 1));
+ LY_CHECK_ERR_RET(!match->value, LOGMEM(ctx), LY_EMEM);
+ if (len) {
+ memcpy(match->value, value, len);
+ }
+ match->value[len] = '\0';
+ }
+ } else {
+ /* lyht_insert returned error */
+ if (zerocopy) {
+ free(value);
+ }
+ return ret;
+ }
+
+ if (str_p) {
+ *str_p = match->value;
+ }
+
+ return ret;
+}
+
+LIBYANG_API_DEF LY_ERR
+lydict_insert(const struct ly_ctx *ctx, const char *value, size_t len, const char **str_p)
+{
+ LY_ERR result;
+
+ LY_CHECK_ARG_RET(ctx, ctx, str_p, LY_EINVAL);
+
+ if (!value) {
+ *str_p = NULL;
+ return LY_SUCCESS;
+ }
+
+ if (!len) {
+ len = strlen(value);
+ }
+
+ pthread_mutex_lock((pthread_mutex_t *)&ctx->dict.lock);
+ result = dict_insert(ctx, (char *)value, len, 0, str_p);
+ pthread_mutex_unlock((pthread_mutex_t *)&ctx->dict.lock);
+
+ return result;
+}
+
+LIBYANG_API_DEF LY_ERR
+lydict_insert_zc(const struct ly_ctx *ctx, char *value, const char **str_p)
+{
+ LY_ERR result;
+
+ LY_CHECK_ARG_RET(ctx, ctx, str_p, LY_EINVAL);
+
+ if (!value) {
+ *str_p = NULL;
+ return LY_SUCCESS;
+ }
+
+ pthread_mutex_lock((pthread_mutex_t *)&ctx->dict.lock);
+ result = dict_insert(ctx, value, strlen(value), 1, str_p);
+ pthread_mutex_unlock((pthread_mutex_t *)&ctx->dict.lock);
+
+ return result;
+}
+
+struct ht_rec *
+lyht_get_rec(unsigned char *recs, uint16_t rec_size, uint32_t idx)
+{
+ return (struct ht_rec *)&recs[idx * rec_size];
+}
+
+struct hash_table *
+lyht_new(uint32_t size, uint16_t val_size, lyht_value_equal_cb val_equal, void *cb_data, uint16_t resize)
+{
+ struct hash_table *ht;
+
+ /* check that 2^x == size (power of 2) */
+ assert(size && !(size & (size - 1)));
+ assert(val_equal && val_size);
+ assert(resize == 0 || resize == 1);
+
+ if (size < LYHT_MIN_SIZE) {
+ size = LYHT_MIN_SIZE;
+ }
+
+ ht = malloc(sizeof *ht);
+ LY_CHECK_ERR_RET(!ht, LOGMEM(NULL), NULL);
+
+ ht->used = 0;
+ ht->size = size;
+ ht->invalid = 0;
+ ht->val_equal = val_equal;
+ ht->cb_data = cb_data;
+ ht->resize = resize;
+
+ ht->rec_size = (sizeof(struct ht_rec) - 1) + val_size;
+ /* allocate the records correctly */
+ ht->recs = calloc(size, ht->rec_size);
+ LY_CHECK_ERR_RET(!ht->recs, free(ht); LOGMEM(NULL), NULL);
+
+ return ht;
+}
+
+lyht_value_equal_cb
+lyht_set_cb(struct hash_table *ht, lyht_value_equal_cb new_val_equal)
+{
+ lyht_value_equal_cb prev;
+
+ prev = ht->val_equal;
+ ht->val_equal = new_val_equal;
+ return prev;
+}
+
+void *
+lyht_set_cb_data(struct hash_table *ht, void *new_cb_data)
+{
+ void *prev;
+
+ prev = ht->cb_data;
+ ht->cb_data = new_cb_data;
+ return prev;
+}
+
+struct hash_table *
+lyht_dup(const struct hash_table *orig)
+{
+ struct hash_table *ht;
+
+ LY_CHECK_ARG_RET(NULL, orig, NULL);
+
+ ht = lyht_new(orig->size, orig->rec_size - (sizeof(struct ht_rec) - 1), orig->val_equal, orig->cb_data, orig->resize ? 1 : 0);
+ if (!ht) {
+ return NULL;
+ }
+
+ memcpy(ht->recs, orig->recs, (size_t)orig->used * (size_t)orig->rec_size);
+ ht->used = orig->used;
+ ht->invalid = orig->invalid;
+ return ht;
+}
+
+void
+lyht_free(struct hash_table *ht)
+{
+ if (ht) {
+ free(ht->recs);
+ free(ht);
+ }
+}
+
+/**
+ * @brief Resize a hash table.
