de.lmu.ifi.dbs.elki.persistent

Class AbstractStoringPageFile<P extends Page>

java.lang.Object

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

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

Type Parameters:

P - Page type

All Implemented Interfaces:

PageFile<P>

Direct Known Subclasses:

MemoryPageFile, OnDiskArrayPageFile, PersistentPageFile

public abstract class AbstractStoringPageFile<P extends Page>
extends AbstractPageFile<P>

Abstract class implementing general methods of a PageFile. A PageFile stores objects that implement the Page interface.

Author:

Elke Achtert

Field Summary

Fields

Modifier and Type	Field and Description
protected Stack<Integer>	emptyPages A stack holding the empty page ids.
protected int	nextPageID The last page ID.
protected int	pageSize The size of a page in Bytes.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractStoringPageFile(int pageSize) Creates a new PageFile.

Method Summary

Methods

Modifier and Type	Method and Description
void	deletePage(int pageID) Deletes the node with the specified id from this file.
private int	getNextEmptyPageID() Returns the next empty page id.
int	getNextPageID() Returns the next page id.
int	getPageSize() Get the page size of this page file.
boolean	initialize(PageHeader header) Initialize the page file with the given header - return "true" if the file already existed.
void	logStatistics() Log some statistics to the appropriate logger.
void	setNextPageID(int nextPageID) Sets the next page id.
int	setPageID(P page) Sets the id of the given page.

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

close, countRead, countWrite, getLogger, writePage, writePage

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.lmu.ifi.dbs.elki.persistent.PageFile

clear, readPage

Field Detail

emptyPages

protected Stack<Integer> emptyPages

A stack holding the empty page ids.

nextPageID

protected int nextPageID

The last page ID.

pageSize

protected int pageSize

The size of a page in Bytes.

Constructor Detail

AbstractStoringPageFile

protected AbstractStoringPageFile(int pageSize)

Creates a new PageFile.

Method Detail

setPageID

public int setPageID(P page)

Sets the id of the given page.

Parameters:

page - the page to set the id

Returns:

the page id

deletePage

public void deletePage(int pageID)

Deletes the node with the specified id from this file.

Parameters:

pageID - the id of the node to be deleted

getNextEmptyPageID

private int getNextEmptyPageID()

Returns the next empty page id.

Returns:

the next empty page id

getNextPageID

public int getNextPageID()

Returns the next page id.

Returns:

the next page id

setNextPageID

public void setNextPageID(int nextPageID)

Sets the next page id.

Parameters:

nextPageID - the next page id to be set

getPageSize

public int getPageSize()

Get the page size of this page file.

Returns:

page size

initialize

public boolean initialize(PageHeader header)

Initialize the page file with the given header - return "true" if the file already existed.

Parameters:

header - Header

Returns:

true when the file already existed.

logStatistics

public void logStatistics()

Description copied from interface: PageFile

Log some statistics to the appropriate logger.

Specified by:

logStatistics in interface PageFile<P extends Page>

Overrides:

logStatistics in class AbstractPageFile<P extends Page>