uk.ac.starlink.table

Class MetadataStarTable

java.lang.Object

uk.ac.starlink.table.AbstractStarTable

uk.ac.starlink.table.MetadataStarTable

All Implemented Interfaces:

Closeable, AutoCloseable, StarTable

public class MetadataStarTable
extends AbstractStarTable

Utility StarTable implementation which contains only metadata, no data. Suitable for passing to TableSink.acceptMetadata(uk.ac.starlink.table.StarTable).

Since:

14 Oct 2011

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
MetadataStarTable(ColumnInfo[] colInfos) Constructs a metadata table with given column metadata and an indeterminate number of rows.
MetadataStarTable(ColumnInfo[] colInfos, long rowCount) Constructs a metadata table with given column metadata and a given number of rows.

Method Summary

Modifier and Type	Method and Description
int	getColumnCount() Returns the number of columns in this table.
ColumnInfo	getColumnInfo(int icol) Returns the object describing the data in a given column.
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.
RowSplittable	getRowSplittable() Returns a default splittable which relies on table random access if available, or otherwise provides only sequential access (no splits).

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

checkedLongToInt, close, getCell, getColumnAuxDataInfos, getName, getParameters, getRow, getURL, isRandom, 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

MetadataStarTable

public MetadataStarTable(ColumnInfo[] colInfos)

Constructs a metadata table with given column metadata and an indeterminate number of rows.

Parameters:

colInfos - metadata items for each column

MetadataStarTable

public MetadataStarTable(ColumnInfo[] colInfos,
                         long rowCount)

Constructs a metadata table with given column metadata and a given number of rows.

Parameters:

colInfos - metadata items for each column

rowCount - row count, may be -1 to indicate unknown

Method Detail

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

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

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

getRowSplittable

public RowSplittable getRowSplittable()

Description copied from class: AbstractStarTable

Returns a default splittable which relies on table random access if available, or otherwise provides only sequential access (no splits).

It is often possible to provide a better implementation than this.

Specified by:

getRowSplittable in interface StarTable

Overrides:

getRowSplittable in class AbstractStarTable

Returns:

Tables.getDefaultRowSplittable(this)

See Also:

RowRunner

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