org.apache.wicket.protocol.http.pagestore
Class DiskPageStore

java.lang.Object
  org.apache.wicket.protocol.http.pagestore.AbstractPageStore
      org.apache.wicket.protocol.http.pagestore.DiskPageStore

All Implemented Interfaces:

SecondLevelCacheSessionStore.IPageStore, SecondLevelCacheSessionStore.ISerializationAwarePageStore

public class DiskPageStore
extends AbstractPageStore
implements SecondLevelCacheSessionStore.ISerializationAwarePageStore

SecondLevelCacheSessionStore.IPageStore implementation that stores the serialized pages grouped in a single file per pagemap.

This store was designed to overcome the problems of FilePageStore which stores the pages in separate files per page.

DiskPageStore allows to set maximum size for pagemap file and maximum size for session. If the maximum size for session is exceeded, the last recently used pagemap file is removed.

Author:

Matej Knopp

Nested Class Summary

protected static class	DiskPageStore.PageMapEntry Each PageMap is represented by this class.
protected static class	DiskPageStore.SessionEntry Represents a session,

Nested classes/interfaces inherited from class org.apache.wicket.protocol.http.pagestore.AbstractPageStore

AbstractPageStore.SerializedPage

Constructor Summary

DiskPageStore()
Creates a new DiskPageStore instance.

DiskPageStore(java.io.File fileStoreFolder, int maxSizePerPagemap, int maxSizePerSession, int fileChannelPoolCapacity)
Creates a new DiskPageStore instance.

DiskPageStore(int maxSizePerPagemap, int maxSizePerSession, int fileChannelPoolCapacity)
Creates a new DiskPageStore instance.

Method Summary

boolean	containsPage(java.lang.String sessionId, java.lang.String pageMapName, int pageId, int pageVersion) Returns whether the PageStore contains given page.
Page	convertToPage(java.lang.Object page)
void	destroy() Destroy the store.
protected void	flushPagesToSaveList(java.lang.String sessionId, java.util.List list) Saves all entries from the specified list.
protected java.io.File	getFileStoreFolder() Returns the "root" file store folder.
protected int	getLastRecentlySerializedPagesCacheSize()
protected int	getMaxSizePerPageMap() Return maximum pagemap file size (in bytes).
protected int	getMaxSizePerSession() Returns maximum size per session (in bytes).
Page	getPage(java.lang.String sessionId, java.lang.String pagemap, int id, int versionNumber, int ajaxVersionNumber) Restores a page version from the persistent layer.
protected java.util.List	getPagesToSaveList(java.lang.String sessionId) Returns the list of pages to be saved for the specified session id.
protected int	getSavingThreadSleepTime() Returns the amount time in milliseconds for the saving thread to sleep between checking whether there are pending serialized pages to be saved.
protected DiskPageStore.SessionEntry	getSessionEntry(java.lang.String sessionId, boolean createIfDoesNotExist) Returns the SessionEntry for session with given id.
protected java.io.File	getSessionFolder(java.lang.String sessionId, boolean create) Returns the folder for the specified sessions.
protected boolean	isSynchronous() Returns whether the DiskPageStore should work in synchronous or asynchronous mode.
protected void	onPagesSerialized(java.lang.String sessionId, java.util.List pages) Hook for processing serialized pages (e.g.
void	pageAccessed(java.lang.String sessionId, Page page) This method is called when the page is accessed.
java.io.Serializable	prepareForSerialization(java.lang.String sessionId, java.lang.Object page) Process the page before the it gets serialized.
void	removePage(java.lang.String sessionId, java.lang.String pageMap, int id) Removes a page from the persistent layer.
java.lang.Object	restoreAfterSerialization(java.io.Serializable serializable) This method should restore the serialized page to intermediate object that can be converted to real page instance using SecondLevelCacheSessionStore.ISerializationAwarePageStore.convertToPage(Object).
void	setLastRecentlySerializedPagesCacheSize(int lastRecentlySerializedPagesCacheSize) Sets the number of last recently serialized pages kept in cache.
protected boolean	storeAfterSessionReplication()
void	storePage(java.lang.String sessionId, Page page) Stores the page to a persistent layer.
protected void	storeSerializedPages(java.lang.String sessionId, java.util.List pages) Stores the serialized pages.
void	unbind(java.lang.String sessionId) The pagestore should cleanup all the pages for that sessionid.

