uk.ac.starlink.table

Class ColumnRandomWrapperStarTable

java.lang.Object

uk.ac.starlink.table.WrapperStarTable

uk.ac.starlink.table.RandomWrapperStarTable

uk.ac.starlink.table.ColumnRandomWrapperStarTable

All Implemented Interfaces:

StarTable

public class ColumnRandomWrapperStarTable
extends RandomWrapperStarTable

RandomWrapperStarTable which works by storing the data in a set of fixed length arrays. This will be more efficient on memory used than storing it in rows if some of the columns have a primitive type, but it may make reading slower.

See Also:

RowRandomWrapperStarTable

Field Summary

Fields inherited from class uk.ac.starlink.table.WrapperStarTable

baseTable

Constructor Summary

Constructors

Constructor and Description
ColumnRandomWrapperStarTable(StarTable baseTable, int nrow) Constructs a new table to store a given number of rows.

Method Summary

Modifier and Type	Method and Description
long	getRowCount() Returns the number of rows in this table, if known.
protected java.lang.Object[]	retrieveStoredRow(long lrow) Retrieves the row stored by the lrow'th invocation of RandomWrapperStarTable.storeNextRow(java.lang.Object[]).
protected void	storeNextRow(java.lang.Object[] row) Stores the next row encountered in the base table's row sequence.

Methods inherited from class uk.ac.starlink.table.RandomWrapperStarTable

getCell, getColumnCount, getColumnInfo, getRow, getRowSequence, getURL, isRandom

Methods inherited from class uk.ac.starlink.table.WrapperStarTable

checkedLongToInt, getBaseTable, getColumnAuxDataInfos, getName, getParameterByName, getParameters, setName, setParameter, setURL, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ColumnRandomWrapperStarTable

public ColumnRandomWrapperStarTable(StarTable baseTable,
                                    int nrow)
                             throws java.io.IOException

Constructs a new table to store a given number of rows. The nrow argument supplied is the number that this table will have, which may or may not match that of the base table.

Parameters:

baseTable - base table

nrow - number of rows in this table

Throws:

java.io.IOException

Method Detail

getRowCount

public long getRowCount()

Description copied from interface: StarTable

Returns the number of rows in this table, if known. If the number of rows cannot be (easily) determined, a value of -1 will be returned.

Specified by:

getRowCount in interface StarTable

Overrides:

getRowCount in class RandomWrapperStarTable

Returns:

the number of rows, or -1

storeNextRow

protected void storeNextRow(java.lang.Object[] row)

Description copied from class: RandomWrapperStarTable

Stores the next row encountered in the base table's row sequence. This will be called up to getRowCount times with the contents of each row of the base table in sequence. Implementations should store it in some way that it can be retrieved by RandomWrapperStarTable.retrieveStoredRow(long).

Specified by:

storeNextRow in class RandomWrapperStarTable

Parameters:

row - the row to store

retrieveStoredRow

protected java.lang.Object[] retrieveStoredRow(long lrow)

Description copied from class: RandomWrapperStarTable

Retrieves the row stored by the lrow'th invocation of RandomWrapperStarTable.storeNextRow(java.lang.Object[]). This method will not be called with a value of lrow greater than or equal to the number of times storeNextRow has been called already.

Specified by:

retrieveStoredRow in class RandomWrapperStarTable

Parameters:

lrow - the index of the row to retrieve

Returns:

the lrow'th row to be stored by RandomWrapperStarTable.storeNextRow(java.lang.Object[])