- Add kad lib, from i2p.zzz.kademlia branch (without the history),

which is a rewrite of the netdb kad
- Drop now-unused SHA1Comparator
- Efficiency tweak to NodeInfoComparator

apps/i2psnark/java/src/net/i2p/kademlia/XORComparator.java

@@ -0,0 +1,27 @@
+package net.i2p.kademlia;
+
+import java.util.Comparator;
+
+import net.i2p.data.DataHelper;
+import net.i2p.data.SimpleDataStructure;
+
+/**
+ * Help sort Hashes in relation to a base key using the XOR metric
+ *
+ */
+class XORComparator<T extends SimpleDataStructure> implements Comparator<T> {
+    private final byte[] _base;
+
+    /**
+     * @param target key to compare distances with
+     */
+    public XORComparator(T target) {
+        _base = target.getData();
+    }
+
+    public int compare(T lhs, T rhs) {
+        byte lhsDelta[] = DataHelper.xor(lhs.getData(), _base);
+        byte rhsDelta[] = DataHelper.xor(rhs.getData(), _base);
+        return DataHelper.compareTo(lhsDelta, rhsDelta);
+    }
+}