caches::LFUCachePolicy< Key > Class Template Reference

LFU (Least frequently used) cache policy. More...

#include <lfu_cache_policy.hpp>

Inheritance diagram for caches::LFUCachePolicy< Key >:

Collaboration diagram for caches::LFUCachePolicy< Key >:

Public Types
using	lfu_iterator = typename std::multimap< std::size_t, Key >::iterator

Public Member Functions
void	Insert (const Key &key) override
	Handle element insertion in a cache.
void	Touch (const Key &key) override
	Handle request to the key-element in a cache.
void	Erase (const Key &key) noexcept override
	Handle element deletion from a cache.
const Key &	ReplCandidate () const noexcept override
	Return a key of a replacement candidate.
virtual void	Insert (const Key &key)=0
	Handle element insertion in a cache.
virtual void	Touch (const Key &key)=0
	Handle request to the key-element in a cache.
virtual void	Erase (const Key &key)=0
	Handle element deletion from a cache.
virtual const Key &	ReplCandidate () const =0
	Return a key of a replacement candidate.

Detailed Description

template<typename Key>
class caches::LFUCachePolicy< Key >

LFU (Least frequently used) cache policy.

LFU policy in the case of replacement removes the least frequently used element.

Each access to an element in the cache increments internal counter (frequency) that represents how many times that particular key has been accessed by someone. When a replacement has to occur the LFU policy just takes a look onto keys' frequencies and remove the least used one. E.g. cache of two elements where A has been accessed 10 times and B – only 2. When you want to add a key C the LFU policy returns B as a replacement candidate.

Template Parameters

Key	Type of a key a policy works with

Member Function Documentation

Erase()

template<typename Key >

void caches::LFUCachePolicy< Key >::Erase ( const Key &  key )

inlineoverridevirtualnoexcept

Handle element deletion from a cache.

Parameters

[in]

key

Key that should be used by the policy

Implements caches::ICachePolicy< Key >.

Insert()

template<typename Key >

void caches::LFUCachePolicy< Key >::Insert ( const Key &  key )

inlineoverridevirtual

Handle element insertion in a cache.

Parameters

[in]

key

Key that should be used by the policy

Implements caches::ICachePolicy< Key >.

ReplCandidate()

template<typename Key >

const Key & caches::LFUCachePolicy< Key >::ReplCandidate ( ) const

inlineoverridevirtualnoexcept

Return a key of a replacement candidate.

Returns

Replacement candidate according to selected policy

Implements caches::ICachePolicy< Key >.

Touch()

template<typename Key >

void caches::LFUCachePolicy< Key >::Touch ( const Key &  key )

inlineoverridevirtual

Handle request to the key-element in a cache.

Parameters

key

Implements caches::ICachePolicy< Key >.

---

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

• lfu_cache_policy.hpp