- /*
- * The Apache Software License, Version 1.1
- *
- *
- * Copyright (c) 1999 The Apache Software Foundation. All rights
- * reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- *
- * 3. The end-user documentation included with the redistribution,
- * if any, must include the following acknowledgment:
- * "This product includes software developed by the
- * Apache Software Foundation (http://www.apache.org/)."
- * Alternately, this acknowledgment may appear in the software itself,
- * if and wherever such third-party acknowledgments normally appear.
- *
- * 4. The names "Xalan" and "Apache Software Foundation" must
- * not be used to endorse or promote products derived from this
- * software without prior written permission. For written
- * permission, please contact apache@apache.org.
- *
- * 5. Products derived from this software may not be called "Apache",
- * nor may "Apache" appear in their name, without prior written
- * permission of the Apache Software Foundation.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
- * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- * ====================================================================
- *
- * This software consists of voluntary contributions made by many
- * individuals on behalf of the Apache Software Foundation and was
- * originally based on software copyright (c) 1999, Lotus
- * Development Corporation., http://www.lotus.com. For more
- * information on the Apache Software Foundation, please see
- * <http://www.apache.org/>.
- */
- package org.apache.xml.utils;
-
- /**
- * <meta name="usage" content="internal"/>
- * A digital search trie for 7-bit ASCII text
- * The API is a subset of java.util.Hashtable
- * The key must be a 7-bit ASCII string
- * The value may be any Java Object
- */
- public class Trie
- {
-
- /** Size of the m_nextChar array. */
- public static final int ALPHA_SIZE = 128;
-
- /** The root node of the tree. */
- Node m_Root;
-
- /**
- * Construct the trie.
- */
- public Trie()
- {
- m_Root = new Node();
- }
-
- /**
- * Put an object into the trie for lookup.
- *
- * @param key must be a 7-bit ASCII string
- * @param value any java object.
- *
- * @return The old object that matched key, or null.
- */
- public Object put(String key, Object value)
- {
-
- final int len = key.length();
- Node node = m_Root;
-
- for (int i = 0; i < len; i++)
- {
- Node nextNode = node.m_nextChar[Character.toUpperCase(key.charAt(i))];
-
- if (nextNode != null)
- {
- node = nextNode;
- }
- else
- {
- for (; i < len; i++)
- {
- Node newNode = new Node();
-
- node.m_nextChar[Character.toUpperCase(key.charAt(i))] = newNode;
- node = newNode;
- }
-
- break;
- }
- }
-
- Object ret = node.m_Value;
-
- node.m_Value = value;
-
- return ret;
- }
-
- /**
- * Get an object that matches the key.
- *
- * @param key must be a 7-bit ASCII string
- *
- * @return The object that matches the key, or null.
- */
- public Object get(String key)
- {
-
- final int len = key.length();
- Node node = m_Root;
-
- for (int i = 0; i < len; i++)
- {
- try
- {
- node = node.m_nextChar[Character.toUpperCase(key.charAt(i))];
- }
- catch (ArrayIndexOutOfBoundsException e)
- {
-
- // the key is not 7-bit ASCII so we won't find it here
- node = null;
- }
-
- if (node == null)
- return null;
- }
-
- return node.m_Value;
- }
-
- /**
- * <meta name="usage" content="internal"/>
- * The node representation for the trie.
- */
- class Node
- {
-
- /**
- * Constructor, creates a Node[ALPHA_SIZE].
- */
- Node()
- {
- m_nextChar = new Node[ALPHA_SIZE];
- m_Value = null;
- }
-
- /** The next nodes. */
- Node m_nextChar[];
-
- /** The value. */
- Object m_Value;
- }
- }