From 77d1abc804072f22845ac5d9f071eb883fee13d6 Mon Sep 17 00:00:00 2001
From: Daan Hoogland <daan@onecht.net>
Date: Wed, 11 Nov 2015 12:14:09 +0100
Subject: [PATCH] CLOUDSTACK-9054 use of google-optional as PoC

---
 .../com/cloud/network/NetworkModelImpl.java   |  4 ++--
 .../java/com/cloud/utils/net/NetUtils.java    | 23 +++++++++++--------
 .../com/cloud/utils/net/NetUtilsTest.java     |  9 ++++----
 3 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/server/src/com/cloud/network/NetworkModelImpl.java b/server/src/com/cloud/network/NetworkModelImpl.java
index 154e666c7a3f..bde9f49b3c23 100644
--- a/server/src/com/cloud/network/NetworkModelImpl.java
+++ b/server/src/com/cloud/network/NetworkModelImpl.java
@@ -629,8 +629,8 @@ public boolean isIP6AddressAvailableInVlan(long vlanId) {
         }
         long existedCount = _ipv6Dao.countExistedIpsInVlan(vlanId);
         BigInteger existedInt = BigInteger.valueOf(existedCount);
-        BigInteger rangeInt = NetUtils.countIp6InRange(vlan.getIp6Range());
-        return (existedInt.compareTo(rangeInt) < 0);
+        BigInteger rangeInt = NetUtils.countIp6InRange(vlan.getIp6Range()).get();// old behaviour npe on the next line
+        return (existedInt.compareTo(rangeInt) < 0);// new behaviour IllegalState Exception on the previous line
     }
 
     @Override
diff --git a/utils/src/main/java/com/cloud/utils/net/NetUtils.java b/utils/src/main/java/com/cloud/utils/net/NetUtils.java
index 883129b20ffa..7af1d95dfed6 100644
--- a/utils/src/main/java/com/cloud/utils/net/NetUtils.java
+++ b/utils/src/main/java/com/cloud/utils/net/NetUtils.java
@@ -48,6 +48,7 @@
 import com.cloud.utils.IteratorUtil;
 import com.cloud.utils.Pair;
 import com.cloud.utils.script.Script;
+import com.google.common.base.Optional;
 import com.googlecode.ipv6.IPv6Address;
 import com.googlecode.ipv6.IPv6AddressRange;
 import com.googlecode.ipv6.IPv6Network;
@@ -1263,7 +1264,11 @@ public static String getIp6FromRange(final String ip6Range) {
         final String[] ips = ip6Range.split("-");
         final String startIp = ips[0];
         final IPv6Address start = IPv6Address.fromString(startIp);
-        final BigInteger gap = countIp6InRange(ip6Range);
+        final Optional<BigInteger> gapOption = countIp6InRange(ip6Range);
+        if (! gapOption.isPresent()) {
+            return null;
+        }
+        final BigInteger gap =  gapOption.get();
         BigInteger next = new BigInteger(gap.bitLength(), s_rand);
         while (next.compareTo(gap) >= 0) {
             next = new BigInteger(gap.bitLength(), s_rand);
@@ -1302,26 +1307,26 @@ private static BigInteger convertIPv6AddressToBigInteger(final IPv6Address addr)
     }
 
     // Can cover 127 bits
-    public static BigInteger countIp6InRange(final String ip6Range) {
+    public static Optional<BigInteger> countIp6InRange(final String ip6Range) {
         if (ip6Range == null) {
-            return null;
+            return Optional.fromNullable(null);
         }
         final String[] ips = ip6Range.split("-");
-        final String startIp = ips[0];
-        String endIp = ips[0];
-        if (ips.length > 1) {
-            endIp = ips[1];
+        if(ips[0].equals("")) {
+            return Optional.fromNullable(null);
         }
+        final String startIp = ips[0];
+        final String endIp = (ips.length > 1) ? ips[1] : ips[0];
         try {
             final BigInteger startInt = convertIPv6AddressToBigInteger(IPv6Address.fromString(startIp));
             final BigInteger endInt = convertIPv6AddressToBigInteger(IPv6Address.fromString(endIp));
             if (endInt != null && startInt != null && startInt.compareTo(endInt) <= 0) {
-                return endInt.subtract(startInt).add(BigInteger.ONE);
+                return Optional.of(endInt.subtract(startInt).add(BigInteger.ONE));
             }
         } catch (final IllegalArgumentException ex) {
             s_logger.error("Failed to convert a string to an IPv6 address", ex);
         }
-        return null;
+        return Optional.fromNullable(null);
     }
 
     public static boolean isIp6InRange(final String ip6, final String ip6Range) {
diff --git a/utils/src/test/java/com/cloud/utils/net/NetUtilsTest.java b/utils/src/test/java/com/cloud/utils/net/NetUtilsTest.java
index 1ab4459d6aca..c67c34c4b689 100644
--- a/utils/src/test/java/com/cloud/utils/net/NetUtilsTest.java
+++ b/utils/src/test/java/com/cloud/utils/net/NetUtilsTest.java
@@ -38,6 +38,7 @@
 import org.apache.log4j.Logger;
 import org.junit.Test;
 
+import com.google.common.base.Optional;
 import com.googlecode.ipv6.IPv6Address;
 
 public class NetUtilsTest {
@@ -139,22 +140,22 @@ public void testGetIp6FromRange() {
 
     @Test
     public void testCountIp6InRange() {
-        assertEquals(new BigInteger("2"), NetUtils.countIp6InRange("1234:5678::1-1234:5678::2"));
+        assertEquals(Optional.of(new BigInteger("2")), NetUtils.countIp6InRange("1234:5678::1-1234:5678::2"));
     }
 
     @Test
     public void testCountIp6InRangeWithInvalidRange() {
-        assertEquals(null, NetUtils.countIp6InRange("1234:5678::2-1234:5678::0"));
+        assertEquals(Optional.absent(), NetUtils.countIp6InRange("1234:5678::2-1234:5678::0"));
     }
 
     @Test
     public void testCountIp6InRangeWithNullStart() {
-        assertEquals(null, NetUtils.countIp6InRange("-1234:5678::0"));
+        assertEquals(Optional.absent(), NetUtils.countIp6InRange("-1234:5678::0"));
     }
 
     @Test
     public void testCountIp6InRangeWithNoEnd() {
-        assertEquals(new BigInteger("1"), NetUtils.countIp6InRange("1234:5678::2"));
+        assertEquals(Optional.of(new BigInteger("1")), NetUtils.countIp6InRange("1234:5678::2"));
     }
 
     @Test