/*
* Copyright 2015 Goldman Sachs.
* Copyright (c) 2015, 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.
*/
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Warmup;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Random;
import java.util.Set;
import java.util.concurrent.TimeUnit;
@State(Scope.Thread)
@BenchmarkMode(Mode.Throughput)
@OutputTimeUnit(TimeUnit.SECONDS)
public class SortingLongBenchmarkTestJMH {
private static final int QUICKSORT_THRESHOLD = 286;
private static final int MAX_RUN_COUNT = 67;
private static final int INSERTION_SORT_THRESHOLD = 47;
public static final int MAX_VALUE = 1_000_000;
@Param({"pairFlipZeroPairFlip", "descendingAscending", "zeroHi", "hiZeroLow", "hiFlatLow", "identical",
"randomDups", "randomNoDups", "sortedReversedSorted", "pairFlip", "endLessThan"})
public String listType;
private long[] array;
private static final int LIST_SIZE = 10_000_000;
public static final int NUMBER_OF_ITERATIONS = 10;
@Setup
public void setUp() {
Random random = new Random(123456789012345L);
this.array = new long[LIST_SIZE];
int threeQuarters = (int) (LIST_SIZE * 0.75);
if ("zeroHi".equals(this.listType)) {
for (int i = 0; i < threeQuarters; i++) {
this.array[i] = 0;
}
int k = 1;
for (int i = threeQuarters; i < LIST_SIZE; i++) {
this.array[i] = k;
k++;
}
}
else if ("hiFlatLow".equals(this.listType)) {
int oneThird = LIST_SIZE / 3;
for (int i = 0; i < oneThird; i++) {
this.array[i] = i;
}
int twoThirds = oneThird * 2;
int constant = oneThird - 1;
for (int i = oneThird; i < twoThirds; i++) {
this.array[i] = constant;
}
for (int i = twoThirds; i < LIST_SIZE; i++) {
this.array[i] = constant - i + twoThirds;
}
}
else if ("hiZeroLow".equals(this.listType)) {
int oneThird = LIST_SIZE / 3;
for (int i = 0; i < oneThird; i++) {
this.array[i] = i;
}
int twoThirds = oneThird * 2;
for (int i = oneThird; i < twoThirds; i++) {
this.array[i] = 0;
}
for (int i = twoThirds; i < LIST_SIZE; i++) {
this.array[i] = oneThird - i + twoThirds;
}
}
else if ("identical".equals(this.listType)) {
for (int i = 0; i < LIST_SIZE; i++) {
this.array[i] = 0;
}
}
else if ("randomDups".equals(this.listType)) {
for (int i = 0; i < LIST_SIZE; i++) {
this.array[i] = random.nextInt(1000);
}
}
else if ("randomNoDups".equals(this.listType)) {
Set<Integer> set = new HashSet<>();
while (set.size() < LIST_SIZE + 1) {
set.add(random.nextInt());
}
List<Integer> list = new ArrayList<>(LIST_SIZE);
list.addAll(set);
for (int i = 0; i < LIST_SIZE; i++) {
this.array[i] = list.get(i);
}
}
else if ("sortedReversedSorted".equals(this.listType)) {
for (int i = 0; i < LIST_SIZE / 2; i++) {
this.array[i] = i;
}
int num = 0;
for (int i = LIST_SIZE / 2; i < LIST_SIZE; i++) {
this.array[i] = LIST_SIZE - num;
num++;
}
}
else if ("pairFlip".equals(this.listType)) {
for (int i = 0; i < LIST_SIZE; i++) {
this.array[i] = i;
}
for (int i = 0; i < LIST_SIZE; i += 2) {
long temp = this.array[i];
this.array[i] = this.array[i + 1];
this.array[i + 1] = temp;
}
}
else if ("endLessThan".equals(this.listType)) {
for (int i = 0; i < LIST_SIZE - 1; i++) {
this.array[i] = 3;
}
this.array[LIST_SIZE - 1] = 1;
}
else if ("pairFlipZeroPairFlip".equals(this.listType)) {
//pairflip
for (int i = 0; i < 64; i++) {
this.array[i] = i;
}
for (int i = 0; i < 64; i += 2) {
long temp = this.array[i];
this.array[i] = this.array[i + 1];
this.array[i + 1] = temp;
}
//zero
for (int i = 64; i < this.array.length - 64; i++) {
this.array[i] = 0;
}
//pairflip
for (int i = this.array.length - 64; i < this.array.length; i++) {
this.array[i] = i;
}
for (int i = this.array.length - 64; i < this.array.length; i += 2) {
long temp = this.array[i];
