Introduced jmh benchmarking (eugenp#2549)

core-java/pom.xml

@@ -201,6 +201,16 @@
             <artifactId>vavr</artifactId>
             <version>${vavr.version}</version>
 	    </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>1.19</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>1.19</version>
+        </dependency>
     </dependencies>
 
     <build>

core-java/src/main/java/com/baeldung/numberofdigits/Benchmarking.java

@@ -1,131 +1,67 @@
 package com.baeldung.numberofdigits;
 
-import static com.baeldung.designpatterns.util.LogerUtil.LOG;;
-
-public class Benchmarking {;
-
-    private static final int LOWER_BOUND = 1;
-    private static final int UPPER_BOUND = 999999999;
-
-
-    public static void main(String[] args) {
-        LOG.info("Testing all methods...");
-
-        long length = test_stringBasedSolution();
-        LOG.info("String Based Solution : " + length);
-
-        length = test_logarithmicApproach();
-        LOG.info("Logarithmic Approach : " + length);
-
-        length = test_repeatedMultiplication();
-        LOG.info("Repeated Multiplication : " + length);
-
-        length = test_shiftOperators();
-        LOG.info("Shift Operators : " + length);
-
-        length = test_dividingWithPowersOf2();
-        LOG.info("Dividing with Powers of 2 : " + length);
-
-        length = test_divideAndConquer();
-        LOG.info("Divide And Conquer : " + length);
-
+import java.io.IOException;
+import java.util.concurrent.TimeUnit;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.runner.RunnerException;
+
+public class Benchmarking {
+    public static void main(String[] args) throws RunnerException, IOException {
+        org.openjdk.jmh.Main.main(args);
     }
 
-    private static long test_stringBasedSolution() {
-
-        long startTime, stopTime, elapsedTime;
-        startTime = System.currentTimeMillis();
-
-        int total = 0;
-        for (int i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
-            total += NumberOfDigits.stringBasedSolution(i);
-        }
-
-        stopTime = System.currentTimeMillis();
-        elapsedTime = stopTime - startTime;
-
-        return elapsedTime;
+    @State(Scope.Thread)
+    public static class ExecutionPlan {
+        public int number = Integer.MAX_VALUE;
+        public int length = 0;
+        public NumberOfDigits numberOfDigits= new NumberOfDigits();
     }
-
-    private static long test_logarithmicApproach() {
-
-        long startTime, stopTime, elapsedTime;
-        startTime = System.currentTimeMillis();
-
-        int total = 0;
-        for (int i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
-            total += NumberOfDigits.logarithmicApproach(i);
-        }
-
-        stopTime = System.currentTimeMillis();
-        elapsedTime = stopTime - startTime;
-
-        return elapsedTime;
-    }
-
-    private static long test_repeatedMultiplication() {
-
-        long startTime, stopTime, elapsedTime;
-        startTime = System.currentTimeMillis();
-
-        int total = 0;
-        for (int i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
-            total += NumberOfDigits.repeatedMultiplication(i);
-        }
-
-        stopTime = System.currentTimeMillis();
-        elapsedTime = stopTime - startTime;
-
-        return elapsedTime;
+
+    @Benchmark 
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    public void stringBasedSolution(ExecutionPlan plan) {
+        plan.length = plan.numberOfDigits.stringBasedSolution(plan.number);
     }
-
-    private static long test_shiftOperators() {
-
-        long startTime, stopTime, elapsedTime;
-        startTime = System.currentTimeMillis();
-
-        int total = 0;
-        for (int i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
-            total += NumberOfDigits.shiftOperators(i);
-        }
-
-        stopTime = System.currentTimeMillis();
-        elapsedTime = stopTime - startTime;
-
-        return elapsedTime;
+
+    @Benchmark 
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    public void logarithmicApproach(ExecutionPlan plan) {
+        plan.length = plan.numberOfDigits.logarithmicApproach(plan.number);
     }
-
-    private static long test_dividingWithPowersOf2() {
-
-        long startTime, stopTime, elapsedTime;
-        startTime = System.currentTimeMillis();
-
-        int total = 0;
-        for (int i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
-            total += NumberOfDigits.dividingWithPowersOf2(i);
-        }
-
-        stopTime = System.currentTimeMillis();
-        elapsedTime = stopTime - startTime;
-
-        return elapsedTime;
+
+    @Benchmark 
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    public void repeatedMultiplication(ExecutionPlan plan) {
+        plan.length = plan.numberOfDigits.repeatedMultiplication(plan.number);
     }
-
-    private static long test_divideAndConquer() {
-
-        long startTime, stopTime, elapsedTime;
-        startTime = System.currentTimeMillis();
-
-        int total = 0;
-        for (int i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
-            total += NumberOfDigits.divideAndConquer(i);
-        }
-
-        stopTime = System.currentTimeMillis();
-        elapsedTime = stopTime - startTime;
-
-        return elapsedTime;
+
+    @Benchmark 
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    public void shiftOperators(ExecutionPlan plan) {
+        plan.length = plan.numberOfDigits.shiftOperators(plan.number);
     }
 
