Module org.eclipse.jetty.session

Package org.eclipse.jetty.session

Class CachingSessionDataStore

java.lang.Object

org.eclipse.jetty.util.component.AbstractLifeCycle

org.eclipse.jetty.util.component.ContainerLifeCycle

org.eclipse.jetty.session.CachingSessionDataStore

All Implemented Interfaces:

SessionDataMap, SessionDataStore, org.eclipse.jetty.util.component.Container, org.eclipse.jetty.util.component.Destroyable, org.eclipse.jetty.util.component.Dumpable, org.eclipse.jetty.util.component.Dumpable.DumpableContainer, org.eclipse.jetty.util.component.LifeCycle

public class CachingSessionDataStore
extends org.eclipse.jetty.util.component.ContainerLifeCycle
implements SessionDataStore

A SessionDataStore is a mechanism for (persistently) storing data associated with sessions. This implementation delegates to a pluggable SessionDataStore for actually storing the session data. It also uses a pluggable cache implementation in front of the delegate SessionDataStore to improve performance: accessing most persistent store technology can be expensive time-wise, so introducing a fronting cache can increase performance. The cache implementation can either be a local cache, a remote cache, or a clustered cache.

The implementation here will try to read first from the cache and fallback to reading from the SessionDataStore if the session key is not found. On writes, the session data is written first to the SessionDataStore, and then to the cache. On deletes, the data is deleted first from the SessionDataStore, and then from the cache. There is no transaction manager ensuring atomic operations, so it is possible that failures can result in cache inconsistency.

Nested Class Summary

Nested classes/interfaces inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle

org.eclipse.jetty.util.component.AbstractLifeCycle.AbstractLifeCycleListener, org.eclipse.jetty.util.component.AbstractLifeCycle.StopException

Nested classes/interfaces inherited from interface org.eclipse.jetty.util.component.Container

org.eclipse.jetty.util.component.Container.InheritedListener, org.eclipse.jetty.util.component.Container.Listener

Nested classes/interfaces inherited from interface org.eclipse.jetty.util.component.Dumpable

org.eclipse.jetty.util.component.Dumpable.DumpableContainer, org.eclipse.jetty.util.component.Dumpable.DumpAppendable

Nested classes/interfaces inherited from interface org.eclipse.jetty.util.component.LifeCycle

org.eclipse.jetty.util.component.LifeCycle.Listener

Field Summary

Fields

Modifier and Type	Field	Description
protected SessionDataMap	_cache	The fronting cache
protected SessionDataStore	_store	The actual store for the session data

Fields inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle

FAILED, STARTED, STARTING, STOPPED, STOPPING

Fields inherited from interface org.eclipse.jetty.util.component.Dumpable

LEGEND

Constructor Summary

Constructors

Constructor	Description
CachingSessionDataStore(SessionDataMap cache, SessionDataStore store)

Method Summary

Modifier and Type	Method	Description
boolean	delete(String id)	Delete session data
protected void	doStart()
protected void	doStop()
boolean	exists(String id)	Test if data exists for a given session id.
Set<String>	getExpired(Set<String> candidates)	Called periodically, this method should search the data store for sessions that have been expired for a 'reasonable' amount of time.
SessionDataMap	getSessionDataMap()	Get the fronting cache for session data.
SessionDataStore	getSessionStore()	Get the delegate session store.
void	initialize(SessionContext context)	Initialize this data map for the given context.
boolean	isPassivating()	True if this type of datastore will passivate session objects
SessionData	load(String id)	Read in session data.
SessionData	newSessionData(String id, long created, long accessed, long lastAccessed, long maxInactiveMs)	Create a new SessionData
void	store(String id, SessionData data)	Store the session data.