this.array[i] = this.array[i + 1];
this.array[i + 1] = temp;
}
}
else if ("pairFlipOneHundredPairFlip".equals(this.listType)) {
//10, 5
for (int i = 0; i < 64; i++) {
if (i % 2 == 0) {
this.array[i] = 10;
}
else {
this.array[i] = 5;
}
}
//100
for (int i = 64; i < this.array.length - 64; i++) {
this.array[i] = 100;
}
//10, 5
for (int i = this.array.length - 64; i < this.array.length; i++) {
if (i % 2 == 0) {
this.array[i] = 10;
}
else {
this.array[i] = 5;
}
}
}
}
@Warmup(iterations = 20)
@Measurement(iterations = 10)
@Benchmark
public void sortNewWay() {
for (int i = 0; i < NUMBER_OF_ITERATIONS; i++) {
SortingLongTestJMH.sort(this.array, 0, this.array.length - 1, null, 0, 0);
}
}
@Warmup(iterations = 20)
@Measurement(iterations = 10)
@Benchmark
public void sortOldWay() {
for (int i = 0; i < NUMBER_OF_ITERATIONS; i++) {
Arrays.sort(this.array);
}
}
/**
* Sorts the specified range of the array using the given
* workspace array slice if possible for merging
*
* @param a the array to be sorted
* @param left the index of the first element, inclusive, to be sorted
* @param right the index of the last element, inclusive, to be sorted
* @param work a workspace array (slice)
* @param workBase origin of usable space in work array
* @param workLen usable size of work array
*/
static void sort(long[] a, int left, int right,
long[] work, int workBase, int workLen) {
// Use Quicksort on small arrays
if (right - left < QUICKSORT_THRESHOLD) {
SortingLongTestJMH.sort(a, left, right, true);
return;
}
/*
* Index run[i] is the start of i-th run
* (ascending or descending sequence).
*/
int[] run = new int[MAX_RUN_COUNT + 1];
int count = 0;
run[0] = left;
// Check if the array is nearly sorted
for (int k = left; k < right; run[count] = k) {
while (k < right && a[k] == a[k + 1])
k++;
if (k == right) break;
if (a[k] < a[k + 1]) { // ascending
while (++k <= right && a[k - 1] <= a[k]) ;
}
else if (a[k] > a[k + 1]) { // descending
while (++k <= right && a[k - 1] >= a[k]) ;
for (int lo = run[count] - 1, hi = k; ++lo < --hi; ) {
long t = a[lo];
a[lo] = a[hi];
a[hi] = t;
}
}
if (run[count] > left && a[run[count]] >= a[run[count] - 1]) {
count--;
}
/*
* The array is not highly structured,
* use Quicksort instead of merge sort.
*/
if (++count == MAX_RUN_COUNT) {
sort(a, left, right, true);
return;
}
}
// Check special cases
// Implementation note: variable "right" is increased by 1.
if (run[count] == right++) {
run[++count] = right;
}
if (count <= 1) { // The array is already sorted
return;
}
// Determine alternation base for merge
byte odd = 0;
for (int n = 1; (n <<= 1) < count; odd ^= 1) {
}
// Use or create temporary array b for merging
long[] b; // temp array; alternates with a
int ao, bo; // array offsets from 'left'
int blen = right - left; // space needed for b
if (work == null || workLen < blen || workBase + blen > work.length) {
work = new long[blen];
workBase = 0;
}
if (odd == 0) {
System.arraycopy(a, left, work, workBase, blen);
b = a;
bo = 0;
a = work;
ao = workBase - left;
}
else {
b = work;
ao = 0;
bo = workBase - left;
}
// Merging
for (int last; count > 1; count = last) {
for (int k = (last = 0) + 2; k <= count; k += 2) {
int hi = run[k], mi = run[k - 1];
for (int i = run[k - 2], p = i, q = mi; i < hi; ++i) {
if (q >= hi || p < mi && a[p + ao] <= a[q + ao]) {
b[i + bo] = a[p++ + ao];
}
else {
b[i + bo] = a[q++ + ao];
}
}
run[++last] = hi;
}
if ((count & 1) != 0) {
for (int i = right, lo = run[count - 1]; --i >= lo;
b[i + bo] = a[i + ao]
) {
}
run[++last] = right;
}
long[] t = a;
a = b;
b = t;
int o = ao;
ao = bo;
bo = o;
}
}
/**
* Sorts the specified range of the array by Dual-Pivot Quicksort.
