uk.ac.starlink.table.storage

Class ListRowStore

java.lang.Object

uk.ac.starlink.table.storage.ListRowStore

All Implemented Interfaces:

RowStore, TableSink

public class ListRowStore
extends java.lang.Object
implements RowStore

Implementation of RowStore which stores data in memory. The current implementation uses a RowListStarTable. This is better-behaved than the RowStore contract requires; it is guaranteed to be able to store any StarTable object (acceptMetadata(uk.ac.starlink.table.StarTable) will not throw a TableFormatException). Cautious users of this class will note the fact that for large tables, acceptRow(java.lang.Object[]) may throw an OutOfMemoryError.

Since:

3 Aug 2004

Constructor Summary

Constructors

Constructor and Description
ListRowStore()

Method Summary

Modifier and Type	Method and Description
void	acceptMetadata(StarTable meta) Takes delivery of a row-less StarTable object which defines the metadata of the table to be transmitted.
void	acceptRow(java.lang.Object[] row) Accepts a row.
void	endRows() Signals that there are no more rows to be transmitted.
StarTable	getStarTable() Obtains a StarTable which contains the data and metadata that have been written into this sink.

Methods inherited from class java.lang.Object

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

Constructor Detail

ListRowStore

public ListRowStore()

Method Detail

acceptMetadata

public void acceptMetadata(StarTable meta)

Description copied from interface: TableSink

Takes delivery of a row-less StarTable object which defines the metadata of the table to be transmitted. If the number of rows that will be transmitted via subsequent calls to acceptRow is known, this value should be made available as the row count of meta (StarTable.getRowCount()); if it is not known, the row count should be -1. However, this object should not attempt to read any of meta's cell data.

The data to be transmitted in subsequent calls of acceptRow must match the metadata transmitted in this call in the same way that rows of a StarTable must match its own metadata (number and content clases of columns etc). If this sink cannot dispose of a table corresponding to meta then it may throw a TableFormatException - this may be the case if for instance meta has columns with types that this sink can't deal with.

Specified by:

acceptMetadata in interface TableSink

Parameters:

meta - table metadata object

acceptRow

public void acceptRow(java.lang.Object[] row)
               throws java.io.IOException

Accepts a row.

Specified by:

acceptRow in interface TableSink

Parameters:

row - table data row

Throws:

java.lang.OutOfMemoryError - if it's run out of memory

java.io.IOException

endRows

public void endRows()

Description copied from interface: TableSink

Signals that there are no more rows to be transmitted.

Specified by:

endRows in interface TableSink

getStarTable

public StarTable getStarTable()

Description copied from interface: RowStore

Obtains a StarTable which contains the data and metadata that have been written into this sink. In general it is only legal to call this method following a call to TableSink.endRows(); failing to observe this sequence may earn you an IllegalStateException

Specified by:

getStarTable in interface RowStore

Returns:

a random-access StarTable containing the written rows