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

Version:

$Id: //open/mondrian/src/main/mondrian/rolap/agg/SparseSegmentDataset.java#13 $

Author:

jhyde

Field Summary

(package private) Map<CellKey,Object>

values

Constructor Summary

SparseSegmentDataset(Segment segment)

Method Summary

SegmentBody	createSegmentBody(SortedSet<Comparable<?>>[] axisValueSets, boolean[] nullAxisFlags) Must 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

Field Detail

values

final Map<CellKey,Object> values

Constructor Detail

SparseSegmentDataset

SparseSegmentDataset(Segment segment)

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(SortedSet<Comparable<?>>[] axisValueSets,
                                     boolean[] nullAxisFlags)

Description copied from interface: SegmentDataset

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

Specified by:

createSegmentBody in interface SegmentDataset

Parameters:

axisValueSets - An array of SortedSets of Comparables. This is supplied by the SegmentLoader.

nullAxisFlags - An array of booleans indicating which segment axis has null values. This is supplied by the SegmentLoader.

Returns:

A SegmentBody object.

See Also:

SegmentBody.createSegmentDataset(Segment)