static int
trie_branch_in_tail(
trie_t trie, trie_idx_t sep_node,
const char *suffix, trie_data_t data)
{
trie_idx_t old_tail, old_da, s;
const char *old_suffix, *p;
/* adjust separate point in old path */
old_tail = trie_da_get_tail_index(trie->da, sep_node);
if ((old_suffix = tail_get_suffix(trie->tail, old_tail)) == NULL) {
return -1;
}
for (p = old_suffix, s = sep_node; *p == *suffix; p++, suffix++) {
trie_idx_t t = da_insert_branch(trie->da, s, *p);
if (t == TRIE_INDEX_ERROR) {
goto fail;
}
s = t;
}
old_da = da_insert_branch(trie->da, s, *p);
if (old_da == TRIE_INDEX_ERROR) {
goto fail;
}
if (*p != '\0') {
p++;
}
tail_set_suffix(trie->tail, old_tail, p);
trie_da_set_tail_index(trie->da, old_da, old_tail);
/* insert the new branch at the new separate point */
return trie_branch_in_branch(trie, s, suffix, data);
fail:
/* failed, undo previous insertions and return error */
da_prune_upto(trie->da, sep_node, s);
trie_da_set_tail_index(trie->da, sep_node, old_tail);
return -1;
}
static Bool
trie_branch_in_tail (Trie *trie,
TrieIndex sep_node,
const TrieChar *suffix,
TrieData data)
{
TrieIndex old_tail, old_da, s;
const TrieChar *old_suffix, *p;
/* adjust separate point in old path */
old_tail = trie_da_get_tail_index (trie->da, sep_node);
old_suffix = tail_get_suffix (trie->tail, old_tail);
if (!old_suffix)
return FALSE;
for (p = old_suffix, s = sep_node; *p == *suffix; p++, suffix++) {
TrieIndex t = da_insert_branch (trie->da, s, *p);
if (TRIE_INDEX_ERROR == t)
goto fail;
s = t;
}
old_da = da_insert_branch (trie->da, s, *p);
if (TRIE_INDEX_ERROR == old_da)
goto fail;
if ('\0' != *p)
++p;
tail_set_suffix (trie->tail, old_tail, p);
trie_da_set_tail_index (trie->da, old_da, old_tail);
/* insert the new branch at the new separate point */
return trie_branch_in_branch (trie, s, suffix, data);
fail:
/* failed, undo previous insertions and return error */
da_prune_upto (trie->da, sep_node, s);
trie_da_set_tail_index (trie->da, sep_node, old_tail);
return FALSE;
}
/**
* @brief Prune the single branch
*
* @param d : the double-array structure
* @param s : the dangling state to prune off
*
* Prune off a non-separate path up from the final state @a s.
* If @a s still has some children states, it does nothing. Otherwise,
* it deletes the node and all its parents which become non-separate.
*/
void
da_prune (DArray *d, TrieIndex s)
{
da_prune_upto (d, da_get_root (d), s);
}
