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ACE_LFU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY > 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 Member Functions

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

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

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

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

int notify_unbind (int result, const ATTRIBUTES &attr)
int notify_trybind (int result, ATTRIBUTES &attr)
int notify_rebind (int result, const ATTRIBUTES &attr)
CACHING_UTILITY & caching_utility (void)
 Purge the cache.

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


Private Attributes

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

CACHING_UTILITY caching_utility_

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 299 of file Caching_Strategies_T.h.

Member Typedef Documentation

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

Definition at line 305 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 is the map in which the entries reside. The timer attribute is initialed to zero in this constructor. And the 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 210 of file Caching_Strategies_T.inl. 

00211 {
00212   return 0;
00213 }

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.inl. 

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.inl.

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

00274 {
00275 #if defined (ACE_HAS_DUMP)
00276   ACE_TRACE ("ACE_LFU_Caching_Strategy::dump");
00277 
00278   ACE_DEBUG ((LM_DEBUG, ACE_BEGIN_DUMP, this));
00279   ACE_DEBUG ((LM_DEBUG, ACE_END_DUMP));
00280 #endif /* ACE_HAS_DUMP */
00281 }

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 228 of file Caching_Strategies_T.inl. 

00230 {
00231 
00232   return result;
00233 }

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 236 of file Caching_Strategies_T.inl. 

00238 {
00239   if (result == 0)
00240     ++attr;
00241 
00242   return result;
00243 }

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 253 of file Caching_Strategies_T.inl. 

00255 {
00256   return result;
00257 }

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 246 of file Caching_Strategies_T.inl. 

00248 {
00249   return result;
00250 }

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 260 of file Caching_Strategies_T.inl. 

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 222 of file Caching_Strategies_T.inl. 

00223 {
00224   this->purge_percent_ = percentage;
00225 }

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 216 of file Caching_Strategies_T.inl. 

00217 {
00218   return this->purge_percent_;
00219 }

Member Data Documentation

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

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

Definition at line 368 of file Caching_Strategies_T.h.

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

The level about which the purging will happen automagically.

Definition at line 364 of file Caching_Strategies_T.h.

The documentation for this class was generated from the following files:
Generated on Sun Jan 27 12:55:15 2008 for ACE by doxygen 1.3.6