public Object Match_bgn_w_byte(byte b, byte[] src, int bgn_pos, int src_len) {
match_pos = bgn_pos;
ByteTrieItm_fast nxt = root.Ary_find(b);
if (nxt == null) return null; // nxt does not have b; return rv;
Object rv = null;
int cur_pos = bgn_pos + 1;
ByteTrieItm_fast cur = root;
while (true) {
if (nxt.Ary_is_empty()) {
match_pos = cur_pos;
return nxt.Val();
} // nxt is leaf; return nxt.Val() (which should be non-null)
Object nxt_val = nxt.Val();
if (nxt_val != null) {
match_pos = cur_pos;
rv = nxt_val;
} // nxt is node; cache rv (in case of false match)
if (cur_pos == src_len) return rv; // eos; exit
b = src[cur_pos];
cur = nxt;
nxt = cur.Ary_find(b);
if (nxt == null) return rv;
++cur_pos;
}
}
public Btrie_fast_mgr Add(byte[] key, Object val) {
if (val == null)
throw Err_.new_("null objects cannot be registered").Add("key", String_.new_u8(key));
int key_len = key.length;
int key_end = key_len - 1;
ByteTrieItm_fast cur = root;
for (int i = 0; i < key_len; i++) {
byte b = key[i];
ByteTrieItm_fast nxt = cur.Ary_find(b);
if (nxt == null) nxt = cur.Ary_add(b, null);
if (i == key_end) nxt.Val_set(val);
cur = nxt;
}
return this;
}
public void Del(byte[] key) {
int key_len = key.length;
ByteTrieItm_fast cur = root;
for (int i = 0; i < key_len; i++) {
byte b = key[i];
Object itm_obj = cur.Ary_find(b);
if (itm_obj == null) break; // b not found; no match; exit;
ByteTrieItm_fast itm = (ByteTrieItm_fast) itm_obj;
if (i == key_len - 1) { // last char
if (itm.Val() == null)
break; // itm does not have val; EX: trie with "abc", and "ab" deleted
if (itm.Ary_is_empty()) cur.Ary_del(b);
else itm.Val_set(null);
} else { // mid char; set itm as cur and continue
cur = itm;
}
}
}