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ACE_LFU_Caching_Strategy Class Template Reference

Defines a Least Frequently Used strategy for which will decide on the item to be removed from the cache. More...

#include <Caching_Strategies_T.h>

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Public Types

typedef ATTRIBUTES CACHING_ATTRIBUTES

Public Methods

 ACE_LFU_Caching_Strategy (void)
ATTRIBUTES attributes (void)
 Access the attributes. More...

double purge_percent (void)
 Get the percentage of entries to purge. More...

void purge_percent (double percentage)
 Set the percentage of entries to purge. More...

int notify_bind (int result, const ATTRIBUTES &attr)
 This method acts as a notification about the CONTAINERs bind method call. More...

int notify_find (int result, ATTRIBUTES &attr)
 Lookup notification. More...

int notify_unbind (int result, const ATTRIBUTES &attr)
 This method acts as a notification about the CONTAINERs unbind method call. More...

int notify_trybind (int result, ATTRIBUTES &attr)
 This method acts as a notification about the CONTAINERs trybind method call. More...

int notify_rebind (int result, const ATTRIBUTES &attr)
 This method acts as a notification about the CONTAINERs rebind method call. More...

CACHING_UTILITY & caching_utility (void)
 Purge the cache. More...

void dump (void) const
 Dumps the state of the object. More...


Private Attributes

double purge_percent_
 The level about which the purging will happen automagically. More...

CACHING_UTILITY caching_utility_
 This is the helper class which will decide and expunge entries from the cache. More...


Detailed Description

template<class ATTRIBUTES, class CACHING_UTILITY>
class ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >

Defines a Least Frequently Used strategy for which will decide on the item to be removed from the cache.

A attribute is tagged to each item which increments whenever the item is bound or looked up in the cache. Thus it denotes the frequency of use. According to the value of the attribute the item is removed from the CONTAINER i.e cache. Explanation of the template parameter list: CONTAINER is any map with entries of type <KEY, VALUE>. The ATTRIBUTES are the deciding factor for purging of entries and should logically be included with the VALUE. Some ways of doing this are: As being a member of the VALUE or VALUE being ACE_Pair<x, ATTRIBUTES>. The CACHING_UTILITY is the class which can be plugged in and which decides the entries to purge.

Definition at line 297 of file Caching_Strategies_T.h.


Member Typedef Documentation

template<class ATTRIBUTES, class CACHING_UTILITY>
typedef ATTRIBUTES ACE_LFU_Caching_Strategy::CACHING_ATTRIBUTES
 

Definition at line 303 of file Caching_Strategies_T.h.


Constructor & Destructor Documentation

template<class ATTRIBUTES, class CACHING_UTILITY>
ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::ACE_LFU_Caching_Strategy void   
 

The <container> is the map in which the entries reside. The timer attribute is initialed to zero in this constructor. And the <purge_percent> field denotes the percentage of the entries in the cache which can be purged automagically and by default is set to 10%.

Definition at line 36 of file Caching_Strategies_T.cpp.

00037   : purge_percent_ (10)
00038 {
00039 }


Member Function Documentation

template<class ATTRIBUTES, class CACHING_UTILITY>
ACE_INLINE ATTRIBUTES ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::attributes void   
 

Access the attributes.

Definition at line 203 of file Caching_Strategies_T.i.

00204 {
00205   return 0;
00206 }

template<class ATTRIBUTES, class CACHING_UTILITY>
ACE_INLINE CACHING_UTILITY & ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::caching_utility void   
 

Purge the cache.

Definition at line 267 of file Caching_Strategies_T.i.

References caching_utility_.

00268 {
00269   return this->caching_utility_;
00270 }

template<class ATTRIBUTES, class CACHING_UTILITY>
ACE_INLINE void ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::dump void    const
 

Dumps the state of the object.

Definition at line 273 of file Caching_Strategies_T.i.

References ACE_BEGIN_DUMP, ACE_DEBUG, ACE_END_DUMP, ACE_TRACE, and LM_DEBUG.

00274 {
00275   ACE_TRACE ("ACE_LFU_Caching_Strategy::dump");
00276 
00277   ACE_DEBUG ((LM_DEBUG, ACE_BEGIN_DUMP, this));
00278   ACE_DEBUG ((LM_DEBUG, ACE_END_DUMP));
00279 }

template<class ATTRIBUTES, class CACHING_UTILITY>
ACE_INLINE int ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::notify_bind int    result,
const ATTRIBUTES &    attr
 

This method acts as a notification about the CONTAINERs bind method call.

Definition at line 221 of file Caching_Strategies_T.i.

00223 {
00224   ACE_UNUSED_ARG (attr);
00225 
00226   return result;
00227 }

template<class ATTRIBUTES, class CACHING_UTILITY>
ACE_INLINE int ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::notify_find int    result,
ATTRIBUTES &    attr
 

Lookup notification.

Definition at line 230 of file Caching_Strategies_T.i.

00232 {
00233   if (result == 0)
00234     ++attr;
00235 
00236   return result;
00237 }

template<class ATTRIBUTES, class CACHING_UTILITY>
ACE_INLINE int ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::notify_rebind int    result,
const ATTRIBUTES &    attr
 

This method acts as a notification about the CONTAINERs rebind method call.

Definition at line 249 of file Caching_Strategies_T.i.

00251 {
00252   ACE_UNUSED_ARG (attr);
00253 
00254   return result;
00255 }

template<class ATTRIBUTES, class CACHING_UTILITY>
ACE_INLINE int ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::notify_trybind int    result,
ATTRIBUTES &    attr
 

This method acts as a notification about the CONTAINERs trybind method call.

Definition at line 240 of file Caching_Strategies_T.i.

00242 {
00243   ACE_UNUSED_ARG (attr);
00244 
00245   return result;
00246 }

template<class ATTRIBUTES, class CACHING_UTILITY>
ACE_INLINE int ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::notify_unbind int    result,
const ATTRIBUTES &    attr
 

This method acts as a notification about the CONTAINERs unbind method call.

Definition at line 258 of file Caching_Strategies_T.i.

00260 {
00261   ACE_UNUSED_ARG (attr);
00262 
00263   return result;
00264 }

template<class ATTRIBUTES, class CACHING_UTILITY>
ACE_INLINE void ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::purge_percent double    percentage
 

Set the percentage of entries to purge.

Definition at line 215 of file Caching_Strategies_T.i.

References purge_percent_.

00216 {
00217   this->purge_percent_ = percentage;
00218 }

template<class ATTRIBUTES, class CACHING_UTILITY>
ACE_INLINE double ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::purge_percent void   
 

Get the percentage of entries to purge.

Definition at line 209 of file Caching_Strategies_T.i.

References purge_percent_.

00210 {
00211   return this->purge_percent_;
00212 }


Member Data Documentation

template<class ATTRIBUTES, class CACHING_UTILITY>
CACHING_UTILITY ACE_LFU_Caching_Strategy::caching_utility_ [private]
 

This is the helper class which will decide and expunge entries from the cache.

Definition at line 366 of file Caching_Strategies_T.h.

Referenced by caching_utility.

template<class ATTRIBUTES, class CACHING_UTILITY>
double ACE_LFU_Caching_Strategy::purge_percent_ [private]
 

The level about which the purging will happen automagically.

Definition at line 362 of file Caching_Strategies_T.h.

Referenced by purge_percent.


The documentation for this class was generated from the following files:
Generated on Mon Jun 16 12:49:11 2003 for ACE by doxygen1.2.14 written by Dimitri van Heesch, © 1997-2002