From a8103b9c2e56a19a3443f9b1d62f457b8e7979b1 Mon Sep 17 00:00:00 2001
From: Shautvast <sander.hautvast@top-squad.nl>
Date: Sat, 12 Aug 2023 09:18:37 +0200
Subject: [PATCH] second commit

---
 .gitignore                                    |  35 +++++
 pom.xml                                       |  83 +++++++++++
 .../shautvast/multidim/Int2dArray.class       | Bin 0 -> 515 bytes
 .../github/shautvast/multidim/Int2dArray.java |  30 ++++
 .../github/shautvast/multidim/IntArray.java   |  62 +++++++++
 .../shautvast/multidim/JmhBenchmark.java      | 130 ++++++++++++++++++
 .../shautvast/multidim/IntArrayTest.java      |  28 ++++
 7 files changed, 368 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 pom.xml
 create mode 100644 src/main/java/com/github/shautvast/multidim/Int2dArray.class
 create mode 100644 src/main/java/com/github/shautvast/multidim/Int2dArray.java
 create mode 100644 src/main/java/com/github/shautvast/multidim/IntArray.java
 create mode 100644 src/main/java/com/github/shautvast/multidim/JmhBenchmark.java
 create mode 100644 src/test/java/com/github/shautvast/multidim/IntArrayTest.java

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..d769462
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,35 @@
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store
\ No newline at end of file
diff --git a/pom.xml b/pom.xml
new file mode 100644
index 0000000..2af576d
--- /dev/null
+++ b/pom.xml
@@ -0,0 +1,83 @@
+<?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>org.example</groupId>
+    <artifactId>MultiDim</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>20</maven.compiler.source>
+        <maven.compiler.target>20</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <version>5.9.3</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>1.36</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>1.36</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.8.0</version>
+                <configuration>
+                    <compilerVersion>9</compilerVersion>
+                    <source>9</source>
+                    <target>9</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>3.2.4</version>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                            <finalName>benchmark</finalName>
+                            <transformers>
+                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                    <mainClass>org.openjdk.jmh.Main</mainClass>
+                                </transformer>
+                                <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
+                            </transformers>
+                            <filters>
+                                <filter>
+                                    <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>
+</project>
\ No newline at end of file
diff --git a/src/main/java/com/github/shautvast/multidim/Int2dArray.class b/src/main/java/com/github/shautvast/multidim/Int2dArray.class
new file mode 100644
index 0000000000000000000000000000000000000000..de1ec815f5a59c44f3b95cdf0c5226722700a7b6
GIT binary patch
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diff --git a/src/main/java/com/github/shautvast/multidim/Int2dArray.java b/src/main/java/com/github/shautvast/multidim/Int2dArray.java
new file mode 100644
index 0000000..8af9a4c
--- /dev/null
+++ b/src/main/java/com/github/shautvast/multidim/Int2dArray.java
@@ -0,0 +1,30 @@
+package com.github.shautvast.multidim;
+
+/**
+ * Any dimensional int array, stored as an int[]
+ * No runtime checks! Easy to shoot yourself in the foot!
+ */
+public class Int2dArray {
+    private final int[] data;
+    private int cols;
+
+    public Int2dArray(int rows, int cols) {
+        data = new int[rows * cols];
+        this.cols = cols;
+    }
+
+    public int get(int row, int col) {
+        return row * cols + col;
+    }
+
+    public void set(int row, int col, int val) {
+        data[row * cols + col] = val;
+    }
+
+    int internalSize() {
+        return data.length;
+    }
+
+
+}
+
diff --git a/src/main/java/com/github/shautvast/multidim/IntArray.java b/src/main/java/com/github/shautvast/multidim/IntArray.java
new file mode 100644
index 0000000..701bee5
--- /dev/null
+++ b/src/main/java/com/github/shautvast/multidim/IntArray.java
@@ -0,0 +1,62 @@
+package com.github.shautvast.multidim;
+
+/**
+ * Any dimensional int array, stored as an int[]
+ * No runtime checks! Easy to shoot yourself in the foot!
