ru.curs.lyra.kernel.grid

Class KeyInterpolator

java.lang.Object

ru.curs.lyra.kernel.grid.KeyInterpolator

public class KeyInterpolator
extends Object

Кусочно-линейная аппроксимация распределения значений первичного ключа.

Constructor Summary

Constructors

Constructor and Description
KeyInterpolator(BigInteger minOrd, BigInteger maxOrd, int count, boolean descending)

Method Summary

Modifier and Type	Method and Description
int	getApproximateCount() Returns an (approximate) records count.
int	getApproximatePosition(BigInteger key) Returns an (approximate) position of a key in a set using inverse interpolation.
int	getClosestPosition(int count) The closest known position to to the given one.
BigInteger	getExactPoint(int count) Exact (not approximated) point or null if no such point exist in approximator.
BigInteger	getLeastAccurateValue() Gets the value that corresponds to the center of the biggest gap in this interpolation table.
BigInteger	getPoint(int count) Примерное значение первичного ключа по данному номеру.
int	getPointsCount() Количество имеющихся точек в таблице.
void	resetToEmptyTable() Resets the interpolator when all records are deleted.
void	setPoint(BigInteger ord, int count) Установка соответствия номера записи значению первичного ключа.

Methods inherited from class java.lang.Object

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

Constructor Detail

KeyInterpolator

public KeyInterpolator(BigInteger minOrd,
                       BigInteger maxOrd,
                       int count,
                       boolean descending)

Method Detail

setPoint

public void setPoint(BigInteger ord,
                     int count)

Установка соответствия номера записи значению первичного ключа.

Parameters:

ord - Порядковое значение первичного ключа.

count - Номер записи.

getExactPoint

public BigInteger getExactPoint(int count)

Exact (not approximated) point or null if no such point exist in approximator.

Parameters:

count - Record's number.

getClosestPosition

public int getClosestPosition(int count)

The closest known position to to the given one.

Parameters:

count - The ordinal number of record.

getPoint

public BigInteger getPoint(int count)

Примерное значение первичного ключа по данному номеру.

Parameters:

count - Номер записи.

getPointsCount

public int getPointsCount()

Количество имеющихся точек в таблице.

getApproximateCount

public int getApproximateCount()

Returns an (approximate) records count.

getApproximatePosition

public int getApproximatePosition(BigInteger key)

Returns an (approximate) position of a key in a set using inverse interpolation.

Parameters:

key - Key ordinal value.

getLeastAccurateValue

public BigInteger getLeastAccurateValue()

Gets the value that corresponds to the center of the biggest gap in this interpolation table.

Returns null if there is no gap big enough.

resetToEmptyTable

public void resetToEmptyTable()

Resets the interpolator when all records are deleted.