FootPrint.java

package old.keke;

import org.openjdk.jol.info.GraphLayout;

/*
last optimization - using short mask for booleans
 */
public class FootPrint {

    static final short IS_MALE = 0, IS_EXISTENT_USER = 1, IS_KNOWN_CUSTOMER = 2, IS_BANNED_USER = 3,IS_PREMIUM_USER = 4,
            IS_CACHED_USER = 5, IS_FOREIGN_CLIENT = 6, IS_EXTERNAL_USER = 7, IS_MASTER_CARD = 8;
    public static void main(String[] args) {
      /* converting all booleans  to short using mask
      short resultValue = convertToShort(true, false,true,
               false,false,true,true,true,false);
       boolean isMaleValue = convertToBoolean(resultValue, IS_MALE);
       boolean isBannedUserValue = convertToBoolean(resultValue, IS_BANNED_USER);

       System.out.println(resultValue);
       System.out.println(Integer.toBinaryString(resultValue));
       System.out.println(isMaleValue);
       System.out.println(isBannedUserValue);*/

        User user = new User(System.currentTimeMillis(), (short)13133, (short)10, (short)2331, (short) 229);

        System.out.println(GraphLayout.parseInstance(user).totalSize());

    }

    public static short convertToShort(boolean isMale, boolean isExistentUser, boolean isKnownCustomer, boolean isBannedUser,
                                       boolean isPremiumUser, boolean isCachedUser, boolean isForeignClient, boolean isExternalUser,
                                       boolean isMasterCard){
        short isMaleShort = (short) (isMale ? 1 : 0);
        short isExistentUserShort = (short) (isExistentUser ? 1 : 0);
        short isKnownCustomerShort = (short) (isKnownCustomer ? 1 : 0);
        short isBannedUserShort = (short) (isBannedUser ? 1 : 0);
        short isPremiumUserShort = (short) (isPremiumUser ? 1 : 0);
        short isCachedUserShort = (short) (isCachedUser ? 1 : 0);
        short isForeignClientShort = (short) (isForeignClient ? 1 : 0);
        short isExternalUserShort = (short) (isExternalUser ? 1 : 0);
        short isMasterCardShort = (short) (isMasterCard ? 1 : 0);

        return (short) (isMaleShort << IS_MALE | isExistentUserShort << IS_EXISTENT_USER | isKnownCustomerShort << IS_KNOWN_CUSTOMER
                |  isBannedUserShort << IS_BANNED_USER | isPremiumUserShort << IS_PREMIUM_USER | isCachedUserShort << IS_CACHED_USER
                | isForeignClientShort << IS_FOREIGN_CLIENT | isExternalUserShort << IS_EXTERNAL_USER | isMasterCardShort << IS_MASTER_CARD);
    }


    public static boolean convertToBoolean(short value, short flagPosition){
        return (value >> flagPosition & 1) == 1;
    }

    static class User {
        long dateOfBirth;
        short fixedSalary;
        short bonusPercent;
        short cardNumber;
        short allFlagsValues;

        public User(long dateOfBirth, short fixedSalary, short bonusPercent, short cardNumber, short allFlagsValues) {
            this.dateOfBirth = dateOfBirth;
            this.fixedSalary = fixedSalary;
            this.bonusPercent = bonusPercent;
            this.cardNumber = cardNumber;
            this.allFlagsValues = allFlagsValues;
        }


    }



    /* Third optimization using narrow types: 40 bytes
    static class User {
        long dateOfBirth;
        boolean isMale, isExistentUser, isKnownCustomer,
                isBannedUser, isPremiumUser,
                isCachedUser, isForeignUser;
        short fixedSalary;
        short bonusPercent;
        boolean isExternalUser;
        boolean isMaterCard;
        short cardNumber;

        public User(long dateOfBirth, boolean isMale, boolean isExistentUser, boolean isKnownCustomer, boolean isBannedUser, boolean isPremiumUser, boolean isCachedUser, boolean isForeignUser, short fixedSalary, short bonusPercent, boolean isExternalUser, boolean isMaterCard, short cardNumber) {
            this.dateOfBirth = dateOfBirth;
            this.isMale = isMale;
            this.isExistentUser = isExistentUser;
            this.isKnownCustomer = isKnownCustomer;
            this.isBannedUser = isBannedUser;
            this.isPremiumUser = isPremiumUser;
            this.isCachedUser = isCachedUser;
            this.isForeignUser = isForeignUser;
            this.fixedSalary = fixedSalary;
            this.bonusPercent = bonusPercent;
            this.isExternalUser = isExternalUser;
            this.isMaterCard = isMaterCard;
            this.cardNumber = cardNumber;
        }
    }
     */

/* Second optimization - moving all fields in one single class total size - 64 shorts
 public static void main(String[] args) {
        User user = new User(new Date(System.currentTimeMillis()), false, false, false,
                false, false, false, false, 1231, 12, false,
                true, 3333);

