ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES > Class Template Reference

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

#include <Caching_Utility_T.h>

List of all members.

Public Types
typedef ACE_Cleanup_Strategy< KEY, VALUE, CONTAINER >	CLEANUP_STRATEGY
Public Member Functions
	ACE_Pair_Caching_Utility (ACE_Cleanup_Strategy< KEY, VALUE, CONTAINER > *cleanup_strategy=0, int delete_cleanup_strategy=0)
	Constructor.
	~ACE_Pair_Caching_Utility (void)
	Destructor.
int	clear_cache (CONTAINER &container, double purge_percent)
Protected Member Functions
void	minimum (CONTAINER &container, KEY *&key_to_remove, VALUE *&value_to_remove)
	Find the entry with minimum caching attributes.
void	operator= (const APUTIL< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES > &)
	APUTIL (const APUTIL< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES > &)
Protected Attributes
CLEANUP_STRATEGY *	cleanup_strategy_
int	delete_cleanup_strategy_
	Whether the cleanup_strategy should be destroyed or not.

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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: 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 47 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< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::CLEANUP_STRATEGY

Definition at line 51 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_BEGIN_VERSIONED_NAMESPACE_DECL 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 21 of file Caching_Utility_T.cpp. References ACE_NEW, and ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::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 35 of file Caching_Utility_T.cpp. References ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::cleanup_strategy_, and ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::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 42 of file Caching_Utility_T.cpp. References ACE_MAX, ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::cleanup_strategy_, and ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::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 const entries_to_remove = ACE_MAX (static_cast<size_t> (1), static_cast<size_t> (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 90 of file Caching_Utility_T.cpp. Referenced by ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::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< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::cleanup_strategy_ [protected]

The cleanup strategy which can be used to destroy the entries of the container. Definition at line 76 of file Caching_Utility_T.h. Referenced by ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::clear_cache(), and ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::~ACE_Pair_Caching_Utility().

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

Whether the cleanup_strategy should be destroyed or not. Definition at line 79 of file Caching_Utility_T.h. Referenced by ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::ACE_Pair_Caching_Utility(), and ACE_Pair_Caching_Utility< KEY, VALUE, CONTAINER, ITERATOR, ATTRIBUTES >::~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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