Files
libpostal/src/trie_utils.c

102 lines
2.4 KiB
C

#include "trie_utils.h"
/*
Build a trie from the sorted keys of a hashtable. Adding
keys in sorted order to a double-array trie is faster than
adding them in random order.
*/
trie_t *trie_new_from_hash(khash_t(str_uint32) *hash) {
trie_t *trie = trie_new();
const char *key;
uint32_t value;
size_t hash_size = kh_size(hash);
log_info("hash_size=%zu\n", hash_size);
string_array *hash_keys = string_array_new_size(hash_size);
kh_foreach(hash, key, value, {
if (strlen(key) == 0) continue;
string_array_push(hash_keys, (char *)key);
})
ks_introsort(str, hash_keys->n, (const char **)hash_keys->a);
khiter_t k;
for (int i = 0; i < hash_keys->n; i++) {
char *str = hash_keys->a[i];
k = kh_get(str_uint32, hash, str);
if (k == kh_end(hash)) {
log_error("Key not found\n");
string_array_destroy(hash_keys);
trie_destroy(trie);
return NULL;
}
value = kh_value(hash, k);
if (!trie_add(trie, str, value)) {
log_error("Error adding to trie\n");
string_array_destroy(hash_keys);
trie_destroy(trie);
return NULL;
}
if (i % 100000 == 0 && i > 0) {
log_info("added %d keys to trie\n", i);
}
}
string_array_destroy(hash_keys);
return trie;
}
trie_t *trie_new_from_cstring_array_sorted(cstring_array *strings) {
char *key;
uint32_t i;
int ret = 0;
uint32_t next_id = 0;
size_t n = cstring_array_num_strings(strings);
khash_t(str_uint32) *hash = kh_init(str_uint32);
kh_resize(str_uint32, hash, n);
cstring_array_foreach(strings, i, key, {
if (strlen(key) == 0) continue;
khiter_t k = kh_put(str_uint32, hash, key, &ret);
if (ret < 0) {
kh_destroy(str_uint32, hash);
return NULL;
}
kh_value(hash, k) = next_id++;
})
trie_t *trie = trie_new_from_hash(hash);
kh_destroy(str_uint32, hash);
return trie;
}
trie_t *trie_new_from_cstring_array(cstring_array *strings) {
char *key;
uint32_t i;
uint32_t next_id;
trie_t *trie = trie_new();
cstring_array_foreach(strings, i, key, {
if (strlen(key) == 0) continue;
if (!trie_add(trie, key, next_id++)) {
trie_destroy(trie);
return NULL;
}
})
return trie;
}