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>, PageFileStatistics

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.

Field Summary

private Map<Integer,P>

file Holds the pages.

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

emptyPages, nextPageID, pageSize

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

readAccess, writeAccess

Constructor Summary

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

Method Summary

void	clear() Clears this PageFile.
void	deletePage(int pageID) Deletes the node with the specified id from this file.
P	readPage(int pageID) Reads the page with the given id from this file.
protected void	writePage(Integer pageID, P page) Perform the actual page write operation.

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

getInnerStatistics, getNextPageID, getPageSize, initialize, setNextPageID, setPageID

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

close, getReadOperations, getWriteOperations, resetPageAccess, writePage

Methods inherited from class java.lang.Object

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

Field Detail

file

private final Map<Integer,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(Integer 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.