org.apache.cocoon.components.flow
Class ContinuationsManagerImpl

java.lang.Object
  org.apache.cocoon.util.AbstractLogEnabled
      org.apache.cocoon.components.flow.ContinuationsManagerImpl

All Implemented Interfaces:

Configurable, Contextualizable, org.apache.cocoon.components.flow.ContinuationsManager, Serviceable, ThreadSafe

public class ContinuationsManagerImpl

extends org.apache.cocoon.util.AbstractLogEnabled

implements org.apache.cocoon.components.flow.ContinuationsManager, Configurable, ThreadSafe, Serviceable, Contextualizable

The default implementation of ContinuationsManager.
There are two modes of work:

• standard mode - continuations are stored in single holder. No security is applied to continuation lookup. Anyone can invoke a continuation only knowing the ID. Set "session-bound-continuations" configuration option to false to activate this mode.
• secure mode - each session has it's own continuations holder. A continuation is only valid for the same session it was created for. Session invalidation causes all bound continuations to be invalidated as well. Use this setting for web applications. Set "session-bound-continuations" configuration option to true to activate this mode.

Since:

March 19, 2002

Version:

$Id: ContinuationsManagerImpl.html 1304280 2012-03-23 11:18:01Z ilgrosso $

See Also:

ContinuationsManager

Nested Class Summary

protected class	ContinuationsManagerImpl.HolderAwareWebContinuation WebContinuation extension that holds also the information about the holder.
class	ContinuationsManagerImpl.WebContinuationsHolder A holder for WebContinuations.

Field Summary

protected boolean	bindContinuationsToSession
protected byte[]	bytes
protected Context	context
protected ContinuationsManagerImpl.WebContinuationsHolder	continuationsHolder Main continuations holder.
protected int	defaultTimeToLive How long does a continuation exist in memory since the last access? The time is in miliseconds, and the default is 1 hour.
protected long	expirationCheckInterval
protected SortedSet	expirations Sorted set of WebContinuation instances, based on their expiration time.
protected Set	forest Maintains the forest of WebContinuation trees.
protected SecureRandom	random Random number generator used to create continuation ID
protected ServiceManager	serviceManager

Fields inherited from interface org.apache.cocoon.components.flow.ContinuationsManager

ROLE

Constructor Summary

ContinuationsManagerImpl()

Method Summary

protected void	_detach(org.apache.cocoon.components.flow.WebContinuation wk) Detach this continuation from parent.
void	configure(Configuration config)
void	contextualize(Context context)
org.apache.cocoon.components.flow.WebContinuation	createWebContinuation(Object kont, org.apache.cocoon.components.flow.WebContinuation parent, int timeToLive, String interpreterId, org.apache.cocoon.components.flow.ContinuationsDisposer disposer)
void	displayAllContinuations() Dump to Log file all WebContinuations in the system
protected void	displayExpireSet() Dump to Log file the current contents of the expirations SortedSet
protected void	disposeContinuation(ContinuationsManagerImpl.WebContinuationsHolder continuationsHolder, org.apache.cocoon.components.flow.WebContinuation wk) Makes the continuation inaccessible for lookup, and triggers possible needed cleanup code through the ContinuationsDisposer interface.
protected void	expireContinuations() Remove all continuations which have already expired.
protected org.apache.cocoon.components.flow.WebContinuation	generateContinuation(Object kont, org.apache.cocoon.components.flow.WebContinuation parent, int ttl, String interpreterId, org.apache.cocoon.components.flow.ContinuationsDisposer disposer) Create WebContinuation and generate unique identifier for it.
List	getWebContinuationsDataBeanList() Get a list of all web continuations (data only)
protected void	handleLeafContinuationExpiration(org.apache.cocoon.components.flow.WebContinuation wk) When a new continuation is created in @link #createWebContinuation(Object, WebContinuation, int, String, ContinuationsDisposer), it is registered in the expiration set in order to be evaluated by the invalidation mechanism.
protected void	handleParentContinuationExpiration(org.apache.cocoon.components.flow.WebContinuation parent) When a new continuation is created in @link #createWebContinuation(Object, WebContinuation, int, String, ContinuationsDisposer), its parent continuation is removed from the expiration set.
protected void	invalidateContinuations(ContinuationsManagerImpl.WebContinuationsHolder continuationsHolder) Method used by WebContinuationsHolder to notify the continuations manager about session invalidation.
void	invalidateWebContinuation(org.apache.cocoon.components.flow.WebContinuation wk)
org.apache.cocoon.components.flow.WebContinuation	lookupWebContinuation(String id, String interpreterId)
ContinuationsManagerImpl.WebContinuationsHolder	lookupWebContinuationsHolder(boolean createNew) Lookup a proper web continuations holder.
protected void	removeContinuation(ContinuationsManagerImpl.WebContinuationsHolder continuationsHolder, org.apache.cocoon.components.flow.WebContinuation wk) Removes an expired leaf WebContinuation node from its continuation tree, and recursively removes its parent(s) if it they have expired and have no (other) children.
void	service(ServiceManager manager)

Methods inherited from class org.apache.cocoon.util.AbstractLogEnabled

getLogger, setLogger

Methods inherited from class java.lang.Object

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

Field Detail

random

protected SecureRandom random

Random number generator used to create continuation ID

bytes

protected byte[] bytes

defaultTimeToLive

protected int defaultTimeToLive

How long does a continuation exist in memory since the last access? The time is in miliseconds, and the default is 1 hour.

forest

protected Set forest

Maintains the forest of WebContinuation trees. This set is used only for debugging puroses by displayAllContinuations() method.

