/*
* Copyright 2015 Goldman Sachs.
* Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 8154049
* @summary Tests the sorting of a large array of sorted primitive values,
* predominently for cases where the array is nearly sorted. This tests
* code that detects patterns in the array to determine if it is nearly
* sorted and if so employs and optimizes merge sort rather than a
* Dual-Pivot QuickSort.
*
* @run testng SortingNearlySortedPrimitive
*/
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.StringJoiner;
import java.util.function.IntFunction;
import java.util.stream.IntStream;
import java.util.stream.Stream;
public class SortingNearlySortedPrimitive {
static final int BASE = 3;
static final int WIDTH = 4;
// Should be > DualPivotQuicksort.QUICKSORT_THRESHOLD
static final int PAD = 300;
Stream<int[]> createCombinations() {
// Create all combinations for the BASE value and double the WIDTH
// elements
// This is create various combinations of ascending, descending and
// equal runs to exercise the nearly sorted code paths
return IntStream.range(0, (int) Math.pow(BASE, 2 * WIDTH)).
mapToObj(this::createArray);
}
// Create an array which at either end is filled with -ve and +ve elements
// according to the base value and padded with zeros in between
int[] createArray(int v) {
int[] a = new int[WIDTH + PAD + WIDTH];
// Fill head of array
for (int j = 0; j < WIDTH; j++) {
a[j] = (v % BASE) - (BASE / 2);
v /= BASE;
}
// Fill tail of array
for (int j = 0; j < WIDTH; j++) {
a[WIDTH + PAD + j] = (v % BASE) - (BASE / 2);
v /= BASE;
}
return a;
}
@Test
public void testCombination() {
createCombinations().forEach(a -> {
try {
// Clone source array to ensure it is not modified
this.sortAndAssert(a.clone());
this.sortAndAssert(floatCopyFromInt(a));
this.sortAndAssert(doubleCopyFromInt(a));
this.sortAndAssert(longCopyFromInt(a));
this.sortAndAssert(shortCopyFromInt(a));
this.sortAndAssert(charCopyFromInt(a));
} catch (AssertionError sae) {
AssertionError ae = new AssertionError("Sort failed for " + arrayToString(a));
ae.addSuppressed(sae);
throw ae;
}
});
}
String arrayToString(int[] a) {
int[] l = Arrays.copyOfRange(a, 0, WIDTH + 2);
int[] r = Arrays.copyOfRange(a, a.length - (WIDTH + 2), a.length);
StringJoiner sj = new StringJoiner(",", "[", "]");
for (int i : l) {
sj.add(Integer.toString(i));
}
sj.add("...");
for (int i : r) {
sj.add(Integer.toString(i));
}
return sj.toString();
}
@DataProvider(name = "shapes")
public Object[][] createShapes() {
Stream<List<Object>> baseCases = Stream.of(
List.of("hiZeroLowTest", (IntFunction<int[]>) this::hiZeroLowData),
List.of("endLessThanTest", (IntFunction<int[]>) this::endLessThanData),
List.of("highFlatLowTest", (IntFunction<int[]>) this::highFlatLowData),
List.of("identicalTest", (IntFunction<int[]>) this::identicalData),
List.of("sortedReversedSortedTest", (IntFunction<int[]>) this::sortedReversedSortedData),
List.of("pairFlipTest", (IntFunction<int[]>) this::pairFlipData),
List.of("zeroHiTest", (IntFunction<int[]>) this::zeroHiData)
);
// Ensure the following inequality holds for certain sizes
// DualPivotQuicksort.QUICKSORT_THRESHOLD <= size - 1
// < DualPivotQuicksort.COUNTING_SORT_THRESHOLD_FOR_SHORT_OR_CHAR
// This guarantees that code paths are taken for checking nearly sorted
// arrays for all primitive types
List<Integer> sizes = List.of(100, 1_000, 10_000, 1_000_000);
return baseCases.
flatMap(l -> sizes.stream().map(s -> append(l, s))).