        System.out.println(GraphLayout.parseInstance(user).totalSize());
    }

    static class User {
        java.sql.Date dateOfBirth;
        boolean isMale, isExistentUser, isKnownCustomer,
                isBannedUser, isPremiumUser,
                isCachedUser, isForeignUser;
        int fixedSalary;
        int bonusPercent;
        boolean isExternalUser;
        boolean isMaterCard;
        int cardNumber;

        public User(Date dateOfBirth, boolean isMale, boolean isExistentUser, boolean isKnownCustomer, boolean isBannedUser, boolean isPremiumUser, boolean isCachedUser, boolean isForeignUser, int fixedSalary, int bonusPercent, boolean isExternalUser, boolean isMaterCard, int cardNumber) {
            this.dateOfBirth = dateOfBirth;
            this.isMale = isMale;
            this.isExistentUser = isExistentUser;
            this.isKnownCustomer = isKnownCustomer;
            this.isBannedUser = isBannedUser;
            this.isPremiumUser = isPremiumUser;
            this.isCachedUser = isCachedUser;
            this.isForeignUser = isForeignUser;
            this.fixedSalary = fixedSalary;
            this.bonusPercent = bonusPercent;
            this.isExternalUser = isExternalUser;
            this.isMaterCard = isMaterCard;
            this.cardNumber = cardNumber;
        }
    }
* */

/*
 first opimization - from wrappers to primitives total size 112
 public static void main(String[] args) {
        UserPaymentDetails userPaymentDetails = new UserPaymentDetails(true, 3333);
        UserSalary userSalary = new UserSalary(1231, 12, false, userPaymentDetails);
        User user = new User(new Date(System.currentTimeMillis()), false, false, false,
                false, false, false, false, userSalary);


        System.out.println(GraphLayout.parseInstance(userPaymentDetails).totalSize());
        System.out.println(GraphLayout.parseInstance(userSalary).totalSize());
        System.out.println(GraphLayout.parseInstance(user).totalSize());
}

    static class User {
        java.sql.Date dateOfBirth;
        boolean isMale, isExistentUser, isKnownCustomer,
                isBannedUser, isPremiumUser,
                isCachedUser, isForeignUser;
        UserSalary salary;

        public User(Date dateOfBirth, boolean isMale, boolean isExistentUser, boolean isKnownCustomer, boolean isBannedUser, boolean isPremiumUser, boolean isCachedUser, boolean isForeignUser, UserSalary salary) {
            this.dateOfBirth = dateOfBirth;
            this.isMale = isMale;
            this.isExistentUser = isExistentUser;
            this.isKnownCustomer = isKnownCustomer;
            this.isBannedUser = isBannedUser;
            this.isPremiumUser = isPremiumUser;
            this.isCachedUser = isCachedUser;
            this.isForeignUser = isForeignUser;
            this.salary = salary;
        }
    }

    static class UserSalary {
        int fixedSalary;
        int bonusPercent;
        boolean isExternalUser;
        UserPaymentDetails userDetails;

        public UserSalary(int fixedSalary, int bonusPercent, boolean isExternalUser, UserPaymentDetails userDetails) {
            this.fixedSalary = fixedSalary;
            this.bonusPercent = bonusPercent;
            this.isExternalUser = isExternalUser;
            this.userDetails = userDetails;
        }
    }

    static class UserPaymentDetails {
        boolean isMaterCard;
        int cardNumber;

        public UserPaymentDetails(boolean isMaterCard, int cardNumber) {
            this.isMaterCard = isMaterCard;
            this.cardNumber = cardNumber;
        }
    }


 */

/* Initial version: total size: 208
package old.keke;

import org.openjdk.jol.info.ClassLayout;
import org.openjdk.jol.info.GraphLayout;
import org.openjdk.jol.vm.VM;

import java.sql.Date;

public class FootPrint {

    public static void main(String[] args) {
        UserPaymentDetails userPaymentDetails = new UserPaymentDetails(true, 3333);
        UserSalary userSalary = new UserSalary(1231, 12, false, userPaymentDetails);
        User user = new User(new Date(System.currentTimeMillis()), false, false, false,
                false, false, false, false, userSalary);


        System.out.println(GraphLayout.parseInstance(userPaymentDetails).totalSize());
        System.out.println(GraphLayout.parseInstance(userSalary).totalSize());
        System.out.println(GraphLayout.parseInstance(user).totalSize());
}

    static class User {
        java.sql.Date dateOfBirth;
        Boolean isMale, isExistentUser, isKnownCustomer,
                isBannedUser, isPremiumUser, isCachedUser, isForeignUser;
        UserSalary salary;

        public User(Date dateOfBirth, Boolean isMale, Boolean isExistentUser, Boolean isKnownCustomer, Boolean isBannedUser, Boolean isPremiumUser, Boolean isCachedUser, Boolean isForeignUser, UserSalary salary) {
            this.dateOfBirth = dateOfBirth;
            this.isMale = isMale;
            this.isExistentUser = isExistentUser;
            this.isKnownCustomer = isKnownCustomer;
            this.isBannedUser = isBannedUser;
            this.isPremiumUser = isPremiumUser;
            this.isCachedUser = isCachedUser;
            this.isForeignUser = isForeignUser;
            this.salary = salary;
        }
    }

    static class UserSalary {
        Integer fixedSalary;
        Integer bonusPercent;
        Boolean isExternalUser;
        UserPaymentDetails userDetails;

        public UserSalary(Integer fixedSalary, Integer bonusPercent, Boolean isExternalUser, UserPaymentDetails userDetails) {
            this.fixedSalary = fixedSalary;
            this.bonusPercent = bonusPercent;
            this.isExternalUser = isExternalUser;
            this.userDetails = userDetails;
        }
    }

    static class UserPaymentDetails {
        Boolean isMaterCard;
        Integer cardNumber;

        public UserPaymentDetails(Boolean isMaterCard, Integer cardNumber) {
            this.isMaterCard = isMaterCard;
            this.cardNumber = cardNumber;
        }
    }
}

* */
}