*
* @param a the array to be sorted
* @param left the index of the first element, inclusive, to be sorted
* @param right the index of the last element, inclusive, to be sorted
* @param leftmost indicates if this part is the leftmost in the range
*/
private static void sort(long[] a, int left, int right, boolean leftmost) {
int length = right - left + 1;
// Use insertion sort on tiny arrays
if (length < INSERTION_SORT_THRESHOLD) {
if (leftmost) {
/*
* Traditional (without sentinel) insertion sort,
* optimized for server VM, is used in case of
* the leftmost part.
*/
for (int i = left, j = i; i < right; j = ++i) {
long ai = a[i + 1];
while (ai < a[j]) {
a[j + 1] = a[j];
if (j-- == left) {
break;
}
}
a[j + 1] = ai;
}
}
else {
/*
* Skip the longest ascending sequence.
*/
do {
if (left >= right) {
return;
}
}
while (a[++left] >= a[left - 1]);
/*
* Every element from adjoining part plays the role
* of sentinel, therefore this allows us to avoid the
* left range check on each iteration. Moreover, we use
* the more optimized algorithm, so called pair insertion
* sort, which is faster (in the context of Quicksort)
* than traditional implementation of insertion sort.
*/
for (int k = left; ++left <= right; k = ++left) {
long a1 = a[k], a2 = a[left];
if (a1 < a2) {
a2 = a1;
a1 = a[left];
}
while (a1 < a[--k]) {
a[k + 2] = a[k];
}
a[++k + 1] = a1;
while (a2 < a[--k]) {
a[k + 1] = a[k];
}
a[k + 1] = a2;
}
long last = a[right];
while (last < a[--right]) {
a[right + 1] = a[right];
}
a[right + 1] = last;
}
return;
}
// Inexpensive approximation of length / 7
int seventh = (length >> 3) + (length >> 6) + 1;
/*
* Sort five evenly spaced elements around (and including) the
* center element in the range. These elements will be used for
* pivot selection as described below. The choice for spacing
* these elements was empirically determined to work well on
* a wide variety of inputs.
*/
int e3 = (left + right) >>> 1; // The midpoint
int e2 = e3 - seventh;
int e1 = e2 - seventh;
int e4 = e3 + seventh;
int e5 = e4 + seventh;
// Sort these elements using insertion sort
if (a[e2] < a[e1]) {
long t = a[e2];
a[e2] = a[e1];
a[e1] = t;
}
if (a[e3] < a[e2]) {
long t = a[e3];
a[e3] = a[e2];
a[e2] = t;
if (t < a[e1]) {
a[e2] = a[e1];
a[e1] = t;
}
}
if (a[e4] < a[e3]) {
long t = a[e4];
a[e4] = a[e3];
a[e3] = t;
if (t < a[e2]) {
a[e3] = a[e2];
a[e2] = t;
if (t < a[e1]) {
a[e2] = a[e1];
a[e1] = t;
}
}
}
if (a[e5] < a[e4]) {
long t = a[e5];
a[e5] = a[e4];
a[e4] = t;
if (t < a[e3]) {
a[e4] = a[e3];
a[e3] = t;
if (t < a[e2]) {
a[e3] = a[e2];
a[e2] = t;
if (t < a[e1]) {
a[e2] = a[e1];
a[e1] = t;
}
}
}
}
// Pointers
int less = left; // The index of the first element of center part
int great = right; // The index before the first element of right part
if (a[e1] != a[e2] && a[e2] != a[e3] && a[e3] != a[e4] && a[e4] != a[e5]) {
/*
* Use the second and fourth of the five sorted elements as pivots.
* These values are inexpensive approximations of the first and
* second terciles of the array. Note that pivot1 <= pivot2.
*/
long pivot1 = a[e2];
long pivot2 = a[e4];
/*
* The first and the last elements to be sorted are moved to the
* locations formerly occupied by the pivots. When partitioning
* is complete, the pivots are swapped back into their final
* positions, and excluded from subsequent sorting.
*/
a[e2] = a[left];
a[e4] = a[right];
/*
* Skip elements, which are less or greater than pivot values.
*/
while (a[++less] < pivot1) {
}
while (a[--great] > pivot2) {
}
/*
* Partitioning:
*
* left part center part right part
* +--------------------------------------------------------------+
* | < pivot1 | pivot1 <= && <= pivot2 | ? | > pivot2 |
* +--------------------------------------------------------------+
* ^ ^ ^
* | | |
* less k great
*
* Invariants:
*
* all in (left, less) < pivot1
* pivot1 <= all in [less, k) <= pivot2
* all in (great, right) > pivot2
*
* Pointer k is the first index of ?-part.
*/
outer:
for (int k = less - 1; ++k <= great; ) {
long ak = a[k];
if (ak < pivot1) { // Move a[k] to left part
a[k] = a[less];
/*
* Here and below we use "a[i] = b; i++;" instead
* of "a[i++] = b;" due to performance issue.