toArray(Object[][]::new);
}
Object[] append(List<Object> l, Object value) {
List<Object> nl = new ArrayList<>(l);
nl.add(value);
return nl.toArray();
}
@Test(dataProvider = "shapes")
public void testShapes(String testName, IntFunction<int[]> dataMethod, int size) {
int[] intSourceArray = dataMethod.apply(size);
// Clone source array to ensure it is not modified
this.sortAndAssert(intSourceArray.clone());
this.sortAndAssert(floatCopyFromInt(intSourceArray));
this.sortAndAssert(doubleCopyFromInt(intSourceArray));
this.sortAndAssert(longCopyFromInt(intSourceArray));
this.sortAndAssert(shortCopyFromInt(intSourceArray));
this.sortAndAssert(charCopyFromInt(intSourceArray));
}
private float[] floatCopyFromInt(int[] src) {
float[] result = new float[src.length];
for (int i = 0; i < result.length; i++) {
result[i] = src[i];
}
return result;
}
private double[] doubleCopyFromInt(int[] src) {
double[] result = new double[src.length];
for (int i = 0; i < result.length; i++) {
result[i] = src[i];
}
return result;
}
private long[] longCopyFromInt(int[] src) {
long[] result = new long[src.length];
for (int i = 0; i < result.length; i++) {
result[i] = src[i];
}
return result;
}
private short[] shortCopyFromInt(int[] src) {
short[] result = new short[src.length];
for (int i = 0; i < result.length; i++) {
result[i] = (short) src[i];
}
return result;
}
private char[] charCopyFromInt(int[] src) {
char[] result = new char[src.length];
for (int i = 0; i < result.length; i++) {
result[i] = (char) src[i];
}
return result;
}
private void sortAndAssert(int[] array) {
Arrays.sort(array);
for (int i = 1; i < array.length; i++) {
if (array[i] < array[i - 1]) {
throw new AssertionError("not sorted");
}
}
}
private void sortAndAssert(char[] array) {
Arrays.sort(array);
for (int i = 1; i < array.length; i++) {
if (array[i] < array[i - 1]) {
throw new AssertionError("not sorted");
}
}
}
private void sortAndAssert(short[] array) {
Arrays.sort(array);
for (int i = 1; i < array.length; i++) {
if (array[i] < array[i - 1]) {
throw new AssertionError("not sorted");
}
}
}
private void sortAndAssert(double[] array) {
Arrays.sort(array);
for (int i = 1; i < array.length; i++) {
if (array[i] < array[i - 1]) {
throw new AssertionError("not sorted");
}
}
}
private void sortAndAssert(float[] array) {
Arrays.sort(array);
for (int i = 1; i < array.length; i++) {
if (array[i] < array[i - 1]) {
throw new AssertionError("not sorted");
}
}
}
private void sortAndAssert(long[] array) {
Arrays.sort(array);
for (int i = 1; i < array.length; i++) {
if (array[i] < array[i - 1]) {
throw new AssertionError("not sorted");
}
}
}
private int[] zeroHiData(int size) {
int[] array = new int[size];
int threeQuarters = (int) (size * 0.75);
for (int i = 0; i < threeQuarters; i++) {
array[i] = 0;
}
int k = 1;
for (int i = threeQuarters; i < size; i++) {
array[i] = k;
k++;
}
return array;
}
private int[] hiZeroLowData(int size) {
int[] array = new int[size];
int oneThird = size / 3;
for (int i = 0; i < oneThird; i++) {
array[i] = i;
}
int twoThirds = oneThird * 2;
for (int i = oneThird; i < twoThirds; i++) {
array[i] = 0;
}
for (int i = twoThirds; i < size; i++) {
array[i] = oneThird - i + twoThirds;
}
return array;
}
private int[] highFlatLowData(int size) {
int[] array = new int[size];
int oneThird = size / 3;
for (int i = 0; i < oneThird; i++) {
array[i] = i;
}
int twoThirds = oneThird * 2;
int constant = oneThird - 1;
for (int i = oneThird; i < twoThirds; i++) {
array[i] = constant;
}
for (int i = twoThirds; i < size; i++) {
array[i] = constant - i + twoThirds;
}
return array;
}
private int[] identicalData(int size) {
int[] array = new int[size];
int listNumber = 24;
for (int i = 0; i < size; i++) {
array[i] = listNumber;
}
return array;
}
private int[] endLessThanData(int size) {
int[] array = new int[size];
for (int i = 0; i < size - 1; i++) {
array[i] = 3;
}
array[size - 1] = 1;
return array;
}
private int[] sortedReversedSortedData(int size) {
int[] array = new int[size];
for (int i = 0; i < size / 2; i++) {
array[i] = i;
}
int num = 0;
for (int i = size / 2; i < size; i++) {
array[i] = size - num;
num++;
}
return array;
}
private int[] pairFlipData(int size) {
int[] array = new int[size];
for (int i = 0; i < size; i++) {
array[i] = i;
}
for (int i = 0; i < size; i += 2) {
int temp = array[i];
array[i] = array[i + 1];
array[i + 1] = temp;
}
return array;
}
}