org.jahia.services.render.filter.cache

Class ModuleGeneratorQueue

java.lang.Object

org.jahia.services.render.filter.cache.ModuleGeneratorQueue

All Implemented Interfaces:

org.springframework.beans.factory.InitializingBean

public class ModuleGeneratorQueue
extends Object
implements org.springframework.beans.factory.InitializingBean

Since:

JAHIA 6.5 Created : 12 oct. 2010

Author:

: rincevent

Field Summary

Fields

Modifier and Type	Field and Description
static String	HAS_PROCESSING_SEMAPHORE_PARAM

Constructor Summary

Constructors

Constructor and Description
ModuleGeneratorQueue()

Method Summary

Modifier and Type	Method and Description
void	afterPropertiesSet() Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
Semaphore	getAvailableProcessings() Available processings is a Semaphore that allow multiple threads to generate fragments in parallel the number of parallel processings is configurable using "maxModulesToGenerateInParallel" property
protected void	getFragmentsGenerationPermit(String resourceIdentifier, javax.servlet.http.HttpServletRequest request) Number of threads generating fragments in parallel is limited, this function is used to get the permission to generate a page based on the property "maxModulesToGenerateInParallel".
Map<String,CountDownLatch>	getGeneratingModules()
protected boolean	getLatch(RenderContext renderContext, String finalKey) Get a latch for the given fragment key, this key will be unavailable for all other threads until the thread that put the latch call the releaseLatch function.
int	getMaxModulesToGenerateInParallel()
long	getMinimumIntervalAfterLastAutoThreadDump()
long	getModuleGenerationWaitTime()
Map<String,String>	getNotCacheableModule()
boolean	isThreadDumpToFile()
boolean	isThreadDumpToSystemOut()
protected void	releaseFragmentsGenerationPermit(javax.servlet.http.HttpServletRequest request) Release a permit previously set for the current thread, this function is used when the current thread just finish a page generation.
protected void	releaseLatch(String finalKey) Release latch, this will signal that the current thread have finish its work All the other waiting threads will be free to get/read the resource generated by the first thread This function also handle the maximum allowed fragment generation in parallel internally (based on maxModulesToGenerateInParallel property) The permit is automatically released, no need to do additional call to release the permit.
void	setMaxModulesToGenerateInParallel(int maxModulesToGenerateInParallel)
void	setMinimumIntervalAfterLastAutoThreadDump(long minimumIntervalAfterLastAutoThreadDump)
void	setModuleGenerationWaitTime(long moduleGenerationWaitTime)
void	setThreadDumpToFile(boolean threadDumpToFile)
void	setThreadDumpToSystemOut(boolean threadDumpToSystemOut)

Methods inherited from class java.lang.Object

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

Field Detail

HAS_PROCESSING_SEMAPHORE_PARAM

public static final String HAS_PROCESSING_SEMAPHORE_PARAM

See Also:

Constant Field Values

Constructor Detail

ModuleGeneratorQueue

public ModuleGeneratorQueue()

Method Detail

getNotCacheableModule

public Map<String,String> getNotCacheableModule()

getGeneratingModules

public Map<String,CountDownLatch> getGeneratingModules()

getAvailableProcessings

public Semaphore getAvailableProcessings()

Available processings is a Semaphore that allow multiple threads to generate fragments in parallel the number of parallel processings is configurable using "maxModulesToGenerateInParallel" property

Returns:

the Semaphore

getFragmentsGenerationPermit

protected void getFragmentsGenerationPermit(String resourceIdentifier,
                                            javax.servlet.http.HttpServletRequest request)

Number of threads generating fragments in parallel is limited, this function is used to get the permission to generate a page based on the property "maxModulesToGenerateInParallel". The permit is stored in the current request attributes and must be released when the page is complete by the current thread request using the function "releaseRequestGenerationPermit(HttpServletRequest request)"

Parameters:

resourceIdentifier - Identifier for the current resource, could be the cache key if available, or anything that could identify the resource ( only use for log purpose )

request - the current request

releaseFragmentsGenerationPermit

protected void releaseFragmentsGenerationPermit(javax.servlet.http.HttpServletRequest request)

Release a permit previously set for the current thread, this function is used when the current thread just finish a page generation. A permit slot is released allowing an other thread to take it to generate a fragment.

Parameters:

request - the current request

getLatch

protected boolean getLatch(RenderContext renderContext,
                           String finalKey)
                    throws Exception

Get a latch for the given fragment key, this key will be unavailable for all other threads until the thread that put the latch call the releaseLatch function. The first thread that will call this function will acquire the latch The others threads that call also this "getLatch" fct, coming after will wait until first thread finish his work. The first thread signal that the work is finished by calling the "releaseLatch()" function, This mechanism is used by the CacheFilter to allow first thread to generate a fragment, and other threads wait for it to finished So then can get the generated fragment directly from the cache. By doing that we avoid to generate multiple time the same fragment This function also handle the maximum allowed fragment generation in parallel internally (based on maxModulesToGenerateInParallel property) No need to call the functions to manage the permit of fragment generation additionally to "getLatch" function.

Parameters:

renderContext - current RenderContext

finalKey - fragment key

Returns:

false for first thread or return true for others thread when first thread have released the latch

Throws:

Exception

releaseLatch

protected void releaseLatch(String finalKey)

Release latch, this will signal that the current thread have finish its work All the other waiting threads will be free to get/read the resource generated by the first thread This function also handle the maximum allowed fragment generation in parallel internally (based on maxModulesToGenerateInParallel property) The permit is automatically released, no need to do additional call to release the permit.

getMaxModulesToGenerateInParallel

public int getMaxModulesToGenerateInParallel()

getModuleGenerationWaitTime

public long getModuleGenerationWaitTime()

afterPropertiesSet

public void afterPropertiesSet()
                        throws Exception

Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).

This method allows the bean instance to perform initialization only possible when all bean properties have been set and to throw an exception in the event of misconfiguration.

Specified by:

afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean

Throws:

Exception - in the event of misconfiguration (such as failure to set an essential property) or if initialization fails.

setMaxModulesToGenerateInParallel

public void setMaxModulesToGenerateInParallel(int maxModulesToGenerateInParallel)

setModuleGenerationWaitTime

public void setModuleGenerationWaitTime(long moduleGenerationWaitTime)

setMinimumIntervalAfterLastAutoThreadDump

public void setMinimumIntervalAfterLastAutoThreadDump(long minimumIntervalAfterLastAutoThreadDump)

getMinimumIntervalAfterLastAutoThreadDump

public long getMinimumIntervalAfterLastAutoThreadDump()

isThreadDumpToSystemOut

public boolean isThreadDumpToSystemOut()

setThreadDumpToSystemOut

public void setThreadDumpToSystemOut(boolean threadDumpToSystemOut)

isThreadDumpToFile

public boolean isThreadDumpToFile()

setThreadDumpToFile

public void setThreadDumpToFile(boolean threadDumpToFile)