| /* |
| * Copyright (c) 2000, 2011, Oracle and/or its affiliates. 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle 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. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.jndi.dns; |
| |
| |
| import java.util.Hashtable; |
| |
| |
| /** |
| * A NameNode represents a node in the DNS namespace. Each node |
| * has a label, which is its name relative to its parent (so the |
| * node at Sun.COM has label "Sun"). Each node has a hashtable of |
| * children indexed by their labels converted to lower-case. |
| * |
| * <p> A node may be addressed from another by giving a DnsName |
| * consisting of the sequence of labels from one node to the other. |
| * |
| * <p> Each node also has an <tt>isZoneCut</tt> flag, used to indicate |
| * if the node is a zone cut. A zone cut is a node with an NS record |
| * that is contained in one zone, but that actually belongs to a child zone. |
| * |
| * <p> All access is unsynchronized. |
| * |
| * @author Scott Seligman |
| */ |
| |
| |
| class NameNode { |
| |
| private String label; // name of this node relative to its |
| // parent, or null for root of a tree |
| private Hashtable<String,NameNode> children = null; // child nodes |
| private boolean isZoneCut = false; // true if this node is a zone cut |
| private int depth = 0; // depth in tree (0 for root) |
| |
| NameNode(String label) { |
| this.label = label; |
| } |
| |
| /* |
| * Returns a newly-allocated NameNode. Used to allocate new nodes |
| * in a tree. Should be overridden in a subclass to return an object |
| * of the subclass's type. |
| */ |
| protected NameNode newNameNode(String label) { |
| return new NameNode(label); |
| } |
| |
| /* |
| * Returns the name of this node relative to its parent, or null for |
| * the root of a tree. |
| */ |
| String getLabel() { |
| return label; |
| } |
| |
| /* |
| * Returns the depth of this node in the tree. The depth of the root |
| * is 0. |
| */ |
| int depth() { |
| return depth; |
| } |
| |
| boolean isZoneCut() { |
| return isZoneCut; |
| } |
| |
| void setZoneCut(boolean isZoneCut) { |
| this.isZoneCut = isZoneCut; |
| } |
| |
| /* |
| * Returns the children of this node, or null if there are none. |
| * The caller must not modify the Hashtable returned. |
| */ |
| Hashtable<String,NameNode> getChildren() { |
| return children; |
| } |
| |
| /* |
| * Returns the child node given the hash key (the down-cased label) |
| * for its name relative to this node, or null if there is no such |
| * child. |
| */ |
| NameNode get(String key) { |
| return (children != null) |
| ? children.get(key) |
| : null; |
| } |
| |
| /* |
| * Returns the node at the end of a path, or null if the |
| * node does not exist. |
| * The path is specified by the labels of <tt>name</tt>, beginning |
| * at index idx. |
| */ |
| NameNode get(DnsName name, int idx) { |
| NameNode node = this; |
| for (int i = idx; i < name.size() && node != null; i++) { |
| node = node.get(name.getKey(i)); |
| } |
| return node; |
| } |
| |
| /* |
| * Returns the node at the end of a path, creating it and any |
| * intermediate nodes as needed. |
| * The path is specified by the labels of <tt>name</tt>, beginning |
| * at index idx. |
| */ |
| NameNode add(DnsName name, int idx) { |
| NameNode node = this; |
| for (int i = idx; i < name.size(); i++) { |
| String label = name.get(i); |
| String key = name.getKey(i); |
| |
| NameNode child = null; |
| if (node.children == null) { |
| node.children = new Hashtable<>(); |
| } else { |
| child = node.children.get(key); |
| } |
| if (child == null) { |
| child = newNameNode(label); |
| child.depth = node.depth + 1; |
| node.children.put(key, child); |
| } |
| node = child; |
| } |
| return node; |
| } |
| } |