SkuMemTest

SkuMemTest.java

import java.util.Map;
import java.util.Objects;
import java.util.Random;
import java.util.Scanner;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.stream.Collectors;
import java.util.stream.Stream;

/**
 * @author Alexander Kramarev (pochemuto@yandex-team.ru)
 * @date 19.07.2017
 */
public class SkuMemTest {
    private static final int SIZE = 1_000_000;
    private static final int PARAMS_COUNT = 6;

    private static final Random RANDOM = new Random();
    private static final int SKU_LENGTH = 20;
    private ConcurrentMap<Key, String> map;

    public static void main(String... args) {
        SkuMemTest t = new SkuMemTest();
        t.perform();
    }

    private void perform() {
        map = new ConcurrentHashMap<>(SIZE);
        System.out.println("generating...");
        Stream.generate(this::randomKey)
                .limit(SIZE)
                .forEach(k -> map.put(k, randomSku()));
        System.out.println(map.size() + " done.");
        System.out.println("Press enter to exit...");
        new Scanner(System.in).next();
        logSize(map);
    }

    private void logSize(Map<Key, String> map) {
        System.out.println("size: " + map.size());
    }


    @SuppressWarnings("CheckStyle")
    private String randomSku() {
        return RANDOM.ints(SKU_LENGTH).map(i -> i % 10)
                .mapToObj(String::valueOf)
                .collect(Collectors.joining());
    }

    private Key randomKey() {
        Set<ParamValue> values = Stream.generate(this::randomValue)
                .limit(PARAMS_COUNT)
                .collect(Collectors.toSet());

        return new Key(RANDOM.nextLong(), values);
    }

    private ParamValue randomValue() {
        return new ParamValue(
                RANDOM.nextLong(),
                RANDOM.nextLong(),
                RANDOM.nextBoolean(),
                RANDOM.nextDouble()
        );
    }
}

class Key {
    private final long modelId;
    private final Set<ParamValue> values;

    Key(long modelId, Set<ParamValue> values) {
        this.modelId = modelId;
        this.values = values;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Key key = (Key) o;
        return modelId == key.modelId &&
                Objects.equals(values, key.values);
    }

    @Override
    public int hashCode() {
        return Objects.hash(modelId, values);
    }
}

class ParamValue {
    private final long paramId;
    private final long valueId;
    private final boolean booleanValue;
    private final double numberValue;

    ParamValue(long paramId, long valueId, boolean booleanValue, double numberValue) {
        this.paramId = paramId;
        this.valueId = valueId;
        this.booleanValue = booleanValue;
        this.numberValue = numberValue;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        ParamValue that = (ParamValue) o;
        return paramId == that.paramId &&
                valueId == that.valueId &&
                booleanValue == that.booleanValue &&
                Double.compare(that.numberValue, numberValue) == 0;
    }

    @Override
    public int hashCode() {
        return Objects.hash(paramId, valueId, booleanValue, numberValue);
    }
}