pcpp::LRUList< T > Class Template Reference

#include <LRUList.h>

Public Member Functions
	LRUList (size_t maxSize)
int	put (const T &element, T *deletedValue=nullptr)
const T &	getMRUElement () const
const T &	getLRUElement () const
void	eraseElement (const T &element)
size_t	getMaxSize () const
size_t	getSize () const

Detailed Description

template<typename T>
class pcpp::LRUList< T >

A template class that implements a LRU cache with limited size. Each time the user puts an element it goes to head of the list as the most recently used element (if the element was already in the list it advances to the head of the list). The last element in the list is the one least recently used and will be pulled out of the list if it reaches its max size and a new element comes in. All actions on this LRU list are O(1)

Constructor & Destructor Documentation

LRUList()

template<typename T >

pcpp::LRUList< T >::LRUList ( size_t  maxSize )

inlineexplicit

A c'tor for this class

Parameters

[in]

maxSize

The max size this list can go

Member Function Documentation

eraseElement()

template<typename T >

void pcpp::LRUList< T >::eraseElement ( const T &  element )

inline

Erase an element from the list. If element isn't found in the list nothing happens

Parameters

[in]

element

The element to erase

getLRUElement()

template<typename T >

const T& pcpp::LRUList< T >::getLRUElement ( ) const

inline

Get the least recently used element (the one at the end of the list)

Returns

The least recently used element

getMaxSize()

template<typename T >

size_t pcpp::LRUList< T >::getMaxSize ( ) const

inline

Returns

The max size of this list as determined in the c'tor

getMRUElement()

template<typename T >

const T& pcpp::LRUList< T >::getMRUElement ( ) const

inline

Get the most recently used element (the one at the beginning of the list)

Returns

The most recently used element

getSize()

template<typename T >

size_t pcpp::LRUList< T >::getSize ( ) const

inline

Returns

The number of elements currently in this list

put()

template<typename T >

int pcpp::LRUList< T >::put ( const T &  element, T *  deletedValue = nullptr  )

inline

Puts an element in the list. This element will be inserted (or advanced if it already exists) to the head of the list as the most recently used element. If the list already reached its max size and the element is new this method will remove the least recently used element and return a value in deletedValue. Method complexity is O(log(getSize())). This is a optimized version of the method T* put(const T&).

Parameters

[in]	element	The element to insert or to advance to the head of the list (if already exists)
[out]	deletedValue	The value of deleted element if a pointer is not nullptr. This parameter is optional.

Returns

0 if the list didn't reach its max size, 1 otherwise. In case the list already reached its max size and deletedValue is not nullptr the value of deleted element is copied into the place the deletedValue points to.