Methods inherited from class org.eclipse.jetty.util.component.ContainerLifeCycle

addBean, addBean, addEventListener, addManaged, contains, destroy, dump, dump, dump, dumpObjects, dumpStdErr, getBean, getBeans, getBeans, getContainedBeans, getContainedBeans, installBean, installBean, isAuto, isManaged, isUnmanaged, manage, removeBean, removeBeans, removeEventListener, setBeans, start, stop, unmanage, updateBean, updateBean, updateBeans, updateBeans

Methods inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle

getEventListeners, getState, getState, isFailed, isRunning, isStarted, isStarting, isStopped, isStopping, setEventListeners, start, stop, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.jetty.util.component.Container

getCachedBeans, getEventListeners

Methods inherited from interface org.eclipse.jetty.util.component.Dumpable

dumpSelf

Methods inherited from interface org.eclipse.jetty.util.component.Dumpable.DumpableContainer

isDumpable

Methods inherited from interface org.eclipse.jetty.util.component.LifeCycle

addEventListener, isFailed, isRunning, isStarted, isStarting, isStopped, isStopping, removeEventListener, start, stop

Field Details

_store

protected SessionDataStore _store

The actual store for the session data

_cache

protected SessionDataMap _cache

The fronting cache

Constructor Details

CachingSessionDataStore

public CachingSessionDataStore(SessionDataMap cache,
 SessionDataStore store)

Parameters:

cache - the front cache to use

store - the actual store for the session data

Method Details

getSessionStore

public SessionDataStore getSessionStore()

Get the delegate session store.

Returns:

the delegate session store

getSessionDataMap

public SessionDataMap getSessionDataMap()

Get the fronting cache for session data.

Returns:

the fronting cache for session data

load

public SessionData load(String id)
                 throws Exception

Description copied from interface: SessionDataMap

Read in session data.

Specified by:

load in interface SessionDataMap

Parameters:

id - identity of session to load

Returns:

the SessionData matching the id

Throws:

Exception - if unable to load session data

delete

public boolean delete(String id)
               throws Exception

Description copied from interface: SessionDataMap

Delete session data

Specified by:

delete in interface SessionDataMap

Parameters:

id - identity of session to delete

Returns:

true if the session was deleted

Throws:

Exception - if unable to delete session data

getExpired

public Set<String> getExpired(Set<String> candidates)

Description copied from interface: SessionDataStore

Called periodically, this method should search the data store for sessions that have been expired for a 'reasonable' amount of time.

Specified by:

getExpired in interface SessionDataStore

Parameters:

candidates - if provided, these are keys of sessions that the SessionDataStore thinks has expired and should be verified by the SessionDataStore

Returns:

set of session ids

store

public void store(String id,
 SessionData data)
           throws Exception

Description copied from interface: SessionDataMap

Store the session data.

Specified by:

store in interface SessionDataMap

Parameters:

id - identity of session to store

data - info of session to store

Throws:

Exception - if unable to write session data

doStart

protected void doStart()
                throws Exception

Overrides:

doStart in class org.eclipse.jetty.util.component.ContainerLifeCycle

Throws:

Exception

doStop

protected void doStop()
               throws Exception

Overrides:

doStop in class org.eclipse.jetty.util.component.ContainerLifeCycle

Throws:

Exception

isPassivating

public boolean isPassivating()

Description copied from interface: SessionDataStore

True if this type of datastore will passivate session objects

Specified by:

isPassivating in interface SessionDataStore

Returns:

true if this store can passivate sessions, false otherwise

exists

public boolean exists(String id)
               throws Exception

Description copied from interface: SessionDataStore

Test if data exists for a given session id.

Specified by:

exists in interface SessionDataStore

Parameters:

id - Identity of session whose existence should be checked

Returns:

true if valid, non-expired session exists

Throws:

Exception - if problem checking existence with persistence layer

initialize

public void initialize(SessionContext context)
                throws Exception

Description copied from interface: SessionDataMap

Initialize this data map for the given context. A SessionDataMap can only be used by one context(/session manager).

Specified by:

initialize in interface SessionDataMap

Parameters:

context - context associated

Throws:

Exception - if unable to initialize the

newSessionData

public SessionData newSessionData(String id,
 long created,
 long accessed,
 long lastAccessed,
 long maxInactiveMs)

Description copied from interface: SessionDataStore

Create a new SessionData

Specified by:

newSessionData in interface SessionDataStore

Parameters:

id - the id

created - the timestamp when created

accessed - the timestamp when accessed

lastAccessed - the timestamp when last accessed

maxInactiveMs - the max inactive time in milliseconds

Returns:

a new SessionData object