+ *
+ * @param[in] ht Hash table to resize.
+ * @param[in] operation Operation to perform. 1 to enlarge, -1 to shrink, 0 to only rehash all records.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyht_resize(struct hash_table *ht, int operation)
+{
+ struct ht_rec *rec;
+ unsigned char *old_recs;
+ uint32_t i, old_size;
+
+ old_recs = ht->recs;
+ old_size = ht->size;
+
+ if (operation > 0) {
+ /* double the size */
+ ht->size <<= 1;
+ } else if (operation < 0) {
+ /* half the size */
+ ht->size >>= 1;
+ }
+
+ ht->recs = calloc(ht->size, ht->rec_size);
+ LY_CHECK_ERR_RET(!ht->recs, LOGMEM(NULL); ht->recs = old_recs; ht->size = old_size, LY_EMEM);
+
+ /* reset used and invalid, it will increase again */
+ ht->used = 0;
+ ht->invalid = 0;
+
+ /* add all the old records into the new records array */
+ for (i = 0; i < old_size; ++i) {
+ rec = lyht_get_rec(old_recs, ht->rec_size, i);
+ if (rec->hits > 0) {
+ LY_ERR ret = lyht_insert(ht, rec->val, rec->hash, NULL);
+
+ assert(!ret);
+ (void)ret;
+ }
+ }
+
+ /* final touches */
+ free(old_recs);
+ return LY_SUCCESS;
+}
+
+/**
+ * @brief Search for the first match.
+ *
+ * @param[in] ht Hash table to search in.
+ * @param[in] hash Hash to find.
+ * @param[out] rec_p Optional found record.
+ * @return LY_SUCCESS hash found, returned its record,
+ * @return LY_ENOTFOUND hash not found, returned the record where it would be inserted.
+ */
+static LY_ERR
+lyht_find_first(struct hash_table *ht, uint32_t hash, struct ht_rec **rec_p)
+{
+ struct ht_rec *rec;
+ uint32_t i, idx;
+
+ if (rec_p) {
+ *rec_p = NULL;
+ }
+
+ idx = i = hash & (ht->size - 1);
+ rec = lyht_get_rec(ht->recs, ht->rec_size, idx);
+
+ /* skip through overflow and deleted records */
+ while ((rec->hits != 0) && ((rec->hits == -1) || ((rec->hash & (ht->size - 1)) != idx))) {
+ if ((rec->hits == -1) && rec_p && !(*rec_p)) {
+ /* remember this record for return */
+ *rec_p = rec;
+ }
+ i = (i + 1) % ht->size;
+ if (i == idx) {
+ /* we went through all the records (very unlikely, but possible when many records are invalid),
+ * just return not found */
+ assert(!rec_p || *rec_p);
+ return LY_ENOTFOUND;
+ }
+ rec = lyht_get_rec(ht->recs, ht->rec_size, i);
+ }
+ if (rec->hits == 0) {
+ /* we could not find the value */
+ if (rec_p && !*rec_p) {
+ *rec_p = rec;
+ }
+ return LY_ENOTFOUND;
+ }
+
+ /* we have found a record with equal (shortened) hash */
+ if (rec_p) {
+ *rec_p = rec;
+ }
+ return LY_SUCCESS;
+}
+
+/**
+ * @brief Search for the next collision.
+ *
+ * @param[in] ht Hash table to search in.
+ * @param[in,out] last Last returned collision record.
+ * @param[in] first First collision record (hits > 1).
+ * @return LY_SUCCESS when hash collision found, \p last points to this next collision,
+ * @return LY_ENOTFOUND when hash collision not found, \p last points to the record where it would be inserted.
