/*
* Copyright (c) 2017, Jaroslav Bachorik <j.bachorik@btrace.io>.
* All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Copyright owner designates
* this particular file as subject to the "Classpath" exception as provided
* by the owner in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package com.sun.btrace.util;
import java.util.HashMap;
import java.util.Map;
/**
* Simplified trie-based prefix map
*/
public class PrefixMap {
private static final class Node {
private CharSequence value;
private final Map<Character, Node> refs = new HashMap<>();
public Node() {
this.value = null;
}
public Node getReferencedNode(char ch) {
return refs.get(ch);
}
public void addReferencedNode(char ch, Node n) {
if (!refs.containsKey(ch)) {
refs.put(ch, n);
}
}
public void setValue(CharSequence val) {
this.value = val;
}
}
private final Node root = new Node();
public void add(CharSequence val) {
Node n = root;
for (int i = 0; i < val.length(); i++) {
char ch = val.charAt(i);
Node child = n.getReferencedNode(ch);
if (child == null) {
child = new Node();
n.addReferencedNode(ch, child);
}
n = child;
}
n.setValue(val);
}
public boolean contains(CharSequence val) {
Node n = root;
for (int i = 0; i < val.length(); i++) {
char ch = val.charAt(i);
Node child = n.getReferencedNode(ch);
if (child == null) {
return false;
}
if (child.value != null) {
return true;
}
n = child;
}
return false;
}
}