uk.ac.starlink.table

Class ExplodedStarTable

java.lang.Object

uk.ac.starlink.table.WrapperStarTable

uk.ac.starlink.table.ExplodedStarTable

All Implemented Interfaces:

Closeable, AutoCloseable, StarTable

public class ExplodedStarTable
extends WrapperStarTable

Wrapper table which takes any column whose value is N-element arrays and turns it into N scalar-valued columns.

Since:

2 Mar 2005

Author:

Mark Taylor (Starlink)

Field Summary

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

baseTable

Constructor Summary

Constructors

Constructor and Description
ExplodedStarTable(StarTable baseTable) Constructs a table in which all fixed-length array-valued columns are exploded.
ExplodedStarTable(StarTable baseTable, boolean[] colFlags) Constructs a table in which specified columns are exploded.

Method Summary

Modifier and Type	Method and Description
Object	getCell(long irow, int icol) Returns the contents of a given table cell.
int	getColumnCount() Returns the number of columns in this table.
ColumnInfo	getColumnInfo(int icol) Returns the object describing the data in a given column.
Object[]	getRow(long irow) Returns the contents of a given table row.
RowAccess	getRowAccess() Returns an object which can provide random access to this table's data, if random access is implemented.
RowSequence	getRowSequence() Returns an object which can iterate over all the rows in the table sequentially.
RowSplittable	getRowSplittable() Returns an object which can iterate over all the rows in the table, but which may also be requested to split recursively for potentially parallel processing.

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

checkedLongToInt, close, getBaseTable, getColumnAuxDataInfos, getName, getParameterByName, getParameters, getRowCount, getURL, isRandom, setName, setParameter, setURL, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ExplodedStarTable

public ExplodedStarTable(StarTable baseTable,
                         boolean[] colFlags)

Constructs a table in which specified columns are exploded. All of the specified columns must have values which are fixed-length arrays.

Parameters:

baseTable - base table

colFlags - array of flags the same length as the number of columns in baseTable; true elements indicate columns in the base table which should be exploded

Throws:

IllegalArgumentException - if any column specified by colFlags has a type which is not a fixed-length array

ExplodedStarTable

public ExplodedStarTable(StarTable baseTable)

Constructs a table in which all fixed-length array-valued columns are exploded.

Parameters:

baseTable - base table

Method Detail

getColumnCount

public int getColumnCount()

Description copied from interface: StarTable

Returns the number of columns in this table.

Specified by:

getColumnCount in interface StarTable

Overrides:

getColumnCount in class WrapperStarTable

Returns:

the number of columns

getColumnInfo

public ColumnInfo getColumnInfo(int icol)

Description copied from interface: StarTable

Returns the object describing the data in a given column.

Specified by:

getColumnInfo in interface StarTable

Overrides:

getColumnInfo in class WrapperStarTable

Parameters:

icol - the column for which header information is required

Returns:

a ValueInfo object for column icol

getCell

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

Description copied from interface: StarTable

Returns the contents of a given table cell. The class of the returned object should be the same as, or a subclass of, the class returned by getColumnInfo(icol).getContentClass().

This method is safe for concurrent use from multiple threads, but in general it is recommended to use a RowAccess instead.

Specified by:

getCell in interface StarTable

Overrides:

getCell in class WrapperStarTable

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

getRow

public Object[] getRow(long irow)
                throws IOException

Description copied from interface: StarTable

Returns the contents of a given table row. The returned value is equivalent to an array formed of all the objects returned by getCell(irow,icol) for all the columns icol in sequence.

This method is safe for concurrent use from multiple threads, but in general it is recommended to use a RowAccess instead.

Specified by:

getRow in interface StarTable

Overrides:

getRow in class WrapperStarTable

Parameters:

irow - the index of the row to retrieve

Returns:

an array of the objects in each cell in row irow

Throws:

IOException - if there is an error reading the data

getRowSequence

public RowSequence getRowSequence()
                           throws IOException

Description copied from interface: StarTable

Returns an object which can iterate over all the rows in the table sequentially. Each such returned object is safe for use within a single thread, but not in general from multiple threads concurrently.

Specified by:

getRowSequence in interface StarTable

Overrides:

getRowSequence in class WrapperStarTable

Returns:

new RowSequence

Throws:

IOException - if there is an error providing access

getRowAccess

public RowAccess getRowAccess()
                       throws IOException

Description copied from interface: StarTable

Returns an object which can provide random access to this table's data, if random access is implemented. Each such returned object is safe for use within a single thread, but not in general from multiple threads concurrently.

Specified by:

getRowAccess in interface StarTable

Overrides:

getRowAccess in class WrapperStarTable

Returns:

new RowAccess

Throws:

IOException - if there is an error setting up access

getRowSplittable

public RowSplittable getRowSplittable()
                               throws IOException

Description copied from interface: StarTable

Returns an object which can iterate over all the rows in the table, but which may also be requested to split recursively for potentially parallel processing.

The return value must be non-null, and may provide splitting arrangements specially appropriate for the implementation. If this table 'wraps' an upstream table, it is usually best to base the implementation on calls to the the upstream getRowSplittable method, so that upstream policy about how to divide up the table is respected. However, implementations without special requirements may return Tables.getDefaultRowSplittable(this).

Specified by:

getRowSplittable in interface StarTable

Overrides:

getRowSplittable in class WrapperStarTable

Returns:

new RowSplittable

Throws:

IOException

See Also:

RowRunner