+ */
+static LY_ERR
+lyht_find_collision(struct hash_table *ht, struct ht_rec **last, struct ht_rec *first)
+{
+ struct ht_rec *empty = NULL;
+ uint32_t i, idx;
+
+ assert(last && *last);
+
+ idx = (*last)->hash & (ht->size - 1);
+ i = (((unsigned char *)*last) - ht->recs) / ht->rec_size;
+
+ do {
+ i = (i + 1) % ht->size;
+ *last = lyht_get_rec(ht->recs, ht->rec_size, i);
+ if (*last == first) {
+ /* we went through all the records (very unlikely, but possible when many records are invalid),
+ * just return an invalid record */
+ assert(empty);
+ *last = empty;
+ return LY_ENOTFOUND;
+ }
+
+ if (((*last)->hits == -1) && !empty) {
+ empty = *last;
+ }
+ } while (((*last)->hits != 0) && (((*last)->hits == -1) || (((*last)->hash & (ht->size - 1)) != idx)));
+
+ if ((*last)->hits > 0) {
+ /* we found a collision */
+ assert((*last)->hits == 1);
+ return LY_SUCCESS;
+ }
+
+ /* no next collision found, return the record where it would be inserted */
+ if (empty) {
+ *last = empty;
+ } /* else (*last)->hits == 0, it is already correct */
+ return LY_ENOTFOUND;
+}
+
+/**
+ * @brief Search for a record with specific value and hash.
+ *
+ * @param[in] ht Hash table to search in.
+ * @param[in] val_p Pointer to the value to find.
+ * @param[in] hash Hash to find.
+ * @param[in] mod Whether the operation modifies the hash table (insert or remove) or not (find).
+ * @param[out] crec_p Optional found first record.
+ * @param[out] col Optional collision number of @p rec_p, 0 for no collision.
+ * @param[out] rec_p Found exact matching record, may be a collision of @p crec_p.
+ * @return LY_ENOTFOUND if no record found,
+ * @return LY_SUCCESS if record was found.
+ */
+static LY_ERR
+lyht_find_rec(struct hash_table *ht, void *val_p, uint32_t hash, ly_bool mod, struct ht_rec **crec_p, uint32_t *col,
+ struct ht_rec **rec_p)
+{
+ struct ht_rec *rec, *crec;
+ uint32_t i, c;
+ LY_ERR r;
+
+ if (crec_p) {
+ *crec_p = NULL;
+ }
+ if (col) {
+ *col = 0;
+ }
+ *rec_p = NULL;
+
+ if (lyht_find_first(ht, hash, &rec)) {
+ /* not found */
+ return LY_ENOTFOUND;
+ }
+ if ((rec->hash == hash) && ht->val_equal(val_p, &rec->val, mod, ht->cb_data)) {
+ /* even the value matches */
+ if (crec_p) {
+ *crec_p = rec;
+ }
+ if (col) {
+ *col = 0;
+ }
+ *rec_p = rec;
+ return LY_SUCCESS;
+ }
+
+ /* some collisions, we need to go through them, too */
+ crec = rec;
+ c = crec->hits;
+ for (i = 1; i < c; ++i) {
+ r = lyht_find_collision(ht, &rec, crec);
+ assert(!r);
+ (void)r;
+
+ /* compare values */
+ if ((rec->hash == hash) && ht->val_equal(val_p, &rec->val, mod, ht->cb_data)) {
+ if (crec_p) {
+ *crec_p = crec;
+ }
+ if (col) {
+ *col = i;
+ }
+ *rec_p = rec;
+ return LY_SUCCESS;
+ }
+ }
+
+ /* not found even in collisions */
+ return LY_ENOTFOUND;
+}
+
+LY_ERR
+lyht_find(struct hash_table *ht, void *val_p, uint32_t hash, void **match_p)
+{
+ struct ht_rec *rec;
+
+ lyht_find_rec(ht, val_p, hash, 0, NULL, NULL, &rec);
+
+ if (rec && match_p) {
+ *match_p = rec->val;
+ }
+ return rec ? LY_SUCCESS : LY_ENOTFOUND;
+}
+
+LY_ERR
+lyht_find_next_with_collision_cb(struct hash_table *ht, void *val_p, uint32_t hash,
