mondrian.rolap.agg

Class SparseSegmentDataset

java.lang.Object

mondrian.rolap.agg.SparseSegmentDataset

All Implemented Interfaces:

Iterable<Map.Entry<CellKey,Object>>, SegmentDataset

 class SparseSegmentDataset
extends Object
implements SegmentDataset

A SparseSegmentDataset is a means of storing segment values which is suitable when few of the combinations of keys have a value present.

The storage requirements are as follows. Key is 1 word for each dimension. Hashtable entry is 3 words. Value is 1 word. Total space is (4 + d) * v. (May also need hash table to ensure that values are only stored once.)

NOTE: This class is not synchronized.

Since:

21 March, 2002

Author:

jhyde

Constructor Summary

Constructors

Constructor and Description
SparseSegmentDataset() Creates an empty SparseSegmentDataset.
SparseSegmentDataset(Map<CellKey,Object> values) Creates a SparseSegmentDataset with a given value map.

Method Summary

Methods

Modifier and Type	Method and Description
SegmentBody	createSegmentBody(List<Pair<SortedSet<Comparable>,Boolean>> axes) Return an immutable, final and serializable implementation of a SegmentBody in order to cache this dataset.
boolean	exists(CellKey pos) Returns whether there is a value at a given coordinate.
double	getBytes() Returns the number of bytes occupied by this dataset.
double	getDouble(CellKey pos) Returns the value at a given coordinate, as a double.
int	getInt(CellKey pos) Returns the value at a given coordinate, as an int.
Object	getObject(CellKey pos) Returns the value at a given coordinate, as an Object.
SqlStatement.Type	getType() Returns the SQL type of the data contained in this dataset.
boolean	isNull(CellKey pos) Returns whether the cell at a given coordinate is null.
Iterator<Map.Entry<CellKey,Object>>	iterator()
void	populateFrom(int[] pos, SegmentDataset data, CellKey key)
void	populateFrom(int[] pos, SegmentLoader.RowList rowList, int column) Sets the value a given ordinal.
void	put(CellKey key, Object value)

Methods inherited from class java.lang.Object

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

Constructor Detail

SparseSegmentDataset

SparseSegmentDataset()

Creates an empty SparseSegmentDataset.

SparseSegmentDataset

SparseSegmentDataset(Map<CellKey,Object> values)

Creates a SparseSegmentDataset with a given value map. The map is not copied; a reference to the map is retained inside the dataset, and therefore the contents of the dataset will change if the map is modified.

Parameters:

values - Value map

Method Detail

getObject

public Object getObject(CellKey pos)

Description copied from interface: SegmentDataset

Returns the value at a given coordinate, as an Object.

Specified by:

getObject in interface SegmentDataset

Parameters:

pos - Coordinate position

Returns:

Value

isNull

public boolean isNull(CellKey pos)

Description copied from interface: SegmentDataset

Returns whether the cell at a given coordinate is null.

Specified by:

isNull in interface SegmentDataset

Parameters:

pos - Coordinate position

Returns:

Whether cell value is null

getInt

public int getInt(CellKey pos)

Description copied from interface: SegmentDataset

Returns the value at a given coordinate, as an int.

Specified by:

getInt in interface SegmentDataset

Parameters:

pos - Coordinate position

Returns:

Value

getDouble

public double getDouble(CellKey pos)

Description copied from interface: SegmentDataset

Returns the value at a given coordinate, as a double.

Specified by:

getDouble in interface SegmentDataset

Parameters:

pos - Coordinate position

Returns:

Value

exists

public boolean exists(CellKey pos)

Description copied from interface: SegmentDataset

Returns whether there is a value at a given coordinate.

Specified by:

exists in interface SegmentDataset

Parameters:

pos - Coordinate position

Returns:

Whether there is a value

put

public void put(CellKey key,
       Object value)

iterator

public Iterator<Map.Entry<CellKey,Object>> iterator()

Specified by:

iterator in interface Iterable<Map.Entry<CellKey,Object>>

getBytes

public double getBytes()

Description copied from interface: SegmentDataset

Returns the number of bytes occupied by this dataset.

Specified by:

getBytes in interface SegmentDataset

Returns:

number of bytes

populateFrom

public void populateFrom(int[] pos,
                SegmentDataset data,
                CellKey key)

Specified by:

populateFrom in interface SegmentDataset

populateFrom

public void populateFrom(int[] pos,
                SegmentLoader.RowList rowList,
                int column)

Description copied from interface: SegmentDataset

Sets the value a given ordinal.

Specified by:

populateFrom in interface SegmentDataset

Parameters:

pos - Ordinal

rowList - Row list

column - Column of row list

getType

public SqlStatement.Type getType()

Description copied from interface: SegmentDataset

Returns the SQL type of the data contained in this dataset.

Specified by:

getType in interface SegmentDataset

Returns:

A value of SqlStatement.Type

createSegmentBody

public SegmentBody createSegmentBody(List<Pair<SortedSet<Comparable>,Boolean>> axes)

Description copied from interface: SegmentDataset

Return an immutable, final and serializable implementation of a SegmentBody in order to cache this dataset.

Specified by:

createSegmentBody in interface SegmentDataset

Parameters:

axes - An array with, for each axis, the set of axis values, sorted in natural order, and a flag saying whether the null value is also present. This is supplied by the SegmentLoader.

Returns:

A SegmentBody.