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

SparseSegmentDataset(Segment segment)

Method Summary

Object	get(CellKey pos) Returns the value at a given coordinate.
double	getBytes() Returns the number of bytes occupied by this dataset.
Iterator<Map.Entry<CellKey,Object>>	iterator()
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(Segment segment)

Method Detail

get

public Object get(CellKey pos)

Description copied from interface: SegmentDataset

Returns the value at a given coordinate.

Specified by:

get in interface SegmentDataset

Parameters:

pos - Coordinate position

Returns:

Value

put

public void put(CellKey key,
                Object value)

Specified by:

put in interface SegmentDataset

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