+    @Benchmark 
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    public void dividingWithPowersOf2(ExecutionPlan plan) {
+        plan.length = plan.numberOfDigits.dividingWithPowersOf2(plan.number);
+    }
 
+    @Benchmark 
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    public void divideAndConquer(ExecutionPlan plan) {
+        plan.length = plan.numberOfDigits.divideAndConquer(plan.number);
+    }
 }

core-java/src/main/java/com/baeldung/numberofdigits/NumberOfDigits.java

@@ -1,17 +1,17 @@
 package com.baeldung.numberofdigits;
 
 public class NumberOfDigits {
-    public static int stringBasedSolution(int number) {
+    public int stringBasedSolution(int number) {
         int length = String.valueOf(number).length();
         return length;
     }
 
-    public static int logarithmicApproach(int number) {
+    public int logarithmicApproach(int number) {
         int length = (int) Math.log10(number) + 1;
         return length;
     }
 
-    public static int repeatedMultiplication(int number) {
+    public int repeatedMultiplication(int number) {
         int length = 0;
         long temp = 1;
         while(temp <= number) {
@@ -21,7 +21,7 @@ public static int repeatedMultiplication(int number) {
         return length;
     }
 
-    public static int shiftOperators(int number) {
+    public int shiftOperators(int number) {
         int length = 0;
         long temp = 1;
         while(temp <= number) {
@@ -31,7 +31,7 @@ public static int shiftOperators(int number) {
         return length;
     }
 
-    public static int dividingWithPowersOf2(int number) {
+    public int dividingWithPowersOf2(int number) {
         int length = 1;
         if (number >= 100000000) {
             length += 8;
@@ -51,7 +51,7 @@ public static int dividingWithPowersOf2(int number) {
         return length;
     }
 
-    public static int divideAndConquer(int number) {
+    public int divideAndConquer(int number) {
         if (number < 100000){
             // 5 digits or less
             if (number < 100){

core-java/src/main/java/com/baeldung/numberofdigits/NumberOfDigitsDriver.java

@@ -1,27 +1,33 @@
-package com.baeldung.numberofdigits;
-
-import static com.baeldung.designpatterns.util.LogerUtil.LOG;
-
-public class NumberOfDigitsDriver {
-    public static void main(String[] args) {
-        LOG.info("Testing all methods...");
-
-        long length = NumberOfDigits.stringBasedSolution(602);
-        LOG.info("String Based Solution : " + length);
-
-        length = NumberOfDigits.logarithmicApproach(602);
-        LOG.info("Logarithmic Approach : " + length);
-
-        length = NumberOfDigits.repeatedMultiplication(602);
-        LOG.info("Repeated Multiplication : " + length);
-
-        length = NumberOfDigits.shiftOperators(602);
-        LOG.info("Shift Operators : " + length);
-
-        length = NumberOfDigits.dividingWithPowersOf2(602);
-        LOG.info("Dividing with Powers of 2 : " + length);
-
-        length = NumberOfDigits.divideAndConquer(602);
-        LOG.info("Divide And Conquer : " + length);
-    }
-}
+package com.baeldung.numberofdigits;
+
+import static com.baeldung.designpatterns.util.LogerUtil.LOG;
+
+public class NumberOfDigitsDriver {
+    private static NumberOfDigits numberOfDigits;
+
+    static {
+        numberOfDigits = new NumberOfDigits();
+    }
+
+    public static void main(String[] args) {
+        LOG.info("Testing all methods...");
+
+        long length = numberOfDigits.stringBasedSolution(602);
+        LOG.info("String Based Solution : " + length);
+
+        length = numberOfDigits.logarithmicApproach(602);
+        LOG.info("Logarithmic Approach : " + length);
+
+        length = numberOfDigits.repeatedMultiplication(602);
+        LOG.info("Repeated Multiplication : " + length);
+
+        length = numberOfDigits.shiftOperators(602);
+        LOG.info("Shift Operators : " + length);
+
+        length = numberOfDigits.dividingWithPowersOf2(602);
+        LOG.info("Dividing with Powers of 2 : " + length);
+
+        length = numberOfDigits.divideAndConquer(602);
+        LOG.info("Divide And Conquer : " + length);
+    }
+}

