From 7811be77abafa7b545a8da0ba13a6099d64ebf11 Mon Sep 17 00:00:00 2001
From: Alexey Zinchenko <alexey.zinchenko@protonmail.com>
Date: Fri, 8 Mar 2019 23:19:43 +0300
Subject: [PATCH] Added benchmarks for bubble, selection, insertion, merge and
 default(Arrays class) sort.

---
 .gitignore                                    |  6 ++
 pom.xml                                       | 71 +++++++++++++++++++
 src/main/java/com/github/prominence/Main.java | 12 ++++
 .../benchmark/SortingBenchmark.java           | 59 +++++++++++++++
 .../github/prominence/sort/BubbleSort.java    | 16 +++++
 .../github/prominence/sort/InsertionSort.java | 16 +++++
 .../com/github/prominence/sort/MergeSort.java | 31 ++++++++
 .../github/prominence/sort/SelectionSort.java | 19 +++++
 8 files changed, 230 insertions(+)
 create mode 100644 pom.xml
 create mode 100644 src/main/java/com/github/prominence/Main.java
 create mode 100644 src/main/java/com/github/prominence/benchmark/SortingBenchmark.java
 create mode 100644 src/main/java/com/github/prominence/sort/BubbleSort.java
 create mode 100644 src/main/java/com/github/prominence/sort/InsertionSort.java
 create mode 100644 src/main/java/com/github/prominence/sort/MergeSort.java
 create mode 100644 src/main/java/com/github/prominence/sort/SelectionSort.java

diff --git a/.gitignore b/.gitignore
index a1c2a23..aae491d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,3 +21,9 @@
 
 # virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
 hs_err_pid*
+
+
+.idea
+dependency-reduced-pom.xml
+*.iml
+target
\ No newline at end of file
diff --git a/pom.xml b/pom.xml
new file mode 100644
index 0000000..ee4d1e5
--- /dev/null
+++ b/pom.xml
@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.github.prominence</groupId>
+    <artifactId>sorting-benchmark</artifactId>
+    <version>1.0</version>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>8</source>
+                    <target>8</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>2.2</version>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                            <finalName>sorting-benchmark</finalName>
+                            <transformers>
+                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                    <mainClass>org.openjdk.jmh.Main</mainClass>
+                                </transformer>
+                            </transformers>
+                            <filters>
+                                <filter>
+                                    <!--
+                                        Shading signed JARs will fail without this.
+                                        http://stackoverflow.com/questions/999489/invalid-signature-file-when-attempting-to-run-a-jar
+                                    -->
+                                    <artifact>*:*</artifact>
+                                    <excludes>
+                                        <exclude>META-INF/*.SF</exclude>
+                                        <exclude>META-INF/*.DSA</exclude>
+                                        <exclude>META-INF/*.RSA</exclude>
+                                    </excludes>
+                                </filter>
+                            </filters>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>1.21</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>1.21</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+</project>
\ No newline at end of file
diff --git a/src/main/java/com/github/prominence/Main.java b/src/main/java/com/github/prominence/Main.java
new file mode 100644
index 0000000..1643f91
--- /dev/null
+++ b/src/main/java/com/github/prominence/Main.java
@@ -0,0 +1,12 @@
+package com.github.prominence;
+
+import org.openjdk.jmh.runner.RunnerException;
+
+import java.io.IOException;
+
+public class Main {
+
+    public static void main(String[] args) throws IOException, RunnerException {
+        org.openjdk.jmh.Main.main(args);
+    }
+}
diff --git a/src/main/java/com/github/prominence/benchmark/SortingBenchmark.java b/src/main/java/com/github/prominence/benchmark/SortingBenchmark.java
new file mode 100644
index 0000000..175623e
--- /dev/null
+++ b/src/main/java/com/github/prominence/benchmark/SortingBenchmark.java
@@ -0,0 +1,59 @@
+package com.github.prominence.benchmark;
+
+import com.github.prominence.sort.BubbleSort;
+import com.github.prominence.sort.InsertionSort;
+import com.github.prominence.sort.MergeSort;
+import com.github.prominence.sort.SelectionSort;
+import org.openjdk.jmh.annotations.*;
+
+import java.util.Arrays;
+import java.util.stream.IntStream;
+
+public class SortingBenchmark {
+
+    @State(Scope.Benchmark)
+    public static class MyState {
+        private int[] basicData;
+
+        {
+            String launchProperty = System.getProperty("array.size");
+            int arraySize = launchProperty != null ? Integer.valueOf(launchProperty) : 100000;
+
+            basicData = IntStream.generate(() -> (int) (Math.random() * 10000)).limit(arraySize).toArray();
+        }
+
+        int[] getData() {
+            return Arrays.copyOf(basicData, basicData.length);
+        }
+    }
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public void javaDefaultSort(MyState myState) {
+        Arrays.sort(myState.getData());
+    }
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public void bubbleSort(MyState state) {
+        BubbleSort.sort(state.getData());
+    }
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public void selectionSort(MyState state) {
+        SelectionSort.sort(state.getData());
+    }
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public void insertionSort(MyState state) {
+        InsertionSort.sort(state.getData());
+    }
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public void mergeSort(MyState state) {
+        MergeSort.sort(state.getData());
+    }
+}
diff --git a/src/main/java/com/github/prominence/sort/BubbleSort.java b/src/main/java/com/github/prominence/sort/BubbleSort.java
new file mode 100644
index 0000000..e4047e6
--- /dev/null
+++ b/src/main/java/com/github/prominence/sort/BubbleSort.java
@@ -0,0 +1,16 @@
+package com.github.prominence.sort;
+
+public class BubbleSort {
+
+    public static void sort(int[] array) {
+        for (int i = 0; i < array.length; i++) {
+            for (int j = 0; j < array.length - i - 1; j++) {
+                if (array[j + 1] < array[j]) {
+                    int tmp = array[j + 1];
+                    array[j + 1] = array[j];
+                    array[j] = tmp;
+                }
+            }
+        }
+    }
+}
diff --git a/src/main/java/com/github/prominence/sort/InsertionSort.java b/src/main/java/com/github/prominence/sort/InsertionSort.java
new file mode 100644
index 0000000..4033fc1
--- /dev/null
+++ b/src/main/java/com/github/prominence/sort/InsertionSort.java
@@ -0,0 +1,16 @@
+package com.github.prominence.sort;
+
+public class InsertionSort {
+
+    public static void sort(int[] array) {
+        for (int i = 1; i < array.length; i++) {
+            for (int j = i; j > 0; j--) {
+                if (array[j - 1] > array[j]) {
+                    int tmp = array[j - 1];
+                    array[j - 1] = array[j];
+                    array[j] = tmp;
+                }
+            }
+        }
+    }
+}
diff --git a/src/main/java/com/github/prominence/sort/MergeSort.java b/src/main/java/com/github/prominence/sort/MergeSort.java
new file mode 100644
index 0000000..b159135
--- /dev/null
+++ b/src/main/java/com/github/prominence/sort/MergeSort.java
@@ -0,0 +1,31 @@
+package com.github.prominence.sort;
+
+public class MergeSort {
+
+    public static void sort(int[] array) {
+        int[] aux = new int[array.length];
+
+        mergeSort(array, aux, 0, array.length);
+    }
+
+    private static void mergeSort(int[] array, int[] aux, int lo, int hi) {
+        if (hi - lo <= 1) return;
+        int mid = lo + (hi - lo) / 2;
+        mergeSort(array, aux, lo, mid);
+        mergeSort(array, aux, mid, hi);
+        int i = lo;
+        int j = mid;
+        for (int k = lo; k < hi; k++) {
+            if (i == mid) {
+                aux[k] = array[j++];
+            } else if (j == hi) {
+                aux[k] = array[i++];
+            } else if (array[j] < array[i]) {
+                aux[k] = array[j++];
+            } else {
+                aux[k] = array[i++];
+            }
+        }
+        System.arraycopy(aux, lo, array, lo, hi - lo);
+    }
+}
diff --git a/src/main/java/com/github/prominence/sort/SelectionSort.java b/src/main/java/com/github/prominence/sort/SelectionSort.java
new file mode 100644
index 0000000..ad63d38
--- /dev/null
+++ b/src/main/java/com/github/prominence/sort/SelectionSort.java
@@ -0,0 +1,19 @@
+package com.github.prominence.sort;
+
+public class SelectionSort {
+
+    public static void sort(int[] array) {
+        for (int i = 0; i < array.length-1; i++) {
+            int min_idx = i;
+            for (int j = i+1; j < array.length; j++) {
+                if (array[j] < array[min_idx]) {
+                    min_idx = j;
+                }
+            }
+
+            int tmp = array[min_idx];
+            array[min_idx] = array[i];
+            array[i] = tmp;
+        }
+    }
+}