de.lmu.ifi.dbs.elki.persistent

Class MemoryPageFile<P extends Page>

java.lang.Object

de.lmu.ifi.dbs.elki.persistent.AbstractPageFile<P>

de.lmu.ifi.dbs.elki.persistent.AbstractStoringPageFile<P>

de.lmu.ifi.dbs.elki.persistent.MemoryPageFile<P>

Type Parameters:

P - Page type

All Implemented Interfaces:

PageFile<P>

public class MemoryPageFile<P extends Page>
extends AbstractStoringPageFile<P>

A memory based implementation of a PageFile that simulates I/O-access.
Implemented as a Map with keys representing the ids of the saved pages.

Author:

Elke Achtert

Field Summary

Fields

Modifier and Type	Field and Description
private TIntObjectMap<P>	file Holds the pages.
private static Logging	LOG Class logger.

Fields inherited from class de.lmu.ifi.dbs.elki.persistent.AbstractStoringPageFile

emptyPages, nextPageID, pageSize

Constructor Summary

Constructors

Constructor and Description
MemoryPageFile(int pageSize) Creates a new MemoryPageFile that is supported by a cache with the specified parameters.

Method Summary

Methods

Modifier and Type	Method and Description
void	clear() Clears this PageFile.
void	deletePage(int pageID) Deletes the node with the specified id from this file.
protected Logging	getLogger() Get the class logger.
P	readPage(int pageID) Reads the page with the given id from this file.
protected void	writePage(int pageID, P page) Perform the actual page write operation.

Methods inherited from class de.lmu.ifi.dbs.elki.persistent.AbstractStoringPageFile

getNextPageID, getPageSize, initialize, logStatistics, setNextPageID, setPageID

Methods inherited from class de.lmu.ifi.dbs.elki.persistent.AbstractPageFile

close, countRead, countWrite, writePage

Methods inherited from class java.lang.Object

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

Field Detail

LOG

private static final Logging LOG

Class logger.

file

private final TIntObjectMap<P extends Page> file

Holds the pages.

Constructor Detail

MemoryPageFile

public MemoryPageFile(int pageSize)

Creates a new MemoryPageFile that is supported by a cache with the specified parameters.

Parameters:

pageSize - the size of a page in Bytes

Method Detail

readPage

public P readPage(int pageID)

Description copied from interface: PageFile

Reads the page with the given id from this file.

Parameters:

pageID - the id of the page to be returned

Returns:

the page with the given pageId

writePage

protected void writePage(int pageID,
             P page)

Description copied from class: AbstractPageFile

Perform the actual page write operation.

Specified by:

writePage in class AbstractPageFile<P extends Page>

Parameters:

pageID - Page id

page - Page to write

deletePage

public void deletePage(int pageID)

Description copied from class: AbstractStoringPageFile

Deletes the node with the specified id from this file.

Specified by:

deletePage in interface PageFile<P extends Page>

Overrides:

deletePage in class AbstractStoringPageFile<P extends Page>

Parameters:

pageID - the id of the node to be deleted

clear

public void clear()

Description copied from interface: PageFile

Clears this PageFile.

getLogger

protected Logging getLogger()

Description copied from class: AbstractPageFile

Get the class logger.

Specified by:

getLogger in class AbstractPageFile<P extends Page>

Returns:

Logger