--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/jdk.naming.dns/share/classes/com/sun/jndi/dns/ZoneNode.java Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,205 @@
+/*
+ * 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.lang.ref.SoftReference;
+import java.util.Date;
+import java.util.Vector;
+
+
+/**
+ * ZoneNode extends NameNode to represent a tree of the zones in the
+ * DNS namespace, along with any intermediate nodes between zones.
+ * A ZoneNode that represents a zone may be "populated" with a
+ * NameNode tree containing the zone's contents.
+ *
+ * <p> A populated zone's contents will be flagged as having expired after
+ * the time specified by the minimum TTL value in the zone's SOA record.
+ *
+ * <p> Since zone cuts aren't directly modeled by a tree of ZoneNodes,
+ * ZoneNode.isZoneCut() always returns false.
+ *
+ * <p> The synchronization strategy is documented in DnsContext.java.
+ *
+ * <p> The zone's contents are accessed via a soft reference, so its
+ * heap space may be reclaimed when necessary. The zone may be
+ * repopulated later.
+ *
+ * @author Scott Seligman
+ */
+
+
+class ZoneNode extends NameNode {
+
+ private SoftReference<NameNode> contentsRef = null; // the zone's namespace
+ private long serialNumber = -1; // the zone data's serial number
+ private Date expiration = null; // time when the zone's data expires
+
+ ZoneNode(String label) {
+ super(label);
+ }
+
+ protected NameNode newNameNode(String label) {
+ return new ZoneNode(label);
+ }
+
+ /*
+ * Clears the contents of this node. If the node was flagged as
+ * expired, it remains so.
+ */
+ synchronized void depopulate() {
+ contentsRef = null;
+ serialNumber = -1;
+ }
+
+ /*
+ * Is this node currently populated?
+ */
+ synchronized boolean isPopulated() {
+ return (getContents() != null);
+ }
+
+ /*
+ * Returns the zone's contents, or null if the zone is not populated.
+ */
+ synchronized NameNode getContents() {
+ return (contentsRef != null)
+ ? contentsRef.get()
+ : null;
+ }
+
+ /*
+ * Has this zone's data expired?
+ */
+ synchronized boolean isExpired() {
+ return ((expiration != null) && expiration.before(new Date()));
+ }
+
+ /*
+ * Returns the deepest populated zone on the path specified by a
+ * fully-qualified domain name, or null if there is no populated
+ * zone on that path. Note that a node may be depopulated after
+ * being returned.
+ */
+ ZoneNode getDeepestPopulated(DnsName fqdn) {
+ ZoneNode znode = this;
+ ZoneNode popNode = isPopulated() ? this : null;
+ for (int i = 1; i < fqdn.size(); i++) { // "i=1" to skip root label
+ znode = (ZoneNode) znode.get(fqdn.getKey(i));
+ if (znode == null) {
+ break;
+ } else if (znode.isPopulated()) {
+ popNode = znode;
+ }
+ }
+ return popNode;
+ }
+
+ /*
+ * Populates (or repopulates) a zone given its own fully-qualified
+ * name and its resource records. Returns the zone's new contents.
+ */
+ NameNode populate(DnsName zone, ResourceRecords rrs) {
+ // assert zone.get(0).equals(""); // zone has root label
+ // assert (zone.size() == (depth() + 1)); // +1 due to root label
+
+ NameNode newContents = new NameNode(null);
+
+ for (int i = 0; i < rrs.answer.size(); i++) {
+ ResourceRecord rr = rrs.answer.elementAt(i);
+ DnsName n = rr.getName();
+
+ // Ignore resource records whose names aren't within the zone's
+ // domain. Also skip records of the zone's top node, since
+ // the zone's root NameNode is already in place.
+ if ((n.size() > zone.size()) && n.startsWith(zone)) {
+ NameNode nnode = newContents.add(n, zone.size());
+ if (rr.getType() == ResourceRecord.TYPE_NS) {
+ nnode.setZoneCut(true);
+ }
+ }
+ }
+ // The zone's SOA record is the first record in the answer section.
+ ResourceRecord soa = rrs.answer.firstElement();
+ synchronized (this) {
+ contentsRef = new SoftReference<NameNode>(newContents);
+ serialNumber = getSerialNumber(soa);
+ setExpiration(getMinimumTtl(soa));
+ return newContents;
+ }
+ }
+
+ /*
+ * Set this zone's data to expire in <tt>secsToExpiration</tt> seconds.
+ */
+ private void setExpiration(long secsToExpiration) {
+ expiration = new Date(System.currentTimeMillis() +
+ 1000 * secsToExpiration);
+ }
+
+ /*
+ * Returns an SOA record's minimum TTL field.
+ */
+ private static long getMinimumTtl(ResourceRecord soa) {
+ String rdata = (String) soa.getRdata();
+ int pos = rdata.lastIndexOf(' ') + 1;
+ return Long.parseLong(rdata.substring(pos));
+ }
+
+ /*
+ * Compares this zone's serial number with that of an SOA record.
+ * Zone must be populated.
+ * Returns a negative, zero, or positive integer as this zone's
+ * serial number is less than, equal to, or greater than the SOA
+ * record's.
+ * See ResourceRecord.compareSerialNumbers() for a description of
+ * serial number arithmetic.
+ */
+ int compareSerialNumberTo(ResourceRecord soa) {
+ // assert isPopulated();
+ return ResourceRecord.compareSerialNumbers(serialNumber,
+ getSerialNumber(soa));
+ }
+
+ /*
+ * Returns an SOA record's serial number.
+ */
+ private static long getSerialNumber(ResourceRecord soa) {
+ String rdata = (String) soa.getRdata();
+
+ // An SOA record ends with: serial refresh retry expire minimum.
+ // Set "beg" to the space before serial, and "end" to the space after.
+ // We go "backward" to avoid dealing with escaped spaces in names.
+ int beg = rdata.length();
+ int end = -1;
+ for (int i = 0; i < 5; i++) {
+ end = beg;
+ beg = rdata.lastIndexOf(' ', end - 1);
+ }
+ return Long.parseLong(rdata.substring(beg + 1, end));
+ }
+}