ACE: ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY > Class Template Reference

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

#include <Caching_Strategies_T.h>

List of all members.

Public Types
typedef ATTRIBUTES	CACHING_ATTRIBUTES
Public Member Functions
	ACE_LRU_Caching_Strategy (void)
ATTRIBUTES	attributes (void)
	Accessor method for the timer 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)
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
ATTRIBUTES	timer_
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_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >

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

This is a strategy which makes use of a virtual timer which is updated whenever an item is inserted or looked up in the container. When the need of purging entries arises, the items with the lowest timer values are removed. 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 199 of file Caching_Strategies_T.h.

Member Typedef Documentation

template<class ATTRIBUTES , class CACHING_UTILITY >

typedef ATTRIBUTES ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::CACHING_ATTRIBUTES

Definition at line 204 of file Caching_Strategies_T.h.

Constructor & Destructor Documentation

template<class ATTRIBUTES , class CACHING_UTILITY >

ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::ACE_LRU_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 27 of file Caching_Strategies_T.cpp.

  : timer_ (0),
    purge_percent_ (10)
{
}

Member Function Documentation

template<class ATTRIBUTES , class CACHING_UTILITY >

ATTRIBUTES ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::attributes ( void ) [inline]

Accessor method for the timer attributes.

Definition at line 120 of file Caching_Strategies_T.inl.

{
  return this->timer_;
}

template<class ATTRIBUTES , class CACHING_UTILITY >

CACHING_UTILITY & ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::caching_utility ( void ) [inline]

Purge the cache.

Definition at line 190 of file Caching_Strategies_T.inl.

{
  return this->caching_utility_;
}

template<class ATTRIBUTES , class CACHING_UTILITY >

void ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::dump ( void ) const [inline]

Dumps the state of the object.

Definition at line 196 of file Caching_Strategies_T.inl.

{
#if defined (ACE_HAS_DUMP)
  ACE_TRACE ("ACE_LRU_Caching_Strategy::dump");

  ACE_DEBUG ((LM_DEBUG, ACE_BEGIN_DUMP, this));
  ACE_DEBUG ((LM_DEBUG,  ACE_TEXT ("timer_ = %d "), this->timer_));
  ACE_DEBUG ((LM_DEBUG, ACE_END_DUMP));
#endif /* ACE_HAS_DUMP */
}

template<class ATTRIBUTES , class CACHING_UTILITY >

int ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::notify_bind	(	int	result,
		const ATTRIBUTES &	attr
	)			`[inline]`

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

Definition at line 138 of file Caching_Strategies_T.inl.

{
  if (result == 0)
    ++this->timer_;

  return result;
}

template<class ATTRIBUTES , class CACHING_UTILITY >

int ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::notify_find	(	int	result,
		ATTRIBUTES &	attr
	)			`[inline]`

This method acts as a notification about the CONTAINERs find method call

Definition at line 149 of file Caching_Strategies_T.inl.

{
  if (result == 0)
    {
      attr = this->timer_;
      ++this->timer_;
    }

  return result;
}

template<class ATTRIBUTES , class CACHING_UTILITY >

int ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::notify_rebind	(	int	result,
		const ATTRIBUTES &	attr
	)			`[inline]`

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

Definition at line 179 of file Caching_Strategies_T.inl.

{
  if (result == 0)
    ++this->timer_;

  return result;
}

template<class ATTRIBUTES , class CACHING_UTILITY >

int ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::notify_trybind	(	int	result,
		ATTRIBUTES &	attr
	)			`[inline]`

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

Definition at line 171 of file Caching_Strategies_T.inl.

{
  return result;
}

template<class ATTRIBUTES , class CACHING_UTILITY >

int ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::notify_unbind	(	int	result,
		const ATTRIBUTES &	attr
	)			`[inline]`

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

Definition at line 163 of file Caching_Strategies_T.inl.

{
  return result;
}

template<class ATTRIBUTES , class CACHING_UTILITY >

double ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::purge_percent ( void ) [inline]

Get the percentage of entries to purge.

Definition at line 126 of file Caching_Strategies_T.inl.

{
  return this->purge_percent_;
}

template<class ATTRIBUTES , class CACHING_UTILITY >

void ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::purge_percent ( double percentage ) [inline]

Set the percentage of entries to purge.

Definition at line 132 of file Caching_Strategies_T.inl.

{
  this->purge_percent_ = percentage;
}

Member Data Documentation

template<class ATTRIBUTES , class CACHING_UTILITY >

CACHING_UTILITY ACE_LRU_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 273 of file Caching_Strategies_T.h.

template<class ATTRIBUTES , class CACHING_UTILITY >

double ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::purge_percent_ [private]

The level about which the purging will happen automagically.

Definition at line 269 of file Caching_Strategies_T.h.

template<class ATTRIBUTES , class CACHING_UTILITY >

ATTRIBUTES ACE_LRU_Caching_Strategy< ATTRIBUTES, CACHING_UTILITY >::timer_ [private]

This element is the one which is the deciding factor for purging of an ITEM.

Definition at line 266 of file Caching_Strategies_T.h.

The documentation for this class was generated from the following files:

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