*/
a[less] = ak;
++less;
}
else if (ak > pivot2) { // Move a[k] to right part
while (a[great] > pivot2) {
if (great-- == k) {
break outer;
}
}
if (a[great] < pivot1) { // a[great] <= pivot2
a[k] = a[less];
a[less] = a[great];
++less;
}
else { // pivot1 <= a[great] <= pivot2
a[k] = a[great];
}
/*
* Here and below we use "a[i] = b; i--;" instead
* of "a[i--] = b;" due to performance issue.
*/
a[great] = ak;
--great;
}
}
// Swap pivots into their final positions
a[left] = a[less - 1];
a[less - 1] = pivot1;
a[right] = a[great + 1];
a[great + 1] = pivot2;
// Sort left and right parts recursively, excluding known pivots
SortingLongTestJMH.sort(a, left, less - 2, leftmost);
SortingLongTestJMH.sort(a, great + 2, right, false);
/*
* If center part is too large (comprises > 4/7 of the array),
* swap internal pivot values to ends.
*/
if (less < e1 && e5 < great) {
/*
* Skip elements, which are equal to pivot values.
*/
while (a[less] == pivot1) {
++less;
}
while (a[great] == pivot2) {
--great;
}
/*
* Partitioning:
*
* left part center part right part
* +----------------------------------------------------------+
* | == pivot1 | pivot1 < && < pivot2 | ? | == pivot2 |
* +----------------------------------------------------------+
* ^ ^ ^
* | | |
* less k great
*
* Invariants:
*
* all in (*, less) == pivot1
* pivot1 < all in [less, k) < pivot2
* all in (great, *) == pivot2
*
* Pointer k is the first index of ?-part.
*/
outer:
for (int k = less - 1; ++k <= great; ) {
long ak = a[k];
if (ak == pivot1) { // Move a[k] to left part
a[k] = a[less];
a[less] = ak;
++less;
}
else if (ak == pivot2) { // Move a[k] to right part
while (a[great] == pivot2) {
if (great-- == k) {
break outer;
}
}
if (a[great] == pivot1) { // a[great] < pivot2
a[k] = a[less];
/*
* Even though a[great] equals to pivot1, the
* assignment a[less] = pivot1 may be incorrect,
* if a[great] and pivot1 are floating-point zeros
* of different signs. Therefore in float and
* double sorting methods we have to use more
* accurate assignment a[less] = a[great].
*/
a[less] = pivot1;
++less;
}
else { // pivot1 < a[great] < pivot2
a[k] = a[great];
}
a[great] = ak;
--great;
}
}
}
// Sort center part recursively
SortingLongTestJMH.sort(a, less, great, false);
}
else { // Partitioning with one pivot
/*
* Use the third of the five sorted elements as pivot.
* This value is inexpensive approximation of the median.
*/
long pivot = a[e3];
/*
* Partitioning degenerates to the traditional 3-way
* (or "Dutch National Flag") schema:
*
* left part center part right part
* +-------------------------------------------------+
* | < pivot | == pivot | ? | > pivot |
* +-------------------------------------------------+
* ^ ^ ^
* | | |
* less k great
*
* Invariants:
*
* all in (left, less) < pivot
* all in [less, k) == pivot
* all in (great, right) > pivot
*
* Pointer k is the first index of ?-part.
*/
for (int k = less; k <= great; ++k) {
if (a[k] == pivot) {
continue;
}
long ak = a[k];
if (ak < pivot) { // Move a[k] to left part
a[k] = a[less];
a[less] = ak;
++less;
}
else { // a[k] > pivot - Move a[k] to right part
while (a[great] > pivot) {
--great;
}
if (a[great] < pivot) { // a[great] <= pivot
a[k] = a[less];
a[less] = a[great];
++less;
}
else { // a[great] == pivot
/*
* Even though a[great] equals to pivot, the
* assignment a[k] = pivot may be incorrect,
* if a[great] and pivot are floating-point
* zeros of different signs. Therefore in float
* and double sorting methods we have to use
* more accurate assignment a[k] = a[great].
*/
a[k] = pivot;
}
a[great] = ak;
--great;
}
}
/*
* Sort left and right parts recursively.
* All elements from center part are equal
* and, therefore, already sorted.
*/
SortingLongTestJMH.sort(a, left, less - 1, leftmost);
SortingLongTestJMH.sort(a, great + 1, right, false);
}
}
private static void swap(long[] arr, int i, int j) {
long tmp = arr[i];
arr[i] = arr[j];
arr[j] = tmp;
}
}