benchmark preparations

app/src/main/java/de/uni_marburg/powersort/benchmark/DummySort.java

@@ -8,7 +8,7 @@ import java.util.Comparator;
  * <p>
  * Uses Arrays.sort() for sorting.
  */
-class DummySort<T> {
+class DummySort {
     public static <T> void sort(T[] a, int lo, int hi, Comparator<? super T> c,
                                 T[] work, int workBase, int workLen) {
         assert lo == 0;

app/src/main/java/de/uni_marburg/powersort/benchmark/DummySort2.java

@@ -9,7 +9,7 @@ import java.util.Comparator;
  * Uses Arrays.sort() for sorting.
  * But calls it a.length times which makes this implementation really inefficient.
  */
-class DummySort2<T> {
+class DummySort2 {
     public static <T> void sort(T[] a, int lo, int hi, Comparator<? super T> c,
                                 T[] work, int workBase, int workLen) {
         assert lo == 0;

app/src/main/java/de/uni_marburg/powersort/benchmark/Main.java

@@ -2,34 +2,50 @@ package de.uni_marburg.powersort.benchmark;
 
 import de.uni_marburg.powersort.TimSort;
 
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
 import java.util.Arrays;
-import java.util.Comparator;
 import java.util.List;
 import java.util.function.Supplier;
 
 public class Main {
-    public static void main(final String[] args) throws InvocationTargetException, IllegalAccessException, NoSuchMethodException {
+    public static void main(final String[] args) {
-        final Method[] sortImplementations = getSortImplementations();
+        final SortImpl[] sortImplementations = getSortImplementations();
         final List<Supplier<Object[]>> sortInputSuppliers = getSortInputSuppliers();
 
-        final NaturalOrder c = NaturalOrder.INSTANCE;
         for (Supplier<Object[]> sortInputSupplier : sortInputSuppliers) {
-            for (Method sortImplementation : sortImplementations) {
+            for (SortImpl sortImplementation : sortImplementations) {
                 Object[] sortInput = sortInputSupplier.get();
-                sortImplementation.invoke(null, sortInput, 0, 0, c, null, 0, 0);
+
-                System.out.println(Arrays.toString(sortInput));
+                final long startTime = System.nanoTime();
+                sortImplementation.sort(sortInput);
+                final long stopTime = System.nanoTime();
+                final long duration = stopTime - startTime;
+
+                System.out.println(duration + "," + sortImplementation.title + "," + sortImplementation.description);
             }
         }
     }
 
-    static Method[] getSortImplementations() throws NoSuchMethodException {
+    static SortImpl[] getSortImplementations() {
-        return new Method[]{
+        return new SortImpl[]{
-                DummySort.class.getMethod("sort", Object[].class, int.class, int.class, Comparator.class, Object[].class, int.class, int.class),
+                new SortImpl("DummySort", "DummySort.sort(a,c) uses Arrays.sort(a,c) internally.") {
-                DummySort2.class.getMethod("sort", Object[].class, int.class, int.class, Comparator.class, Object[].class, int.class, int.class),
+                    @Override
+                    public void sort(Object[] a) {
+                        DummySort.sort(a, 0, a.length, NaturalOrder.INSTANCE, null, 0, 0);
+                    }
+                },
+                new SortImpl("DummySort2", "DummySort2.sort(a,c) uses Arrays.sort(a,c) internally. It calles that method multiple times making this implementation really slow.") {
+                    @Override
+                    public void sort(Object[] a) {
+                        DummySort2.sort(a, 0, a.length, NaturalOrder.INSTANCE, null, 0, 0);
+                    }
+                },
                 //
-                TimSort.class.getMethod("sort", Object[].class, int.class, int.class, Comparator.class, Object[].class, int.class, int.class),
+                new SortImpl("TimSort", "Copy of JDK23 TimSort.java") {
+                    @Override
+                    public void sort(Object[] a) {
+                        TimSort.sort(a, 0, a.length, NaturalOrder.INSTANCE, null, 0, 0);
+                    }
+                }
         };
     }
 

app/src/main/java/de/uni_marburg/powersort/benchmark/SortImpl.java

@@ -0,0 +1,22 @@
+package de.uni_marburg.powersort.benchmark;
+
+public abstract class SortImpl {
+    /**
+     * Title of the sort algorithm used.
+     */
+    final String title;
+    /**
+     * Implementation details of the sort algorithm used.
+     */
+    final String description;
+
+    public SortImpl(String title, String description) {
+        this.title = title;
+        this.description = description;
+    }
+
+    /**
+     * Apply the sort algorithm.
+     */
+    public abstract void sort(Object[] a);
+}