continuationsHolder

protected ContinuationsManagerImpl.WebContinuationsHolder continuationsHolder

Main continuations holder. Used unless continuations are stored in user session.

expirations

protected SortedSet expirations

Sorted set of WebContinuation instances, based on their expiration time. This is used by the background thread to invalidate continuations.

bindContinuationsToSession

protected boolean bindContinuationsToSession

serviceManager

protected ServiceManager serviceManager

context

protected Context context

expirationCheckInterval

protected long expirationCheckInterval

Constructor Detail

ContinuationsManagerImpl

public ContinuationsManagerImpl()
                         throws Exception

Method Detail

service

public void service(ServiceManager manager)
             throws ServiceException

Specified by:

service in interface Serviceable

Throws:

ServiceException

configure

public void configure(Configuration config)

Specified by:

configure in interface Configurable

createWebContinuation

public org.apache.cocoon.components.flow.WebContinuation createWebContinuation(Object kont,
                                                                               org.apache.cocoon.components.flow.WebContinuation parent,
                                                                               int timeToLive,
                                                                               String interpreterId,
                                                                               org.apache.cocoon.components.flow.ContinuationsDisposer disposer)

Specified by:

createWebContinuation in interface org.apache.cocoon.components.flow.ContinuationsManager

handleLeafContinuationExpiration

protected void handleLeafContinuationExpiration(org.apache.cocoon.components.flow.WebContinuation wk)

When a new continuation is created in @link #createWebContinuation(Object, WebContinuation, int, String, ContinuationsDisposer), it is registered in the expiration set in order to be evaluated by the invalidation mechanism.

handleParentContinuationExpiration

protected void handleParentContinuationExpiration(org.apache.cocoon.components.flow.WebContinuation parent)

When a new continuation is created in @link #createWebContinuation(Object, WebContinuation, int, String, ContinuationsDisposer), its parent continuation is removed from the expiration set. This way only leaf continuations are part of the expiration set.

getWebContinuationsDataBeanList

public List getWebContinuationsDataBeanList()

Get a list of all web continuations (data only)

Specified by:

getWebContinuationsDataBeanList in interface org.apache.cocoon.components.flow.ContinuationsManager

lookupWebContinuation

public org.apache.cocoon.components.flow.WebContinuation lookupWebContinuation(String id,
                                                                               String interpreterId)

Specified by:

lookupWebContinuation in interface org.apache.cocoon.components.flow.ContinuationsManager

generateContinuation

protected org.apache.cocoon.components.flow.WebContinuation generateContinuation(Object kont,
                                                                                 org.apache.cocoon.components.flow.WebContinuation parent,
                                                                                 int ttl,
                                                                                 String interpreterId,
                                                                                 org.apache.cocoon.components.flow.ContinuationsDisposer disposer)

Create WebContinuation and generate unique identifier for it. The identifier is generated using a cryptographically strong algorithm to prevent people to generate their own identifiers.

It has the side effect of interning the continuation object in the idToWebCont hash table.

Parameters:

kont - an Object value representing continuation

parent - value representing parent WebContinuation

ttl - WebContinuation time to live

interpreterId - id of interpreter invoking continuation creation

disposer - ContinuationsDisposer instance to use for cleanup of the continuation.

Returns:

the generated WebContinuation with unique identifier

invalidateWebContinuation

public void invalidateWebContinuation(org.apache.cocoon.components.flow.WebContinuation wk)

Specified by:

invalidateWebContinuation in interface org.apache.cocoon.components.flow.ContinuationsManager

_detach

protected void _detach(org.apache.cocoon.components.flow.WebContinuation wk)

Detach this continuation from parent. This method removes continuation from forest set, or, if it has parent, from parent's children collection.

Parameters:

wk - Continuation to detach from parent.

disposeContinuation

protected void disposeContinuation(ContinuationsManagerImpl.WebContinuationsHolder continuationsHolder,
                                   org.apache.cocoon.components.flow.WebContinuation wk)

Makes the continuation inaccessible for lookup, and triggers possible needed cleanup code through the ContinuationsDisposer interface.

Parameters:

continuationsHolder -

wk - the continuation to dispose.

removeContinuation

protected void removeContinuation(ContinuationsManagerImpl.WebContinuationsHolder continuationsHolder,
                                  org.apache.cocoon.components.flow.WebContinuation wk)

Removes an expired leaf WebContinuation node from its continuation tree, and recursively removes its parent(s) if it they have expired and have no (other) children.

Parameters:

continuationsHolder -

wk - WebContinuation node

displayExpireSet

protected void displayExpireSet()

Dump to Log file the current contents of the expirations SortedSet

displayAllContinuations

public void displayAllContinuations()

Dump to Log file all WebContinuations in the system

Specified by:

displayAllContinuations in interface org.apache.cocoon.components.flow.ContinuationsManager

expireContinuations

protected void expireContinuations()

Remove all continuations which have already expired.

invalidateContinuations

protected void invalidateContinuations(ContinuationsManagerImpl.WebContinuationsHolder continuationsHolder)

Method used by WebContinuationsHolder to notify the continuations manager about session invalidation. Invalidates all continuations held by passed continuationsHolder.

lookupWebContinuationsHolder

public ContinuationsManagerImpl.WebContinuationsHolder lookupWebContinuationsHolder(boolean createNew)

Lookup a proper web continuations holder.

Parameters:

createNew - should the manager create a continuations holder in session when none found?

contextualize

public void contextualize(Context context)
                   throws ContextException

Specified by:

contextualize in interface Contextualizable

Throws:

ContextException