org.opencms.flex
Class CmsFlexCacheEntry

java.lang.Object
  org.opencms.flex.CmsFlexCacheEntry

All Implemented Interfaces:

I_CmsLruCacheObject, I_CmsMemoryMonitorable

public class CmsFlexCacheEntry
extends java.lang.Object
implements I_CmsLruCacheObject, I_CmsMemoryMonitorable

Contains the contents of a cached resource.

It is basically a list of pre-generated output, include() calls to other resources (with request parameters) and http headers that this resource requires to be set.

A CmsFlexCacheEntry might also describe a redirect-call, but in this case nothing else will be cached.

The pre-generated output is saved in byte[] arrays. The include() calls are saved as Strings of the included resource name, the parameters for the calls are saved in a HashMap. The headers are saved in a HashMap. In case of a redirect, the redirect target is cached in a String.

The CmsFlexCacheEntry can also have an expire date value, which indicates the time that his entry will become invalid and should thus be cleared from the cache.

Since:

6.0.0

Version:

$Revision: 1.37 $

Author:

Alexander Kandzior, Thomas Weckert

See Also:

I_CmsLruCacheObject

Field Summary

static int

INITIAL_CAPACITY_LISTS Initial size for lists.

Constructor Summary

CmsFlexCacheEntry()
Constructor for class CmsFlexCacheEntry.

Method Summary

void	add(byte[] bytes) Adds an array of bytes to this cache entry, this will usually be the result of some kind of output - stream.
void	add(java.lang.String resource, java.util.Map parameters) Add an include - call target resource to this cache entry.
void	addHeaders(java.util.Map headers) Add a map of headers to this cache entry, which are usually collected in the class CmsFlexResponse first.
void	addToLruCache() Invoked after an object was added to the cache.
void	complete() Completes this cache entry.
java.util.List	elements() Returns the list of data entries of this cache entry.
long	getDateExpires() Returns the expiration date of this cache entry, this is set to the time when the entry becomes invalid.
long	getDateLastModified() Returns the "last modified" date for this Flex cache entry.
int	getLruCacheCosts() Returns the cache costs of this object, as for example it's byte size.
int	getMemorySize() Returns the memory size of the object.
I_CmsLruCacheObject	getNextLruObject() Returns the next object in the double linked list of all cached objects.
I_CmsLruCacheObject	getPreviousLruObject() Returns the previous object in the double linked list of all cached objects.
java.lang.Object	getValue() Returns the Object value.
void	removeFromLruCache() Invoked after the object was removed to the cache.
void	service(CmsFlexRequest req, CmsFlexResponse res) Processing method for this cached entry.
void	setDateExpires(long dateExpires) Sets the expiration date of this Flex cache entry exactly to the given time.
void	setDateExpiresToNextTimeout(long timeout) Sets an expiration date for this cache entry to the next timeout, which indicates the time this entry becomes invalid.
void	setDateLastModified(long dateLastModified) Sets the "last modified" date for this Flex cache entry with the given value.
void	setDateLastModifiedToPreviousTimeout(long timeout) Sets the "last modified" date for this Flex cache entry by using the last passed timeout value.
void	setNextLruObject(I_CmsLruCacheObject theNextEntry) Set the next object in the double linked list of all cached objects.
void	setPreviousLruObject(I_CmsLruCacheObject thePreviousEntry) Set the previous object in the double linked list of all cached objects.
void	setRedirect(java.lang.String target) Set a redirect target for this cache entry.
void	setVariationData(java.lang.String theVariationKey, java.util.Map theVariationMap) Stores a backward reference to the map and key where this cache entry is stored.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

INITIAL_CAPACITY_LISTS

public static final int INITIAL_CAPACITY_LISTS

Initial size for lists.

See Also:

Constant Field Values

Constructor Detail

CmsFlexCacheEntry

public CmsFlexCacheEntry()

Constructor for class CmsFlexCacheEntry.

The way to use this class is to first use this empty constructor and later add data with the various add methods.

Method Detail

add

public void add(byte[] bytes)

Adds an array of bytes to this cache entry, this will usually be the result of some kind of output - stream.

Parameters:

bytes - the output to save in the cache

add

public void add(java.lang.String resource,
                java.util.Map parameters)

Add an include - call target resource to this cache entry.

Parameters:

resource - a name of a resource in the OpenCms VFS

parameters - a map of parameters specific to this include call

addHeaders

public void addHeaders(java.util.Map headers)

Add a map of headers to this cache entry, which are usually collected in the class CmsFlexResponse first.

Parameters:

headers - the map of headers to add to the entry

addToLruCache

public void addToLruCache()

Description copied from interface: I_CmsLruCacheObject

Invoked after an object was added to the cache.

Specified by:

addToLruCache in interface I_CmsLruCacheObject

See Also:

I_CmsLruCacheObject.addToLruCache()

complete

public void complete()

Completes this cache entry.

A completed cache entry is made "unmodifiable", so that no further data can be added and existing data can not be changed.

This is to prevent the (unlikely) case that some user-written class tries to make changes to a cache entry.

elements

public java.util.List elements()

Returns the list of data entries of this cache entry.

Data entries are byte arrays representing some kind of output or Strings representing include calls to other resources.

Returns:

the list of data elements of this cache entry

getDateExpires

public long getDateExpires()

Returns the expiration date of this cache entry, this is set to the time when the entry becomes invalid.

Returns:

the expiration date value for this resource

getDateLastModified

public long getDateLastModified()

Returns the "last modified" date for this Flex cache entry.