Methods inherited from class org.apache.wicket.protocol.http.pagestore.AbstractPageStore

deserializePage, serializePage

Methods inherited from class java.lang.Object

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

Constructor Detail

DiskPageStore

public DiskPageStore(java.io.File fileStoreFolder,
                     int maxSizePerPagemap,
                     int maxSizePerSession,
                     int fileChannelPoolCapacity)

Creates a new DiskPageStore instance.

Parameters:

fileStoreFolder - folder in which the session folders containing pagemap files will be stored

maxSizePerPagemap - the maximum size of pagemap file (in bytes)

maxSizePerSession - the maximum size of session (in bytes)

fileChannelPoolCapacity - the maximum number of concurrently opened files (higher number improves performance under heavy load).

DiskPageStore

public DiskPageStore(int maxSizePerPagemap,
                     int maxSizePerSession,
                     int fileChannelPoolCapacity)

Creates a new DiskPageStore instance.

Parameters:

maxSizePerPagemap - the maximum size of pagemap file (in bytes)

maxSizePerSession - the maximum size of session (in bytes)

fileChannelPoolCapacity - the maximum number of concurrently opened files (higher number improves performance under heavy load).

DiskPageStore

public DiskPageStore()

Creates a new DiskPageStore instance.

Method Detail

getSessionFolder

protected java.io.File getSessionFolder(java.lang.String sessionId,
                                        boolean create)

Returns the folder for the specified sessions. If the folder doesn't exist and the create flag is set, the folder will be created.

Parameters:

sessionId -

create -

Returns:

folder used to store session data

getMaxSizePerPageMap

protected int getMaxSizePerPageMap()

Return maximum pagemap file size (in bytes).

Returns:

getMaxSizePerSession

protected int getMaxSizePerSession()

Returns maximum size per session (in bytes). After the session exceeds this size, appropriate number of last recently used pagemap files will be removed.

Returns:

getFileStoreFolder

protected java.io.File getFileStoreFolder()

Returns the "root" file store folder.

Returns:

destroy

public void destroy()

Description copied from interface: SecondLevelCacheSessionStore.IPageStore

Destroy the store.

Specified by:

destroy in interface SecondLevelCacheSessionStore.IPageStore

See Also:

SecondLevelCacheSessionStore.IPageStore.destroy()

getSessionEntry

protected DiskPageStore.SessionEntry getSessionEntry(java.lang.String sessionId,
                                                     boolean createIfDoesNotExist)

Returns the SessionEntry for session with given id. If the entry does not yet exist and the createIfDoesNotExist attribute is set, new SessionEntry will be created.

Parameters:

sessionId -

createIfDoesNotExist -

Returns:

getPage

public Page getPage(java.lang.String sessionId,
                    java.lang.String pagemap,
                    int id,
                    int versionNumber,
                    int ajaxVersionNumber)

Description copied from interface: SecondLevelCacheSessionStore.IPageStore

Restores a page version from the persistent layer.

Note that the versionNumber and ajaxVersionNumber parameters may be -1.

• If ajaxVersionNumber is -1 and versionNumber is specified, the page store must return the page with highest ajax version.
• If both versionNumber and ajaxVersioNumber are -1, the pagestore must return last touched (saved) page version with given id.

Specified by:

getPage in interface SecondLevelCacheSessionStore.IPageStore

Returns:

The page

See Also:

SecondLevelCacheSessionStore.IPageStore.getPage(java.lang.String, java.lang.String, int, int, int)

pageAccessed

public void pageAccessed(java.lang.String sessionId,
                         Page page)

Description copied from interface: SecondLevelCacheSessionStore.IPageStore

This method is called when the page is accessed. A IPageStore implementation can block until a save of that page version is done. So that a specific page version is always restore able.

Specified by:

pageAccessed in interface SecondLevelCacheSessionStore.IPageStore

See Also:

SecondLevelCacheSessionStore.IPageStore.pageAccessed(java.lang.String, org.apache.wicket.Page)

removePage

public void removePage(java.lang.String sessionId,
                       java.lang.String pageMap,
                       int id)

Description copied from interface: SecondLevelCacheSessionStore.IPageStore

Removes a page from the persistent layer.

Specified by:

removePage in interface SecondLevelCacheSessionStore.IPageStore

Parameters:

sessionId - The session of the page that must be removed

pageMap - The pagemap of the page that must be removed

id - The id of the page.