core-java/src/test/java/com/baeldung/numberofdigits/NumberOfDigitsIntegrationTest.java

@@ -9,7 +9,13 @@
 
 @RunWith(Theories.class)
 public class NumberOfDigitsIntegrationTest {
-
+
+    private static NumberOfDigits numberOfDigits;
+
+    static {
+        numberOfDigits = new NumberOfDigits();
+    }
+
     @DataPoints
     public static int[][] lowestIntegers()
     {
@@ -64,37 +70,37 @@ public static int[][] randomIntegers()
     @Theory
     public void givenDataPoints_whenStringBasedSolutionInvoked_thenAllPointsMatch(final int[] entry) {
         Assume.assumeTrue(entry[0] > 0 && entry[1] > 0);
-        Assert.assertEquals(entry[0], NumberOfDigits.stringBasedSolution(entry[1]));
+        Assert.assertEquals(entry[0], numberOfDigits.stringBasedSolution(entry[1]));
     }
 
     @Theory
     public void givenDataPoints_whenLogarithmicApproachInvoked_thenAllPointsMatch(final int[] entry) {
         Assume.assumeTrue(entry[0] > 0 && entry[1] > 0);
-        Assert.assertEquals(entry[0], NumberOfDigits.logarithmicApproach(entry[1]));
+        Assert.assertEquals(entry[0], numberOfDigits.logarithmicApproach(entry[1]));
     }
 
     @Theory
     public void givenDataPoints_whenRepeatedMultiplicationInvoked_thenAllPointsMatch(final int[] entry) {
         Assume.assumeTrue(entry[0] > 0 && entry[1] > 0);
-        Assert.assertEquals(entry[0], NumberOfDigits.repeatedMultiplication(entry[1]));
+        Assert.assertEquals(entry[0], numberOfDigits.repeatedMultiplication(entry[1]));
     }
 
     @Theory
     public void givenDataPoints_whenShiftOperatorsInvoked_thenAllPointsMatch(final int[] entry) {
         Assume.assumeTrue(entry[0] > 0 && entry[1] > 0);
-        Assert.assertEquals(entry[0], NumberOfDigits.shiftOperators(entry[1]));
+        Assert.assertEquals(entry[0], numberOfDigits.shiftOperators(entry[1]));
     }
 
     @Theory
     public void givenDataPoints_whenDividingWithPowersOf2Invoked_thenAllPointsMatch(final int[] entry) {
         Assume.assumeTrue(entry[0] > 0 && entry[1] > 0);
-        Assert.assertEquals(entry[0], NumberOfDigits.dividingWithPowersOf2(entry[1]));
+        Assert.assertEquals(entry[0], numberOfDigits.dividingWithPowersOf2(entry[1]));
     }
 
     @Theory
     public void givenDataPoints_whenDivideAndConquerInvoked_thenAllPointsMatch(final int[] entry) {
         Assume.assumeTrue(entry[0] > 0 && entry[1] > 0);
-        Assert.assertEquals(entry[0], NumberOfDigits.divideAndConquer(entry[1]));
+        Assert.assertEquals(entry[0], numberOfDigits.divideAndConquer(entry[1]));
     }
 
 }