org.jscsi.target.util

Class SerialArithmeticNumber

java.lang.Object

org.jscsi.target.util.SerialArithmeticNumber

public final class SerialArithmeticNumber
extends Object

A class for serial number arithmetics, as defined in [RFC 1982], with SERIAL_BITS = 32.

Unlike the original algorithm, this implementation is based on unsigned subtraction, resolving the issue of undefined comparisons, however introducing one additional oddity - each member of a pair of serial numbers with a wrapped distance of 2^(SERIAL_BITS - 1) will be considered less than (and greater than) the other one.

Author:

Andreas Ergenzinger

Constructor Summary

Constructors

Constructor and Description
SerialArithmeticNumber() Creates a new SerialArithmeticNumber with a starting value of zero.
SerialArithmeticNumber(int value) Creates a new SerialArithmeticNumber with the specified starting value.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(int serialArithmeticNumber) Returns true if the parameter matches the value and false if it does not.
int	getValue() Returns the SerialArithmeticNumber's value.
boolean	greaterThan(int serialArithmeticNumber) Returns true if the parameter is greater than the value in serial number arithmetics and false if it is not.
void	increment() Increments the SerialArithmeticNumber's value by one.
boolean	lessThan(int serialArithmeticNumber) Returns true if the parameter is less than the value in serial number arithmetics and false if it is not.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SerialArithmeticNumber

public SerialArithmeticNumber()

Creates a new SerialArithmeticNumber with a starting value of zero.

SerialArithmeticNumber

public SerialArithmeticNumber(int value)

Creates a new SerialArithmeticNumber with the specified starting value.

Parameters:

value - the initial value

Method Detail

increment

public void increment()

Increments the SerialArithmeticNumber's value by one.

equals

public boolean equals(int serialArithmeticNumber)

Returns true if the parameter matches the value and false if it does not.

Parameters:

serialArithmeticNumber - the serial arithmetic number to match

Returns:

true if the parameter matches the value and false if it does not

lessThan

public boolean lessThan(int serialArithmeticNumber)

Returns true if the parameter is less than the value in serial number arithmetics and false if it is not.

Parameters:

serialArithmeticNumber - the serial arithmetic number to match

Returns:

true if the parameter is less than the value in serial number arithmetics and false if it is not

greaterThan

public boolean greaterThan(int serialArithmeticNumber)

Returns true if the parameter is greater than the value in serial number arithmetics and false if it is not.

Parameters:

serialArithmeticNumber - the serial arithmetic number to match

Returns:

true if the parameter is greater than the value in serial number arithmetics and false if it is not

getValue

public int getValue()

Returns the SerialArithmeticNumber's value.

Returns:

the value