See Also:

SecondLevelCacheSessionStore.IPageStore.removePage(java.lang.String, java.lang.String, int)

storeSerializedPages

protected void storeSerializedPages(java.lang.String sessionId,
                                    java.util.List pages)

Stores the serialized pages. The storing is done either immediately (in synchronous mode) or it's scheduled to be stored by the worker thread.

Parameters:

sessionId -

pages -

onPagesSerialized

protected void onPagesSerialized(java.lang.String sessionId,
                                 java.util.List pages)

Hook for processing serialized pages (e.g. sending those across cluster)

Parameters:

sessionId -

pages -

storePage

public void storePage(java.lang.String sessionId,
                      Page page)

Description copied from interface: SecondLevelCacheSessionStore.IPageStore

Stores the page to a persistent layer. The page should be stored under the id and the version number.

Specified by:

storePage in interface SecondLevelCacheSessionStore.IPageStore

See Also:

SecondLevelCacheSessionStore.IPageStore.storePage(java.lang.String, org.apache.wicket.Page)

unbind

public void unbind(java.lang.String sessionId)

Description copied from interface: SecondLevelCacheSessionStore.IPageStore

The pagestore should cleanup all the pages for that sessionid.

Specified by:

unbind in interface SecondLevelCacheSessionStore.IPageStore

See Also:

SecondLevelCacheSessionStore.IPageStore.unbind(java.lang.String)

getPagesToSaveList

protected java.util.List getPagesToSaveList(java.lang.String sessionId)

Returns the list of pages to be saved for the specified session id. If the list is not found, new list is created.

Parameters:

sessionId -

Returns:

flushPagesToSaveList

protected void flushPagesToSaveList(java.lang.String sessionId,
                                    java.util.List list)

Saves all entries from the specified list.

Parameters:

sessionId -

list -

getSavingThreadSleepTime

protected int getSavingThreadSleepTime()

Returns the amount time in milliseconds for the saving thread to sleep between checking whether there are pending serialized pages to be saved.

Returns:

isSynchronous

protected boolean isSynchronous()

Returns whether the DiskPageStore should work in synchronous or asynchronous mode. Asynchronous mode uses a worker thread to save pages, which results in smoother performance.

Returns:

setLastRecentlySerializedPagesCacheSize

public void setLastRecentlySerializedPagesCacheSize(int lastRecentlySerializedPagesCacheSize)

Sets the number of last recently serialized pages kept in cache. The cache is used to aid performance on session replication.

Parameters:

lastRecentlySerializedPagesCacheSize -

getLastRecentlySerializedPagesCacheSize

protected int getLastRecentlySerializedPagesCacheSize()

Returns:

prepareForSerialization

public java.io.Serializable prepareForSerialization(java.lang.String sessionId,
                                                    java.lang.Object page)

Process the page before the it gets serialized. The page can be either real page instance of object returned by SecondLevelCacheSessionStore.ISerializationAwarePageStore.restoreAfterSerialization(Serializable).

Specified by:

prepareForSerialization in interface SecondLevelCacheSessionStore.ISerializationAwarePageStore

Returns:

The Page itself or a SerializedContainer for that page

storeAfterSessionReplication

protected boolean storeAfterSessionReplication()

restoreAfterSerialization

public java.lang.Object restoreAfterSerialization(java.io.Serializable serializable)

Description copied from interface: SecondLevelCacheSessionStore.ISerializationAwarePageStore

This method should restore the serialized page to intermediate object that can be converted to real page instance using SecondLevelCacheSessionStore.ISerializationAwarePageStore.convertToPage(Object).

Specified by:

restoreAfterSerialization in interface SecondLevelCacheSessionStore.ISerializationAwarePageStore

Returns:

Page

See Also:

SecondLevelCacheSessionStore.ISerializationAwarePageStore.restoreAfterSerialization(java.io.Serializable)

convertToPage

public Page convertToPage(java.lang.Object page)

Specified by:

convertToPage in interface SecondLevelCacheSessionStore.ISerializationAwarePageStore

Returns:

containsPage

public boolean containsPage(java.lang.String sessionId,
                            java.lang.String pageMapName,
                            int pageId,
                            int pageVersion)

Description copied from interface: SecondLevelCacheSessionStore.IPageStore

Returns whether the PageStore contains given page.

Specified by:

containsPage in interface SecondLevelCacheSessionStore.IPageStore

Returns:

boolean If the page was found

See Also:

SecondLevelCacheSessionStore.IPageStore.containsPage(java.lang.String, java.lang.String, int, int)