uk.ac.starlink.ttools.filter

Class CacheFilter

java.lang.Object

uk.ac.starlink.ttools.filter.BasicFilter

uk.ac.starlink.ttools.filter.CacheFilter

All Implemented Interfaces:

ProcessingFilter, ProcessingStep

public class CacheFilter
extends BasicFilter
implements ProcessingStep

Processing step which caches the current table in a disk or memory cache (according to the default StoragePolicy). This is useful for efficiency reasons if downstream steps are going to make random-access or multiple use of an expensive step.

Since:

8 Mar 2005

Author:

Mark Taylor (Starlink)

Constructor Summary

Constructors

Constructor and Description
CacheFilter()

Method Summary

Modifier and Type	Method and Description
ProcessingStep	createStep(Iterator<String> argIt) Creates a new ProcessingStep based on a sequence of command-line arguments.
protected String[]	getDescriptionLines()
StarTable	wrap(StarTable baseTable) Performs a table filtering step.

Methods inherited from class uk.ac.starlink.ttools.filter.BasicFilter

explainSyntax, getDescription, getName, getUsage

Methods inherited from class java.lang.Object

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

Constructor Detail

CacheFilter

public CacheFilter()

Method Detail

getDescriptionLines

protected String[] getDescriptionLines()

Specified by:

getDescriptionLines in class BasicFilter

createStep

public ProcessingStep createStep(Iterator<String> argIt)

Description copied from interface: ProcessingFilter

Creates a new ProcessingStep based on a sequence of command-line arguments. The argIt argument is an iterator over the command-line arguments positioned just before any arguments intended for this filter. If legal, any that can be comprehended by this filter should be read (iterated over) and removed, and a ProcessingStep should accordingly be returned. In the case of a successful return, it is essential that no arguments other than the ones intended for this filter are read from the iterator.

If the argument list is badly-formed as far as this filter is concerned, an ArgException should be thrown.

Specified by:

createStep in interface ProcessingFilter

Parameters:

argIt - iterator over command-line arguments positioned at the first one

wrap

public StarTable wrap(StarTable baseTable)
               throws IOException

Description copied from interface: ProcessingStep

Performs a table filtering step.

Specified by:

wrap in interface ProcessingStep

Parameters:

baseTable - input table

Returns:

output table

Throws:

IOException