+ lyht_value_equal_cb collision_val_equal, void **match_p)
+{
+ struct ht_rec *rec, *crec;
+ uint32_t i, c;
+ LY_ERR r;
+
+ /* find the record of the previously found value */
+ if (lyht_find_rec(ht, val_p, hash, 1, &crec, &i, &rec)) {
+ /* not found, cannot happen */
+ LOGINT_RET(NULL);
+ }
+
+ /* go through collisions and find the next one after the previous one */
+ c = crec->hits;
+ for (++i; i < c; ++i) {
+ r = lyht_find_collision(ht, &rec, crec);
+ assert(!r);
+ (void)r;
+
+ if (rec->hash != hash) {
+ continue;
+ }
+
+ if (collision_val_equal) {
+ if (collision_val_equal(val_p, &rec->val, 0, ht->cb_data)) {
+ /* even the value matches */
+ if (match_p) {
+ *match_p = rec->val;
+ }
+ return LY_SUCCESS;
+ }
+ } else if (ht->val_equal(val_p, &rec->val, 0, ht->cb_data)) {
+ /* even the value matches */
+ if (match_p) {
+ *match_p = rec->val;
+ }
+ return LY_SUCCESS;
+ }
+ }
+
+ /* the last equal value was already returned */
+ return LY_ENOTFOUND;
+}
+
+LY_ERR
+lyht_find_next(struct hash_table *ht, void *val_p, uint32_t hash, void **match_p)
+{
+ return lyht_find_next_with_collision_cb(ht, val_p, hash, NULL, match_p);
+}
+
+LY_ERR
+lyht_insert_with_resize_cb(struct hash_table *ht, void *val_p, uint32_t hash, lyht_value_equal_cb resize_val_equal,
+ void **match_p)
+{
+ LY_ERR r, ret = LY_SUCCESS;
+ struct ht_rec *rec, *crec = NULL;
+ int32_t i;
+ lyht_value_equal_cb old_val_equal = NULL;
+
+ if (!lyht_find_first(ht, hash, &rec)) {
+ /* we found matching shortened hash */
+ if ((rec->hash == hash) && ht->val_equal(val_p, &rec->val, 1, ht->cb_data)) {
+ /* even the value matches */
+ if (match_p) {
+ *match_p = (void *)&rec->val;
+ }
+ return LY_EEXIST;
+ }
+
+ /* some collisions, we need to go through them, too */
+ crec = rec;
+ for (i = 1; i < crec->hits; ++i) {
+ r = lyht_find_collision(ht, &rec, crec);
+ assert(!r);
+
+ /* compare values */
+ if ((rec->hash == hash) && ht->val_equal(val_p, &rec->val, 1, ht->cb_data)) {
+ if (match_p) {
+ *match_p = (void *)&rec->val;
+ }
+ return LY_EEXIST;
+ }
+ }
+
+ /* value not found, get the record where it will be inserted */
+ r = lyht_find_collision(ht, &rec, crec);
+ assert(r);
+ }
+
+ /* insert it into the returned record */
+ assert(rec->hits < 1);
+ if (rec->hits < 0) {
+ --ht->invalid;
+ }
+ rec->hash = hash;
+ rec->hits = 1;
+ memcpy(&rec->val, val_p, ht->rec_size - (sizeof(struct ht_rec) - 1));
+ if (match_p) {
+ *match_p = (void *)&rec->val;
+ }
+
+ if (crec) {
+ /* there was a collision, increase hits */
+ if (crec->hits == INT32_MAX) {
+ LOGINT(NULL);
+ }
+ ++crec->hits;
+ }
+
+ /* check size & enlarge if needed */
+ ++ht->used;
+ if (ht->resize) {
+ r = (ht->used * LYHT_HUNDRED_PERCENTAGE) / ht->size;
+ if ((ht->resize == 1) && (r >= LYHT_FIRST_SHRINK_PERCENTAGE)) {
+ /* enable shrinking */
+ ht->resize = 2;
+ }
+ if ((ht->resize == 2) && (r >= LYHT_ENLARGE_PERCENTAGE)) {
+ if (resize_val_equal) {
+ old_val_equal = lyht_set_cb(ht, resize_val_equal);
+ }
+
+ /* enlarge */
+ ret = lyht_resize(ht, 1);
+ /* if hash_table was resized, we need to find new matching value */
+ if ((ret == LY_SUCCESS) && match_p) {
