int trie_increment(Trie *trie, char *key)
{
TrieNode **rover;
TrieNode *node;
char *p;
int c;
/* Search to see if this is already in the tree */
node = trie_find_end(trie, key);
/* Already in the tree? If so, replace the existing value and
* return success. */
if (node != NULL && node->data != TRIE_NULL) {
node->data = ++node->data;
return 1;
}
/* Search down the trie until we reach the end of string,
* creating nodes as necessary */
rover = &trie->root_node;
p = key;
for (;;) {
node = *rover;
if (node == NULL) {
/* Node does not exist, so create it */
node = (TrieNode *) calloc(1, sizeof(TrieNode));
if (node == NULL) {
/* Allocation failed. Go back and undo
* what we have done so far. */
trie_insert_rollback(trie, key);
return 0;
}
node->data = TRIE_NULL;
/* Link in to the trie */
*rover = node;
}
/* Increase the node use count */
++node->use_count;
/* Current character */
c = *p;
/* Reached the end of string? If so, we're finished. */
if (c == '\0') {
/* Set the data at the node we have reached */
node->data = ++node->data;
break;
}
/* Advance to the next node in the chain */
rover = &node->next[c];
++p;
}
return 1;
}
int trie_insert_binary(Trie *trie, unsigned char *key, int key_length,
TrieValue value)
{
TrieNode **rover;
TrieNode *node;
int p,c;
/* Cannot insert NULL values */
if (value == TRIE_NULL) {
return 0;
}
/* Search to see if this is already in the tree */
node = trie_find_end_binary(trie, key, key_length);
/* Already in the tree? If so, replace the existing value and
* return success. */
if (node != NULL && node->data != TRIE_NULL) {
node->data = value;
return 1;
}
/* Search down the trie until we reach the end of string,
* creating nodes as necessary */
rover = &trie->root_node;
p = 0;
for (;;) {
node = *rover;
if (node == NULL) {
/* Node does not exist, so create it */
node = (TrieNode *) calloc(1, sizeof(TrieNode));
if (node == NULL) {
/* Allocation failed. Go back and undo
* what we have done so far. */
trie_insert_rollback(trie, key);
return 0;
}
node->data = TRIE_NULL;
/* Link in to the trie */
*rover = node;
}
/* Increase the node use count */
++node->use_count;
/* Current character */
c = (unsigned char) key[p];
/* Reached the end of string? If so, we're finished. */
if (p == key_length) {
/* Set the data at the node we have reached */
node->data = value;
break;
}
/* Advance to the next node in the chain */
rover = &node->next[c];
++p;
}
return 1;
}
