Added an example demonstrating when valueCompare can be useful.

java/src/test/java/net/razorvine/examples/ValueCompareExample.java

@@ -0,0 +1,54 @@
+package net.razorvine.examples;
+
+import java.util.*;
+import java.io.IOException;
+
+import net.razorvine.pickle.Pickler;
+import net.razorvine.pickle.Unpickler;
+
+public class ValueCompareExample {
+
+    public static void main(String[] args) throws IOException {
+
+        Random random = new Random(1337);
+        List<String> values = new ArrayList<String>();
+        for (int i = 0; i < 100000; ++i) {
+            values.add(("This is a string with a number in it: " + random.nextInt(100))
+                    // .intern() // You could also see what happens when the strings are interned
+            );
+        }
+
+        long t0 = System.nanoTime();
+        byte[] noValueCompare = new Pickler(true, false).dumps(values);
+        long t1 = System.nanoTime();
+        byte[] withValueCompare = new Pickler(true, true).dumps(values);
+        long t2 = System.nanoTime();
+
+        System.out.println("Pickle size without: " + noValueCompare.length + "B, with: " + withValueCompare.length + "B"
+                + " (" + (int) ((1 - withValueCompare.length / (double) noValueCompare.length) * 100.0) + "% smaller)");
+
+        Unpickler unpickler = new Unpickler();
+
+        long t3 = System.nanoTime();
+        List<String> without = (List<String>) unpickler.loads(noValueCompare);
+        long t4 = System.nanoTime();
+        List<String> with = (List<String>) unpickler.loads(withValueCompare);
+        long t5 = System.nanoTime();
+
+        System.out.println("Whole List equality: ==: " + (without == with) + ", .equals(): " + (without.equals(with)));
+
+        System.out.println(
+                "Two equal elements equality without valueCompare: ==: " + (without.get(107) == without.get(259))
+                        + ", .equals(): " + (without.get(107).equals(without.get(259))));
+        System.out.println("Two equal elements equality with valueCompare: ==: " + (with.get(107) == with.get(259))
+                + ", .equals(): " + (with.get(107).equals(with.get(259))));
+
+        System.out.println("Pickling without valueCompare took " + (t1 - t0) / 1000000.0 + "ms");
+        System.out.println("Pickling with valueCompare took " + (t2 - t1) / 1000000.0 + "ms");
+
+        System.out.println("Unpickling without valueCompare took " + (t4 - t3) / 1000000.0 + "ms");
+        System.out.println("Unpickling with valueCompare took " + (t5 - t4) / 1000000.0 + "ms");
+
+    }
+
+}