galaxy-platform-algorithm-sketches/src/test/java/org/HdrHistogram/HistogramSketchTest.java

package org.HdrHistogram;

import org.junit.Test;

import java.nio.ByteBuffer;
import java.util.concurrent.ThreadLocalRandom;

public class HistogramSketchTest {
    String line = "###################";

    @Test
    public void testArrayHistogram() {
        ArrayHistogram histogram = new ArrayHistogram(1);
        System.out.println(histogram.describe());
        for (int i = 0; i < 10000; i++) {
            histogram.recordValue(i);
        }
        System.out.println(histogram.describe());
        for (Percentile percentile : histogram.percentileList(5)) {
            System.out.println(percentile);
        }
        System.out.println(line);
        histogram = new ArrayHistogram(1);
        for (int i = 0; i < 10000; i++) {
            histogram.recordValue(ThreadLocalRandom.current().nextLong(100000));
        }
        System.out.println(histogram.describe());
        for (Percentile percentile : histogram.percentileList(5)) {
            System.out.println(percentile);
        }
    }

    @Test
    public void testDirectArrayHistogram() {
        ByteBuffer byteBuffer = ByteBuffer.allocate(DirectArrayHistogram.getUpdatableSerializationBytes(1, 100000, 1));
        DirectArrayHistogram histogram = new DirectArrayHistogram(1, 100000, 1,
                byteBuffer);
        System.out.println(histogram.describe());
        for (int i = 0; i < 10000; i++) {
            histogram.recordValue(i);
        }
        System.out.println(histogram.describe());
        for (Percentile percentile : histogram.percentileList(5)) {
            System.out.println(percentile);
        }
        System.out.println(line);
        histogram.resetByteBuffer(ByteBuffer.allocate(DirectArrayHistogram.getUpdatableSerializationBytes(1, 100000, 1)));
        histogram.reset();
        for (int i = 0; i < 10000; i++) {
            histogram.recordValue(ThreadLocalRandom.current().nextLong(100000));
        }
        System.out.println(histogram.describe());
        for (Percentile percentile : histogram.percentileList(5)) {
            System.out.println(percentile);
        }
    }

    @Test
    public void testCopy() {
        ArrayHistogram histogram1 = new ArrayHistogram(1);
        ByteBuffer byteBuffer = ByteBuffer.allocate(DirectArrayHistogram.getUpdatableSerializationBytes(1, 100000, 1));
        DirectArrayHistogram histogram2 = new DirectArrayHistogram(1, 100000, 1,
                byteBuffer);
        for (int i = 0; i < 10000; i++) {
            histogram1.recordValue(i);
            histogram2.recordValue(i);
        }

        ArrayHistogram copy1 = histogram1.copy();
        ArrayHistogram copy2 = histogram2.copy();

        System.out.println(histogram1.describe());
        System.out.println(histogram2.describe());
        System.out.println(line);

        System.out.println(copy1.describe());
        System.out.println(copy2.describe());
    }

    @Test
    public void testArrayHistogramMerge() {
        ArrayHistogram histogram1 = new ArrayHistogram(1);
        for (int i = 0; i < 1000; i++) {
            histogram1.recordValue(i);
        }
        byte[] bytes1 = histogram1.toBytes();

        DirectMapHistogram directHistogram = DirectMapHistogram.wrapBytes(bytes1);
        ArrayHistogram histogram2 = new ArrayHistogram(1);
        histogram2.merge(directHistogram);
        System.out.println(histogram2.describe());
    }

    @Test
    public void testDirectArrayHistogramMerge() {
        ArrayHistogram histogram1 = new ArrayHistogram(1);
        int updatableSerializationBytes = DirectArrayHistogram.getUpdatableSerializationBytes(1, 100000, 1);
        DirectArrayHistogram histogram2 = new DirectArrayHistogram(1, 100000, 1, ByteBuffer.allocate(updatableSerializationBytes));
        for (int i = 0; i < 10000; i++) {
            histogram1.recordValue(i);
            histogram2.recordValue(i);
        }
        byte[] bytes1 = histogram1.toBytes();
        byte[] bytes2 = histogram2.toBytes();

        DirectArrayHistogram histogram = new DirectArrayHistogram(1, 100000, 1, ByteBuffer.allocate(updatableSerializationBytes));
        histogram.merge(DirectMapHistogram.wrapBytes(bytes1));
        histogram.merge(DirectMapHistogram.wrapBytes(bytes2));
        System.out.println(histogram.describe());
        for (Percentile percentile : histogram.percentileList(5)) {
            System.out.println(percentile);
        }
    }
}