Returns:

the "last modified" date for this Flex cache entry

getLruCacheCosts

public int getLruCacheCosts()

Description copied from interface: I_CmsLruCacheObject

Returns the cache costs of this object, as for example it's byte size.

Specified by:

getLruCacheCosts in interface I_CmsLruCacheObject

Returns:

the cache costs of this object

See Also:

I_CmsLruCacheObject.getLruCacheCosts()

getMemorySize

public int getMemorySize()

Description copied from interface: I_CmsMemoryMonitorable

Returns the memory size of the object.

Specified by:

getMemorySize in interface I_CmsMemoryMonitorable

Returns:

the memory size of the object

See Also:

I_CmsMemoryMonitorable.getMemorySize()

getNextLruObject

public I_CmsLruCacheObject getNextLruObject()

Description copied from interface: I_CmsLruCacheObject

Returns the next object in the double linked list of all cached objects.

Specified by:

getNextLruObject in interface I_CmsLruCacheObject

Returns:

the next object in the double linked list of all cached objects

See Also:

I_CmsLruCacheObject.getNextLruObject()

getPreviousLruObject

public I_CmsLruCacheObject getPreviousLruObject()

Description copied from interface: I_CmsLruCacheObject

Returns the previous object in the double linked list of all cached objects.

Specified by:

getPreviousLruObject in interface I_CmsLruCacheObject

Returns:

the previous object in the double linked list of all cached objects

See Also:

I_CmsLruCacheObject.getPreviousLruObject()

getValue

public java.lang.Object getValue()

Description copied from interface: I_CmsLruCacheObject

Returns the Object value.

Specified by:

getValue in interface I_CmsLruCacheObject

Returns:

the Object value

See Also:

I_CmsLruCacheObject.getValue()

removeFromLruCache

public void removeFromLruCache()

Description copied from interface: I_CmsLruCacheObject

Invoked after the object was removed to the cache.

Specified by:

removeFromLruCache in interface I_CmsLruCacheObject

See Also:

I_CmsLruCacheObject.removeFromLruCache()

service

public void service(CmsFlexRequest req,
                    CmsFlexResponse res)
             throws CmsFlexCacheException,
                    javax.servlet.ServletException,
                    java.io.IOException

Processing method for this cached entry.

If this method is called, it delivers the contents of the cached entry to the given request / response. This includes calls to all included resources.

Parameters:

req - the request from the client

res - the server response

Throws:

CmsFlexCacheException - is thrown when problems writing to the response output-stream occur

javax.servlet.ServletException - might be thrown from call to RequestDispatcher.include()

java.io.IOException - might be thrown from call to RequestDispatcher.include() or from Response.sendRedirect()

setDateExpires

public void setDateExpires(long dateExpires)

Sets the expiration date of this Flex cache entry exactly to the given time.

Parameters:

dateExpires - the time to expire this cache entry

setDateExpiresToNextTimeout

public void setDateExpiresToNextTimeout(long timeout)

Sets an expiration date for this cache entry to the next timeout, which indicates the time this entry becomes invalid.

The timeout parameter represents the minute - interval in which the cache entry is to be cleared. The interval always starts at 0.00h. A value of 60 would indicate that this entry will reach it's expiration date at the beginning of the next full hour, a timeout of 20 would indicate that the entry is invalidated at x.00, x.20 and x.40 of every hour etc.

Parameters:

timeout - the timeout value to be set

setDateLastModified

public void setDateLastModified(long dateLastModified)

Sets the "last modified" date for this Flex cache entry with the given value.

Parameters:

dateLastModified - the value to set for the "last modified" date

setDateLastModifiedToPreviousTimeout

public void setDateLastModifiedToPreviousTimeout(long timeout)

Sets the "last modified" date for this Flex cache entry by using the last passed timeout value.

If a cache entry uses the timeout feature, it becomes invalid every time the timeout interval passes. Thus the "last modified" date is the time the last timeout passed.

Parameters:

timeout - the timeout value to use to calculate the date last modified

setNextLruObject

public void setNextLruObject(I_CmsLruCacheObject theNextEntry)

Description copied from interface: I_CmsLruCacheObject

Set the next object in the double linked list of all cached objects.

Specified by:

setNextLruObject in interface I_CmsLruCacheObject

Parameters:

theNextEntry - the next object

See Also:

I_CmsLruCacheObject.setNextLruObject(org.opencms.cache.I_CmsLruCacheObject)

setPreviousLruObject

public void setPreviousLruObject(I_CmsLruCacheObject thePreviousEntry)

Description copied from interface: I_CmsLruCacheObject

Set the previous object in the double linked list of all cached objects.

Specified by:

setPreviousLruObject in interface I_CmsLruCacheObject

Parameters:

thePreviousEntry - the previous object

See Also:

I_CmsLruCacheObject.setPreviousLruObject(org.opencms.cache.I_CmsLruCacheObject)

setRedirect

public void setRedirect(java.lang.String target)

Set a redirect target for this cache entry.

Important: When a redirect target is set, all saved data is thrown away, and new data will not be saved in the cache entry. This is so since with a redirect nothing will be displayed in the browser anyway, so there is no point in saving the data.

Parameters:

target - The redirect target (must be a valid URL).

setVariationData

public void setVariationData(java.lang.String theVariationKey,
                             java.util.Map theVariationMap)

Stores a backward reference to the map and key where this cache entry is stored.

This is required for the FlexCache.

Parameters:

theVariationKey - the variation key

theVariationMap - the variation map

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

a basic String representation of this CmsFlexCache entry

See Also:

Object.toString()