Package org.apache.wicket.pageStore

Class DiskPageStore

java.lang.Object

org.apache.wicket.pageStore.AbstractPersistentPageStore

org.apache.wicket.pageStore.DiskPageStore

All Implemented Interfaces:

IPageStore, IPersistentPageStore

public class DiskPageStore
extends AbstractPersistentPageStore
implements IPersistentPageStore

A storage of pages on disk.

All pages passed into this store are restricted to be SerializedPages.

Implementation note: DiskPageStore writes pages into a single file, appending new pages while overwriting the oldest pages. Since Ajax requests do not change the id of a page, DiskPageStore offers an optimization to overwrite the most recently written page, if it has the same id as a new page to write.

However this does not help in case of alternating requests between multiple browser windows: In this case requests are processed for different page ids and the oldest pages are constantly overwritten (this can easily happen with Ajax timers on one or more pages). This leads to pages with identical id superfluously kept in the file, while older pages are prematurely expelled. Any following request to these older pages will then fail with PageExpiredException.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	DiskPageStore.DiskData	Data held on disk.

Nested classes/interfaces inherited from class org.apache.wicket.pageStore.AbstractPersistentPageStore

AbstractPersistentPageStore.PersistedPage

Constructor Summary

Constructors

Constructor	Description
DiskPageStore(String applicationName, File fileStoreFolder, Bytes maxSizePerSession)	Create a store that supports SerializedPages only.

Method Summary

Modifier and Type	Method	Description
protected void	addPersistedPage(String sessionIdentifier, IManageablePage page)	Add a page.
void	destroy()	Destroy the store.
protected DiskPageStore.DiskData	getDiskData(String sessionIdentifier, boolean create)	Get the data on disk for the given session identifier.
protected IManageablePage	getPersistedPage(String sessionIdentifier, int id)
List<IPersistedPage>	getPersistedPages(String sessionIdentifier)	Get information about all persisted pages with the given session identifier.
Set<String>	getSessionIdentifiers()	Get the identifiers for all stored sessions.
Bytes	getTotalSize()	Get total size of all pages stored in all contexts.
protected void	removeAllPersistedPages(String sessionIdentifier)
protected void	removePersistedPage(String sessionIdentifier, IManageablePage page)
boolean	supportsVersioning()	Pages are already serialized.

Methods inherited from class org.apache.wicket.pageStore.AbstractPersistentPageStore

addPage, canBeAsynchronous, createSessionIdentifier, getPage, getSessionIdentifier, removeAllPages, removePage

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.wicket.pageStore.IPageStore

addPage, canBeAsynchronous, detach, end, getPage, removeAllPages, removePage, revertPage

Methods inherited from interface org.apache.wicket.pageStore.IPersistentPageStore

getSessionIdentifier

Constructor Detail

DiskPageStore

public DiskPageStore(String applicationName,
                     File fileStoreFolder,
                     Bytes maxSizePerSession)

Create a store that supports SerializedPages only.

Parameters:

applicationName - name of application

fileStoreFolder - folder to store to

maxSizePerSession - maximum size per session

See Also:

SerializingPageStore

Method Detail

supportsVersioning

public boolean supportsVersioning()

Pages are already serialized.

Specified by:

supportsVersioning in interface IPageStore

destroy

public void destroy()

Description copied from interface: IPageStore

Destroy the store.

Specified by:

destroy in interface IPageStore

Overrides:

destroy in class AbstractPersistentPageStore

getPersistedPage

protected IManageablePage getPersistedPage(String sessionIdentifier,
                                           int id)

Specified by:

getPersistedPage in class AbstractPersistentPageStore

removePersistedPage

protected void removePersistedPage(String sessionIdentifier,
                                   IManageablePage page)

Specified by:

removePersistedPage in class AbstractPersistentPageStore

removeAllPersistedPages

protected void removeAllPersistedPages(String sessionIdentifier)

Specified by:

removeAllPersistedPages in class AbstractPersistentPageStore

addPersistedPage

protected void addPersistedPage(String sessionIdentifier,
                                IManageablePage page)

Description copied from class: AbstractPersistentPageStore

Add a page.

Specified by:

addPersistedPage in class AbstractPersistentPageStore

Parameters:

sessionIdentifier - identifier of session

page - page to add

getDiskData

protected DiskPageStore.DiskData getDiskData(String sessionIdentifier,
                                             boolean create)

Get the data on disk for the given session identifier.

Parameters:

sessionIdentifier - identifier of session

Returns:

matching data

getSessionIdentifiers

public Set<String> getSessionIdentifiers()

Description copied from interface: IPersistentPageStore

Get the identifiers for all stored sessions.

Specified by:

getSessionIdentifiers in interface IPersistentPageStore

Returns:

the identifiers of all session.

getPersistedPages

public List<IPersistedPage> getPersistedPages(String sessionIdentifier)

Description copied from interface: IPersistentPageStore

Get information about all persisted pages with the given session identifier.

Specified by:

getPersistedPages in interface IPersistentPageStore

Parameters:

sessionIdentifier - key

Returns:

a list of the last N page windows

getTotalSize

public Bytes getTotalSize()

Description copied from interface: IPersistentPageStore

Get total size of all pages stored in all contexts.

Optional operation, may return null.

Specified by:

getTotalSize in interface IPersistentPageStore

Returns:

total size or null