+ lyht_find(ht, val_p, hash, match_p);
+ }
+
+ if (resize_val_equal) {
+ lyht_set_cb(ht, old_val_equal);
+ }
+ }
+ }
+ return ret;
+}
+
+LY_ERR
+lyht_insert(struct hash_table *ht, void *val_p, uint32_t hash, void **match_p)
+{
+ return lyht_insert_with_resize_cb(ht, val_p, hash, NULL, match_p);
+}
+
+LY_ERR
+lyht_remove_with_resize_cb(struct hash_table *ht, void *val_p, uint32_t hash, lyht_value_equal_cb resize_val_equal)
+{
+ struct ht_rec *rec, *crec;
+ int32_t i;
+ ly_bool first_matched = 0;
+ LY_ERR r, ret = LY_SUCCESS;
+ lyht_value_equal_cb old_val_equal;
+
+ LY_CHECK_ERR_RET(lyht_find_first(ht, hash, &rec), LOGARG(NULL, hash), LY_ENOTFOUND); /* hash not found */
+
+ if ((rec->hash == hash) && ht->val_equal(val_p, &rec->val, 1, ht->cb_data)) {
+ /* even the value matches */
+ first_matched = 1;
+ }
+
+ /* we always need to go through collisions */
+ crec = rec;
+ for (i = 1; i < crec->hits; ++i) {
+ r = lyht_find_collision(ht, &rec, crec);
+ assert(!r);
+
+ /* compare values */
+ if (!first_matched && (rec->hash == hash) && ht->val_equal(val_p, &rec->val, 1, ht->cb_data)) {
+ break;
+ }
+ }
+
+ if (i < crec->hits) {
+ /* one of collisions matched, reduce collision count, remove the record */
+ assert(!first_matched);
+ --crec->hits;
+ rec->hits = -1;
+ } else if (first_matched) {
+ /* the first record matches */
+ if (crec != rec) {
+ /* ... so put the last collision in its place */
+ rec->hits = crec->hits - 1;
+ memcpy(crec, rec, ht->rec_size);
+ }
+ rec->hits = -1;
+ } else {
+ /* value not found even in collisions */
+ return LY_ENOTFOUND;
+ }
+
+ /* check size & shrink if needed */
+ --ht->used;
+ ++ht->invalid;
+ if (ht->resize == 2) {
+ r = (ht->used * LYHT_HUNDRED_PERCENTAGE) / ht->size;
+ if ((r < LYHT_SHRINK_PERCENTAGE) && (ht->size > LYHT_MIN_SIZE)) {
+ if (resize_val_equal) {
+ old_val_equal = lyht_set_cb(ht, resize_val_equal);
+ }
+
+ /* shrink */
+ ret = lyht_resize(ht, -1);
+
+ if (resize_val_equal) {
+ lyht_set_cb(ht, old_val_equal);
+ }
+ }
+ }
+
+ /* rehash all records if needed */
+ r = ((ht->size - ht->used - ht->invalid) * 100) / ht->size;
+ if (r < LYHT_REHASH_PERCENTAGE) {
+ if (resize_val_equal) {
+ old_val_equal = lyht_set_cb(ht, resize_val_equal);
+ }
+
+ /* rehash */
+ ret = lyht_resize(ht, 0);
+
+ if (resize_val_equal) {
+ lyht_set_cb(ht, old_val_equal);
+ }
+ }
+
+ return ret;
+}
+
+LY_ERR
+lyht_remove(struct hash_table *ht, void *val_p, uint32_t hash)
+{
+ return lyht_remove_with_resize_cb(ht, val_p, hash, NULL);
+}
+
+uint32_t
+lyht_get_fixed_size(uint32_t item_count)
+{
+ uint32_t i, size = 0;
+
+ /* detect number of upper zero bits in the items' counter value ... */
+ for (i = (sizeof item_count * CHAR_BIT) - 1; i > 0; i--) {
+ size = item_count << i;
+ size = size >> i;
+ if (size == item_count) {
+ break;
+ }
+ }
+ assert(i);
+
+ /* ... and then we convert it to the position of the highest non-zero bit ... */
+ i = (sizeof item_count * CHAR_BIT) - i;
+
+ /* ... and by using it to shift 1 to the left we get the closest sufficient hash table size */
+ size = 1 << i;
+
+ return size;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-10 01:40:01 +0000