+ */
+public class IntArray {
+    private final int[] data;
+    private final int[] dims;
+
+    public IntArray(int... dims) {
+        if (dims.length < 1) {
+            throw new IllegalArgumentException("array cannot have " + dims.length + " dimensions");
+        }
+        this.dims = dims;
+        int size = 1;
+        for (int dim : dims) {
+            size *= dim;
+        }
+        data = new int[size];
+    }
+
+    public int get(int... coords) {
+        if (coords.length < 1) {
+            throw new IllegalArgumentException("must supply at least one coordinate");
+        }
+        int index = 0;
+        if (coords.length > 1) {
+            for (int i = coords.length - 2; i >= 0; i--) {
+                index += coords[i] * dims[i + 1];
+            }
+        }
+
+        return data[index + coords[coords.length - 1]];
+    }
+
+    /**
+     * 'smart' use of varargs int: first values are the coordinates, last is the value itself
+     *
+     * @param coordsVal, all coordinates and the value to set
+     */
+    public void set(int... coordsVal) {
+        if (coordsVal.length < 2) {
+            throw new IllegalArgumentException("must supply at least one coordinate and a value to set");
+        }
+        int index = 0;
+        if (coordsVal.length > 2) {
+            for (int i = coordsVal.length - 3; i >= 0; i--) {
+                index += coordsVal[i] * dims[i + 1];
+            }
+        }
+
+        data[index + coordsVal[coordsVal.length - 2]] = coordsVal[coordsVal.length - 1];
+    }
+
+    int internalSize() {
+        return data.length;
+    }
+
+
+}
+
diff --git a/src/main/java/com/github/shautvast/multidim/JmhBenchmark.java b/src/main/java/com/github/shautvast/multidim/JmhBenchmark.java
new file mode 100644
index 0000000..e8cebb7
--- /dev/null
+++ b/src/main/java/com/github/shautvast/multidim/JmhBenchmark.java
@@ -0,0 +1,130 @@
+package com.github.shautvast.multidim;
+
+import org.openjdk.jmh.annotations.*;
+
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@Fork(value = 1)
+public class JmhBenchmark {
+
+    private static final int ROWS = 100;
+    private static final int COLS = 100;
+
+
+    @org.openjdk.jmh.annotations.State(Scope.Thread)
+    public static class State {
+        Int2dArray seqInt2DArray;
+        IntArray intArray;
+        int[][] ints;
+
+        @Setup(Level.Iteration)
+        public void doSetup() {
+            long seed = System.currentTimeMillis();
+            Random random = new Random(seed);
+            ints = new int[COLS][ROWS];
+            intArray = new IntArray(COLS, ROWS);
+            seqInt2DArray = new Int2dArray(COLS, ROWS);
+
+            for (int r = 0; r < ROWS; r++) {
+                for (int c = 0; c < COLS; c++) {
+                    int i = random.nextInt();
+                    intArray.set(r, c, i);
+                    seqInt2DArray.set(r, c, i);
+                }
+            }
+        }
+
+    }
+
+    //@Benchmark
+    public Int2dArray seq2DArraySetTDLR(State state) {
+        Int2dArray d2Array = new Int2dArray(ROWS, COLS);
+        for (int r = 0; r < ROWS; r++) {
+            for (int c = 0; c < COLS; c++) {
+                d2Array.set(r, c, r * c);
+            }
+        }
+        return d2Array;
+    }
+
+    //@Benchmark
+    public int[][] classicArraySet(State state) {
+        int[][] d2Array = new int[ROWS][COLS];
+        for (int r = 0; r < ROWS; r++) {
+            for (int c = 0; c < COLS; c++) {
+                d2Array[r][c] = r * c;
+            }
+        }
+        return d2Array;
+    }
+
+    @Benchmark
+    public int classicArrayGetTDLR(State state) {
+        int t = 0;
+        for (int r = 0; r < ROWS; r++) {
+            for (int c = 0; c < COLS; c++) {
+                t += state.ints[r][c];
+            }
+        }
+
+        return t;
+    }
+
+    @Benchmark
+    public int classicArrayGetLRTD(State state) {
+        int t = 0;
+        for (int c = 0; c < COLS; c++) {
+            for (int r = 0; r < ROWS; r++) {
+                t += state.ints[r][c];
+            }
+        }
+        return t;
+    }
+
+//    @Benchmark
+    public int seq2DArrayGetTDLR(State state) {
+        int t = 0;
+        for (int r = 0; r < ROWS; r++) {
+            for (int c = 0; c < COLS; c++) {
+                t += state.seqInt2DArray.get(r, c);
+            }
+        }
+        return t;
+    }
+
+    //@Benchmark
+    public int seq2DArrayGetLRTD(State state) {
+        int t = 0;
+        for (int r = 0; r < ROWS; r++) {
+            for (int c = 0; c < COLS; c++) {
+                t += state.seqInt2DArray.get(r, c);
+            }
+        }
+        return t;
+    }
+
+    //@Benchmark
+    public int seqMultArrayGetLRTD(State state) {
+        int t = 0xFFFFFFFF;
+        for (int c = 0; c < COLS; c++) {
+            for (int r = 0; r < ROWS; r++) {
+                t = state.intArray.get(r, c);
+            }
+        }
+        return t;
+    }
+
+    //@Benchmark
+    public int seqMultArrayGetTDLR(State state) {
+        int t = 0;
+        for (int r = 0; r < ROWS; r++) {
+            for (int c = 0; c < COLS; c++) {
+                t = state.intArray.get(r, c);
+            }
+        }
+        return t;
+    }
+}
\ No newline at end of file
diff --git a/src/test/java/com/github/shautvast/multidim/IntArrayTest.java b/src/test/java/com/github/shautvast/multidim/IntArrayTest.java
new file mode 100644
index 0000000..3108289
--- /dev/null
+++ b/src/test/java/com/github/shautvast/multidim/IntArrayTest.java
@@ -0,0 +1,28 @@
+package com.github.shautvast.multidim;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class IntArrayTest {
+    @Test
+    void test() {
+        IntArray intArray = new IntArray(2, 3, 5);
+        assertEquals(30, intArray.internalSize());
+        for (int i = 0; i < 2; i++) {
+            for (int j = 0; j < 3; j++) {
+                for (int k = 0; k < 5; k++) {
+                    intArray.set(i, j, k, 2 * 3 * i + 3 * j + k);
+                }
+            }
+        }
+
+        for (int i = 0; i < 2; i++) {
+            for (int j = 0; j < 3; j++) {
+                for (int k = 0; k < 5; k++) {
+                    assertEquals(2 * 3 * i, 3 * j + k, intArray.get(i, j, k));
+                }
+            }
+        }
+    }
+}