Package org.apache.iotdb.tsfile.read.common.block.column

Class NullColumn

java.lang.Object

org.apache.iotdb.tsfile.read.common.block.column.NullColumn

All Implemented Interfaces:

Column

public class NullColumn
extends java.lang.Object
implements Column

This column is used to represent columns that only contain null values. But its positionCount has to be consistent with corresponding valueColumn.

Constructor Summary

Constructors

Constructor	Description
NullColumn(int positionCount)

Method Summary

Modifier and Type	Method	Description
static Column	create(TSDataType dataType, int positionCount)
TSDataType	getDataType()	Get the data type.
ColumnEncoding	getEncoding()	Get the encoding for this column.
int	getInstanceSize()
int	getPositionCount()	Returns the number of positions in this block.
Column	getRegion(int positionOffset, int length)	Returns a column starting at the specified position and extends for the specified length.
long	getRetainedSizeInBytes()	Returns the retained size of this column in memory, including over-allocations.
boolean[]	isNull()	Returns the array to determine whether each position of the column is null or not.
boolean	isNull(int position)	Is the specified position null?
boolean	mayHaveNull()	Is it possible the column may have a null value? If false, the column cannot contain a null, but if true, the column may or may not have a null.
void	reverse()	reverse the column
Column	subColumn(int fromIndex)	This method will create a temporary view of origin column, which will reuse the array of column but with different array offset.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.iotdb.tsfile.read.common.block.column.Column

getBinaries, getBinary, getBoolean, getBooleans, getDouble, getDoubles, getFloat, getFloats, getInt, getInts, getLong, getLongs, getObject, getObjects, getTsPrimitiveType

Constructor Detail

NullColumn

public NullColumn(int positionCount)

Method Detail

getDataType

public TSDataType getDataType()

Description copied from interface: Column

Get the data type.

Specified by:

getDataType in interface Column

getEncoding

public ColumnEncoding getEncoding()

Description copied from interface: Column

Get the encoding for this column.

Specified by:

getEncoding in interface Column

mayHaveNull

public boolean mayHaveNull()

Description copied from interface: Column

Is it possible the column may have a null value? If false, the column cannot contain a null, but if true, the column may or may not have a null.

Specified by:

mayHaveNull in interface Column

isNull

public boolean isNull(int position)

Description copied from interface: Column

Is the specified position null?

Specified by:

isNull in interface Column

isNull

public boolean[] isNull()

Description copied from interface: Column

Returns the array to determine whether each position of the column is null or not.

Specified by:

isNull in interface Column

getPositionCount

public int getPositionCount()

Description copied from interface: Column

Returns the number of positions in this block.

Specified by:

getPositionCount in interface Column

getRetainedSizeInBytes

public long getRetainedSizeInBytes()

Description copied from interface: Column

Returns the retained size of this column in memory, including over-allocations. This method is called from the inner most execution loop and must be fast.

Specified by:

getRetainedSizeInBytes in interface Column

getRegion

public Column getRegion(int positionOffset,
                        int length)

Description copied from interface: Column

Returns a column starting at the specified position and extends for the specified length. The specified region must be entirely contained within this column.

The region can be a view over this column. If this column is released, the region column may also be released. If the region column is released, this block may also be released.

Specified by:

getRegion in interface Column

subColumn

public Column subColumn(int fromIndex)

Description copied from interface: Column

This method will create a temporary view of origin column, which will reuse the array of column but with different array offset.

Specified by:

subColumn in interface Column

reverse

public void reverse()

Description copied from interface: Column

reverse the column

Specified by:

reverse in interface Column

create

public static Column create(TSDataType dataType,
                            int positionCount)

getInstanceSize

public int getInstanceSize()

Specified by:

getInstanceSize in interface Column