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ACE_Pair_Caching_Utility Class Template Reference

Defines a helper class for the Caching Strategies. More...

#include <Caching_Utility_T.h>

Collaboration diagram for ACE_Pair_Caching_Utility:

[legend]List of all members.

Public Types
typedef ACE_Cleanup_Strategy< KEY, VALUE, CONTAINER >	CLEANUP_STRATEGY
Public Methods
	ACE_Pair_Caching_Utility (ACE_Cleanup_Strategy< KEY, VALUE, CONTAINER > *cleanup_strategy=0, int delete_cleanup_strategy=0)
	Constructor. More...
	~ACE_Pair_Caching_Utility (void)
	Destructor. More...
int	clear_cache (CONTAINER &container, double purge_percent)
Protected Methods
void	minimum (CONTAINER &container, KEY *&key_to_remove, VALUE *&value_to_remove)
	Find the entry with minimum caching attributes. More...
void	operator= (const APUTIL< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES > &)
	APUTIL (const APUTIL< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES > &)
Protected Attributes
CLEANUP_STRATEGY *	cleanup_strategy_
	The cleanup strategy which can be used to destroy the entries of the container. More...
int	delete_cleanup_strategy_
	Whether the cleanup_strategy should be destroyed or not. More...

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Detailed Description

template<class KEY, class VALUE, class CONTAINER, class ITERATOR, class ATTRIBUTES>
class ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >

Defines a helper class for the Caching Strategies.

This class defines the methods commonly used by the different caching strategies. For instance: <clear_cache> method which decides and purges the entry from the container. Note: This class helps in the caching_strategies using a container containing entries of <KEY, ACE_Pair<VALUE, attributes>> kind. The attributes helps in deciding the entries to be purged. The Cleanup_Strategy is the callback class to which the entries to be cleaned up will be delegated.

Definition at line 45 of file Caching_Utility_T.h.

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Member Typedef Documentation

template<class KEY, class VALUE, class CONTAINER, class ITERATOR, class ATTRIBUTES> typedef ACE_Cleanup_Strategy<KEY, VALUE, CONTAINER> ACE_Pair_Caching_Utility::CLEANUP_STRATEGY

Definition at line 49 of file Caching_Utility_T.h.

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Constructor & Destructor Documentation

template<class KEY, class VALUE, class CONTAINER, class ITERATOR, class ATTRIBUTES> ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::ACE_Pair_Caching_Utility (  ACE_Cleanup_Strategy< KEY, VALUE, CONTAINER > *    cleanup_strategy = 0, int    delete_cleanup_strategy = 0 )

Constructor. Definition at line 22 of file Caching_Utility_T.cpp. References ACE_NEW, and delete_cleanup_strategy_. : cleanup_strategy_ (cleanup_strategy), delete_cleanup_strategy_ (delete_cleanup_strategy) { if (cleanup_strategy == 0) { ACE_NEW (this->cleanup_strategy_, CLEANUP_STRATEGY); this->delete_cleanup_strategy_ = 1; } }

template<class KEY, class VALUE, class CONTAINER, class ITERATOR, class ATTRIBUTES> ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::~ACE_Pair_Caching_Utility (  void    )

Destructor. Definition at line 36 of file Caching_Utility_T.cpp. References cleanup_strategy_, and delete_cleanup_strategy_. { if (this->delete_cleanup_strategy_) delete this->cleanup_strategy_; }

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Member Function Documentation

template<class KEY, class VALUE, class CONTAINER, class ITERATOR, class ATTRIBUTES> ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::APUTIL (  const APUTIL< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES > &    )  [protected]

template<class KEY, class VALUE, class CONTAINER, class ITERATOR, class ATTRIBUTES> int ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::clear_cache (  CONTAINER &    container, double    purge_percent )

Purge entries from the <container>. The Cleanup_Strategy will do the actual job of cleanup once the entries to be cleaned up are decided. Definition at line 43 of file Caching_Utility_T.cpp. References ACE_MAX, ACE_Cleanup_Strategy::cleanup, cleanup_strategy_, and minimum. { // Check that the purge_percent is non-zero. if (purge_percent == 0) return 0; // Get the number of entries in the container. size_t current_map_size = container.current_size (); // Also whether the number of entries in the cache! // Oops! then there is no way out but exiting. So return an error. if (current_map_size == 0) return 0; // Calculate the no of entries to remove from the cache depending // upon the <purge_percent>. size_t entries_to_remove = ACE_MAX (ACE_static_cast (size_t, 1), ACE_static_cast (size_t, ACE_static_cast(double, purge_percent) / 100 * current_map_size)); KEY *key_to_remove = 0; VALUE *value_to_remove = 0; for (size_t i = 0; i < entries_to_remove ; ++i) { this->minimum (container, key_to_remove, value_to_remove); // Simply verifying that the key is non-zero. // This is important for strategies where the minimum // entry cant be found due to constraints on the type of entry // to remove. if (key_to_remove == 0) return 0; if (this->cleanup_strategy_->cleanup (container, key_to_remove, value_to_remove) == -1) return -1; } return 0; }

template<class KEY, class VALUE, class CONTAINER, class ITERATOR, class ATTRIBUTES> void ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::minimum (  CONTAINER &    container, KEY *&    key_to_remove, VALUE *&    value_to_remove )  [protected]

Find the entry with minimum caching attributes. Definition at line 92 of file Caching_Utility_T.cpp. Referenced by clear_cache. { // Starting values. ITERATOR iter = container.begin (); ITERATOR end = container.end (); ATTRIBUTES min = (*iter).int_id_.second (); key_to_remove = &(*iter).ext_id_; value_to_remove = &(*iter).int_id_; // The iterator moves thru the container searching for the entry // with the lowest ATTRIBUTES. for (++iter; iter != end; ++iter) { if (min > (*iter).int_id_.second ()) { // Ah! an item with lower ATTTRIBUTES... min = (*iter).int_id_.second (); key_to_remove = &(*iter).ext_id_; value_to_remove = &(*iter).int_id_; } } }

template<class KEY, class VALUE, class CONTAINER, class ITERATOR, class ATTRIBUTES> void ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::operator= (  const APUTIL< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES > &    )  [protected]

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Member Data Documentation

template<class KEY, class VALUE, class CONTAINER, class ITERATOR, class ATTRIBUTES> CLEANUP_STRATEGY* ACE_Pair_Caching_Utility::cleanup_strategy_ [protected]

The cleanup strategy which can be used to destroy the entries of the container. Definition at line 74 of file Caching_Utility_T.h. Referenced by clear_cache, and ~ACE_Pair_Caching_Utility.

template<class KEY, class VALUE, class CONTAINER, class ITERATOR, class ATTRIBUTES> int ACE_Pair_Caching_Utility::delete_cleanup_strategy_ [protected]

Whether the cleanup_strategy should be destroyed or not. Definition at line 77 of file Caching_Utility_T.h. Referenced by ACE_Pair_Caching_Utility, and ~ACE_Pair_Caching_Utility.

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

• Caching_Utility_T.h
• Caching_Utility_T.cpp

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