commit f9377607fbfd88427e5a020793cbf2f1d1b6849d
author Ronald Li <ronald.li@bigswitch.com> Mon Jul 07 18:13:29 2014 -0700
committer Ronald Li <ronald.li@bigswitch.com> Mon Jul 07 18:13:29 2014 -0700
tree e7a93b668832b5f050c114a3752d2191335701ad
parent bbf0194602c68106528afb80cde1f684715ee551

Use IPv6 subnet mask calculation as suggested by @andi-bigswitch

Reference:
https://github.com/ronaldchl/loxigen/commit/fea1789f36d0edba5cf991ff0a953e9ef445f078#commitcomment-6923088

java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/IPv6Address.java

diff --git a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/IPv6Address.java b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/IPv6Address.java
index dcbd4a1..29a3726 100644
--- a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/IPv6Address.java
+++ b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/IPv6Address.java
@@ -1,6 +1,5 @@
 package org.projectfloodlight.openflow.types;
 
-import java.math.BigInteger;
 import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.util.Arrays;
@@ -322,23 +321,11 @@
         } else if (cidrMaskLength == 0) {
             return IPv6Address.FULL_MASK;
         } else {
-            BigInteger mask
-                    = BigInteger.ONE.negate().shiftLeft(128 - cidrMaskLength);
-            byte[] maskBytesTemp = mask.toByteArray();
-            byte[] maskBytes;
-            if (maskBytesTemp.length < 16) {
-                maskBytes = new byte[16];
-                System.arraycopy(maskBytesTemp, 0,
-                        maskBytes, 16 - maskBytesTemp.length,
-                        maskBytesTemp.length);
-                Arrays.fill(maskBytes, 0, 16 - maskBytesTemp.length, (byte)(0xFF));
-            } else if (maskBytesTemp.length > 16) {
-                maskBytes = new byte[16];
-                System.arraycopy(maskBytesTemp, 0, maskBytes, 0, maskBytes.length);
-            } else {
-                maskBytes = maskBytesTemp;
-            }
-            return IPv6Address.of(maskBytes);
+            int shift1 = Math.min(cidrMaskLength, 64);
+            long raw1 = shift1 == 0 ? 0 : (long) -1 << (64 - shift1);
+            int shift2 = Math.max(cidrMaskLength - 64, 0);
+            long raw2 = shift2 == 0 ? 0 : (long) -1 << (64 - shift2);
+            return IPv6Address.of(raw1, raw2);
         }
     }