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org.apache.cocoon.components.source.impl
Class CachingSourceFactory

java.lang.Object
  org.apache.avalon.framework.logger.AbstractLogEnabled
      org.apache.cocoon.components.source.impl.CachingSourceFactory

All Implemented Interfaces:

Disposable, Configurable, LogEnabled, Serviceable, ThreadSafe, SourceFactory, URIAbsolutizer

public class CachingSourceFactory
extends AbstractLogEnabled
implements Serviceable, Configurable, Disposable, ThreadSafe, URIAbsolutizer, SourceFactory

This class implements a proxy like source caches the contents of the source it wraps. This implementation can cache the content either for a given period of time or until an external event invalidates the cached response.

When using the timeout approach you have a choice between two separate revalidation strategies:

• Synchronously. This means that the cached contents are checked for validity and thrown out on the current thread.
• Asynchronously. A runnable task is created to invalidate and update the cached response in the backgound.

Protocol syntax

The URL needs to contain the URL of the cached source, an expiration period in seconds, and optionally a cache key: cached:http://www.apache.org/[?cocoon:cache-expires=60][&cocoon:cache-name=main].

The above examples shows how the real source http://www.apache.org/ is wrapped and the cached contents is used for 60 seconds. The second querystring parameter instructs that the cache key be extended with the string main. This allows the use of multiple cache entries for the same source.

This factory creates either instances of CachingSource or TraversableCachingSource depending on the whether the wrapped Source is an instance of TraversableSource.

Parameters

cache-role (String)	Role of component used as cache.	opt	String	Cache.ROLE
refresher-role (String)	Role of component used for refreshing sources.	opt	String	SourceRefresher.ROLE
async (boolean)	Indicated if the cached source should be refreshed asynchronously.	opt	String	false
event-aware (boolean)	Whether to use event-based cache invalidation.	opt	String	false
default-expires (int)	Default expiration value for if it is not specified on the Source itself.	opt	String	-1

Since:

2.1.1

Version:

$Id: CachingSourceFactory.html 1304258 2012-03-23 10:09:27Z ilgrosso $

Field Summary

protected Cache	cache The cache
protected ServiceManager	manager The ServiceManager
protected SourceRefresher	refresher The refresher
protected SourceResolver	resolver The SourceResolver

Fields inherited from interface org.apache.excalibur.source.SourceFactory

ROLE

Constructor Summary

CachingSourceFactory()

Method Summary

String	absolutize(String baseURI, String location)
void	configure(Configuration configuration)
protected CachingSource	createCachingSource(String uri, String wrappedUri, Source wrappedSource, int expires, String cacheName) Actually creates a new CachingSource.
void	dispose()
protected String	getScheme()
Source	getSource(String location, Map parameters) Get a Source object.
protected boolean	isAsync()
void	release(Source source) Release a Source object.
void	service(ServiceManager manager)

Methods inherited from class org.apache.avalon.framework.logger.AbstractLogEnabled

enableLogging, getLogger, setupLogger, setupLogger, setupLogger

Methods inherited from class java.lang.Object

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

Field Detail

manager

protected ServiceManager manager

The ServiceManager

resolver

protected SourceResolver resolver

The SourceResolver

refresher

protected SourceRefresher refresher

The refresher

cache

protected Cache cache

The cache

Constructor Detail

CachingSourceFactory

public CachingSourceFactory()

Method Detail

service

public void service(ServiceManager manager)

Specified by:

service in interface Serviceable

configure

public void configure(Configuration configuration)
               throws ConfigurationException

Specified by:

configure in interface Configurable

Throws:

ConfigurationException

dispose

public void dispose()

Specified by:

dispose in interface Disposable

getScheme

protected String getScheme()

isAsync

protected boolean isAsync()

getSource

public Source getSource(String location,
                        Map parameters)
                 throws MalformedURLException,
                        IOException

Get a Source object.

Specified by:

getSource in interface SourceFactory

Parameters:

parameters - This is optional.

Throws:

MalformedURLException

IOException

createCachingSource

protected CachingSource createCachingSource(String uri,
                                            String wrappedUri,
                                            Source wrappedSource,
                                            int expires,
                                            String cacheName)
                                     throws SourceException

Actually creates a new CachingSource. Can be overriden in subclasses

Throws:

SourceException

release

public void release(Source source)

Release a Source object.

Specified by:

release in interface SourceFactory

absolutize

public String absolutize(String baseURI,
                         String location)

Specified by:

absolutize in interface URIAbsolutizer