com.healthmarketscience.jackcess.impl

Class NullMask

java.lang.Object

com.healthmarketscience.jackcess.impl.NullMask

public class NullMask
extends java.lang.Object

Bitmask that indicates whether or not each column in a row is null. Also holds values of boolean columns.

Field Summary

Fields

Modifier and Type	Field and Description
private int	_columnCount num row columns
private byte[]	_mask The actual bitmask

Constructor Summary

Constructors

Constructor and Description
NullMask(int columnCount)

Method Summary

Modifier and Type	Method and Description
private static byte	bitMask(int columnNumber)
private static int	byteIndex(int columnNumber)
int	byteSize()
boolean	isNull(ColumnImpl column)
void	markNotNull(ColumnImpl column) Indicate that the column with the given number is not null (or a boolean value is true).
void	read(java.nio.ByteBuffer buffer) Read a mask in from a buffer
void	write(java.nio.ByteBuffer buffer) Write a mask to a buffer

Methods inherited from class java.lang.Object

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

Field Detail

_columnCount

private final int _columnCount

num row columns

_mask

private final byte[] _mask

The actual bitmask

Constructor Detail

NullMask

public NullMask(int columnCount)

Parameters:

columnCount - Number of columns in the row that this mask will be used for

Method Detail

read

public void read(java.nio.ByteBuffer buffer)

Read a mask in from a buffer

write

public void write(java.nio.ByteBuffer buffer)

Write a mask to a buffer

isNull

public boolean isNull(ColumnImpl column)

Parameters:

column - column to test for null

Returns:

Whether or not the value for that column is null. For boolean columns, returns the actual value of the column (where non-null == true)

markNotNull

public void markNotNull(ColumnImpl column)

Indicate that the column with the given number is not null (or a boolean value is true).

Parameters:

column - column to be marked non-null

byteSize

public int byteSize()

Returns:

Size in bytes of this mask

byteIndex

private static int byteIndex(int columnNumber)

bitMask

private static byte bitMask(int columnNumber)