From 484c660cf9b34458e3fe908ea158c7aeb188bfb4 Mon Sep 17 00:00:00 2001
From: Emil Ivov <emcho@jitsi.org>
Date: Wed, 24 Nov 2010 21:27:27 +0000
Subject: [PATCH] Work in progress on the implementation of parallel DNS
 queries.

---
 .../communicator/util/dns/ParallelLookup.java | 108 ++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 src/net/java/sip/communicator/util/dns/ParallelLookup.java

diff --git a/src/net/java/sip/communicator/util/dns/ParallelLookup.java b/src/net/java/sip/communicator/util/dns/ParallelLookup.java
new file mode 100644
index 000000000..9b1d2cfca
--- /dev/null
+++ b/src/net/java/sip/communicator/util/dns/ParallelLookup.java
@@ -0,0 +1,108 @@
+/*
+ * SIP Communicator, the OpenSource Java VoIP and Instant Messaging client.
+ *
+ * Distributable under LGPL license.
+ * See terms of license at gnu.org.
+ */
+package net.java.sip.communicator.util.dns;
+
+import java.text.*;
+
+import net.java.sip.communicator.util.*;
+
+import org.xbill.DNS.*;
+
+/**
+ *
+ *
+ * @author Emil Ivov
+ */
+public class ParallelLookup
+{
+    /**
+     * The <tt>Logger</tt> used by the <tt>ParallelLookup</tt>
+     * class and its instances for logging output.
+     */
+    private static final Logger logger = Logger.getLogger(ParallelLookup.class
+                    .getName());
+
+    /**
+     *
+     *
+     * @param domain
+     * @return
+     */
+    public Record[] lookup(String domain)
+
+        throws ParseException
+    {
+        Record[] records = null;
+        Lookup lookup;
+        try
+        {
+            lookup = new Lookup(domain, Type.SRV);
+
+            new LookupThread(lookup).start();
+        }
+        catch (TextParseException tpe)
+        {
+            logger.error("Failed to parse domain="+domain, tpe);
+            throw new ParseException(tpe.getMessage(), 0);
+        }
+
+        return records;
+    }
+
+    /**
+     * The {@link Thread} that executes a single {@link Lookup} in a
+     * non-blocking way.
+     */
+    private final class LookupThread extends Thread
+    {
+        Lookup lookup;
+
+        boolean done = false;
+
+        public LookupThread(Lookup lookup)
+        {
+            this.lookup = lookup;
+        }
+
+        /**
+         *
+         */
+        public void run()
+        {
+            lookup.run();
+
+            synchronized(this)
+            {
+                done = true;
+                notify();
+            }
+        }
+
+        public Record[] lookUpAndWaitFor(long patience)
+        {
+            this.start();
+
+            synchronized(this)
+            {
+                if ( !done )
+                {
+                    try
+                    {
+                        wait(patience);
+                    }
+                    catch(InterruptedException iexc)
+                    {
+                    }
+                }
+
+                done = true;
+            }
+
+            return lookup.getAnswers();
+        }
+    }
+}