uk.ac.starlink.table

Class RandomStarTable

java.lang.Object

uk.ac.starlink.table.AbstractStarTable

uk.ac.starlink.table.RandomStarTable

All Implemented Interfaces:

Closeable, AutoCloseable, StarTable

Direct Known Subclasses:

BeanStarTable, ColumnStarTable, ConstantStarTable, FitsStarTable, RandomResultSetStarTable, RowListStarTable, ValueInfoMapGroupTable

public abstract class RandomStarTable
extends AbstractStarTable

Implements a StarTable based on row and cell accessor methods that are random access and thread-safe.

The isRandom method always returns true, and the getRowSequence method is implemented using the table's (abstract) getCell and getRow methods, which must be safe for concurrent use from multiple threads. This implementation is only suitable where table data access is naturally thread-safe; in cases where synchronization or some other potentially expensive mechanism is used to secure thread-safety of getCell, it is better to use a different implementation with a better getRowSequence implementation.

Author:

Mark Taylor (Starlink)

Constructor Summary

Constructors

Constructor and Description
RandomStarTable()

Method Summary

Modifier and Type	Method and Description
abstract Object	getCell(long irow, int icol) Implementations of this method must be safe for concurrent calls from multiple threads.
RowAccess	getRowAccess() Returns a RowAccess object based on the random data access methods of this table.
abstract long	getRowCount() Implementations must supply a non-negative return value.
RowSequence	getRowSequence() Returns a RowSequence object based on the random data access methods of this table.
boolean	isRandom() Returns true.

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

checkedLongToInt, close, getColumnAuxDataInfos, getColumnCount, getColumnInfo, getName, getParameters, getRow, getRowSplittable, getURL, setName, setParameters, setURL

Methods inherited from class java.lang.Object

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

Methods inherited from interface uk.ac.starlink.table.StarTable

getParameterByName, setParameter

Constructor Detail

RandomStarTable

public RandomStarTable()

Method Detail

isRandom

public boolean isRandom()

Returns true.

Specified by:

isRandom in interface StarTable

Overrides:

isRandom in class AbstractStarTable

Returns:

true

getRowSequence

public RowSequence getRowSequence()

Returns a RowSequence object based on the random data access methods of this table.

Specified by:

getRowSequence in interface StarTable

Specified by:

getRowSequence in class AbstractStarTable

Returns:

a row iterator

getRowAccess

public RowAccess getRowAccess()

Returns a RowAccess object based on the random data access methods of this table.

Specified by:

getRowAccess in interface StarTable

Overrides:

getRowAccess in class AbstractStarTable

Returns:

a row access

getRowCount

public abstract long getRowCount()

Implementations must supply a non-negative return value.

Specified by:

getRowCount in interface StarTable

Specified by:

getRowCount in class AbstractStarTable

Returns:

the number of rows in the table

getCell

public abstract Object getCell(long irow,
                               int icol)
                        throws IOException

Implementations of this method must be safe for concurrent calls from multiple threads.

Specified by:

getCell in interface StarTable

Overrides:

getCell in class AbstractStarTable

Parameters:

irow - the index of the cell's row

icol - the index of the cell's column

Returns:

the contents of this cell

Throws:

IOException - if there is an error reading the data