initial import
Change-Id: Ief25aef0066ea96bd2c329ccef974c072b3a5a73
diff --git a/of/lib/src/main/java/org/projectfloodlight/openflow/types/HashValueUtils.java b/of/lib/src/main/java/org/projectfloodlight/openflow/types/HashValueUtils.java
new file mode 100644
index 0000000..15f8a9b
--- /dev/null
+++ b/of/lib/src/main/java/org/projectfloodlight/openflow/types/HashValueUtils.java
@@ -0,0 +1,29 @@
+package org.projectfloodlight.openflow.types;
+
+import com.google.common.base.Preconditions;
+
+public class HashValueUtils {
+ private HashValueUtils() { }
+
+ public static long combineWithValue(long key, long value, int keyBits) {
+ Preconditions.checkArgument(keyBits >= 0 && keyBits <= 64, "keyBits must be [0,64]");
+
+ int valueBits = 64 - keyBits;
+ long valueMask = valueBits == 64 ? 0xFFFFFFFFFFFFFFFFL : (1L << valueBits) - 1;
+
+ return key ^ (value & valueMask);
+ }
+
+ public static int prefixBits(long raw1, int numBits) {
+ Preconditions.checkArgument(numBits >= 0 && numBits <= 32,
+ "numBits must be in range [0, 32]");
+
+ if(numBits == 0)
+ return 0;
+
+ final int shiftDown = 64 - numBits;
+
+ return (int) (raw1 >>> shiftDown);
+ }
+
+}