uk.ac.starlink.feather

Class FeatherStarTable

java.lang.Object

uk.ac.starlink.table.AbstractStarTable

uk.ac.starlink.feather.FeatherStarTable

All Implemented Interfaces:

Closeable, AutoCloseable, StarTable

public class FeatherStarTable
extends AbstractStarTable

Adaptor from FeatherTable to StarTable.

Since:

26 Feb 2020

Author:

Mark Taylor

Field Summary

Fields

Modifier and Type	Field and Description
static String	DESCRIPTION_KEY JSON key used to store description text in column user metadata.
static ValueInfo	FTYPE_INFO Aux metadata key for column feather type value.
static String	META_KEY JSON key to store miscellaneous/broken metadata in column metadata.
static String	SHAPE_KEY JSON key to store stringified array shape in column user metadata.
static String	UCD_KEY JSON key used to store UCDs in column user metadata.
static String	UNIT_KEY JSON key used to store units in column user metadata.
static String	UTYPE_KEY JSON key used to store Utypes in column user metadata.

Constructor Summary

Constructors

Constructor and Description
FeatherStarTable(uk.ac.bristol.star.feather.FeatherTable ftable) Constructs a FeatherStarTable from a FeatherTable.
FeatherStarTable(File file) Constructs a FeatherStarTable from a File.

Method Summary

Modifier and Type	Method and Description
void	close() Does nothing, but perhaps it ought to try to clear up resources related to the mapped buffers.
Object	getCell(long irow, int icol) The AbstractStarTable implementation of this method throws an UnsupportedOperationException, since unless otherwise provided there is no random access.
int	getColumnCount() Returns the number of columns in this table.
ColumnInfo	getColumnInfo(int icol) Returns the object describing the data in a given column.
String	getName() Returns the name of this table, if it has one.
Object	getRow(long irow, int icol)
RowAccess	getRowAccess() Returns an object which can provide random access to this table's data, if random access is implemented.
long	getRowCount() Returns the number of rows in this table, if known.
RowSequence	getRowSequence() Returns an object which can iterate over all the rows in the table sequentially.
boolean	isRandom() The AbstractStarTable implementation of this method returns false.

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

checkedLongToInt, getColumnAuxDataInfos, 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

Field Detail

UCD_KEY

public static final String UCD_KEY

JSON key used to store UCDs in column user metadata.

See Also:

Constant Field Values

UTYPE_KEY

public static final String UTYPE_KEY

JSON key used to store Utypes in column user metadata.

See Also:

Constant Field Values

UNIT_KEY

public static final String UNIT_KEY

JSON key used to store units in column user metadata.

See Also:

Constant Field Values

DESCRIPTION_KEY

public static final String DESCRIPTION_KEY

JSON key used to store description text in column user metadata.

See Also:

Constant Field Values

SHAPE_KEY

public static final String SHAPE_KEY

JSON key to store stringified array shape in column user metadata.

See Also:

Constant Field Values

META_KEY

public static final String META_KEY

JSON key to store miscellaneous/broken metadata in column metadata.

See Also:

Constant Field Values

FTYPE_INFO

public static final ValueInfo FTYPE_INFO

Aux metadata key for column feather type value.

Constructor Detail

FeatherStarTable

public FeatherStarTable(uk.ac.bristol.star.feather.FeatherTable ftable)

Constructs a FeatherStarTable from a FeatherTable.

Parameters:

ftable - feather table object

FeatherStarTable

public FeatherStarTable(File file)
                 throws IOException

Constructs a FeatherStarTable from a File.

Parameters:

file - file

Throws:

IOException

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

Specified by:

getColumnCount in class AbstractStarTable

Returns:

the number of columns

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

Specified by:

getRowCount in class AbstractStarTable

Returns:

the number of rows, or -1

isRandom

public boolean isRandom()

Description copied from class: AbstractStarTable

The AbstractStarTable implementation of this method returns false.

Specified by:

isRandom in interface StarTable

Overrides:

isRandom in class AbstractStarTable

Returns:

true if table random access methods are available

getName

public String getName()

Description copied from interface: StarTable

Returns the name of this table, if it has one. The meaning of the name is not defined, but it will typically be a short string of text indicating the identity of this table.

Specified by:

getName in interface StarTable

Overrides:

getName in class AbstractStarTable

Returns:

a name for this table, or null if no suitable one exists

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

Specified by:

getColumnInfo in class AbstractStarTable

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 class: AbstractStarTable

The AbstractStarTable implementation of this method throws an UnsupportedOperationException, since unless otherwise provided there is no random access.

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

getRow

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

Throws:

IOException

getRowSequence

public RowSequence getRowSequence()

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

Specified by:

getRowSequence in class AbstractStarTable

Returns:

new RowSequence

getRowAccess

public RowAccess getRowAccess()

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 AbstractStarTable

Returns:

new RowAccess

close

public void close()
           throws IOException

Does nothing, but perhaps it ought to try to clear up resources related to the mapped buffers.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface StarTable

Overrides:

close in class AbstractStarTable

Throws:

IOException