cache::LruMap< T, U, Hash, Equal > Class Template Reference

#include <userver/cache/lru_map.hpp>

Detailed Description

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>
class cache::LruMap< T, U, Hash, Equal >

LRU key value storage (LRU cache), thread safety matches Standard Library thread safety

Definition at line 18 of file lru_map.hpp.

Public Member Functions
	LruMap (size_t max_size, const Hash &hash=Hash(), const Equal &equal=Equal())
	LruMap (LruMap &&lru) noexcept=default
	LruMap (const LruMap &lru)=delete
LruMap &	operator= (LruMap &&lru) noexcept=default
LruMap &	operator= (const LruMap &lru)=delete
bool	Put (const T &key, U value)
template<typename... Args>
U *	Emplace (const T &key, Args &&... args)
void	Erase (const T &key)
	Removes key from LRU.
U *	Get (const T &key)
U	GetOr (const T &key, const U &default_value)
U *	GetLeastUsed ()
void	SetMaxSize (size_t new_max_size)
	Sets the max size of the LRU, truncates values if new_max_size < GetSize()
void	Clear ()
	Removes all the elements.
template<typename Function>
void	VisitAll (Function &&func) const
	Call Function(const T&, const U&) for all items.
template<typename Function>
void	VisitAll (Function &&func)
	Call Function(const T&, U&) for all items.
size_t	GetSize () const
std::size_t	GetCapacity () const

Constructor & Destructor Documentation

LruMap()

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

cache::LruMap< T, U, Hash, Equal >::LruMap ( size_t max_size, const Hash & hash = Hash(), const Equal & equal = Equal() )

inlineexplicit

Definition at line 20 of file lru_map.hpp.

Member Function Documentation

Clear()

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

void cache::LruMap< T, U, Hash, Equal >::Clear ( )

inline

Removes all the elements.

Definition at line 65 of file lru_map.hpp.

Emplace()

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

template<typename... Args>

U * cache::LruMap< T, U, Hash, Equal >::Emplace ( const T & key, Args &&... args )

inline

Returns pointer to value if the key is in LRU and updates its usage; constructs and adds a new key/value otherwise.

Warning

Returned pointer may be freed on the next map access!

Definition at line 36 of file lru_map.hpp.

Erase()

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

void cache::LruMap< T, U, Hash, Equal >::Erase ( const T & key )

inline

Removes key from LRU.

Definition at line 41 of file lru_map.hpp.

Get()

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

U * cache::LruMap< T, U, Hash, Equal >::Get ( const T & key )

inline

Returns pointer to value if the key is in LRU and updates its usage; returns nullptr otherwise.

Warning

Returned pointer may be freed on the next map access!

Definition at line 46 of file lru_map.hpp.

GetCapacity()

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

std::size_t cache::LruMap< T, U, Hash, Equal >::GetCapacity ( ) const

inline

Definition at line 81 of file lru_map.hpp.

GetLeastUsed()

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

U * cache::LruMap< T, U, Hash, Equal >::GetLeastUsed ( )

inline

Returns pointer to the least recently used value; returns nullptr if LRU is empty.

Warning

Returned pointer may be freed on the next map access!

Definition at line 59 of file lru_map.hpp.

GetOr()

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

U cache::LruMap< T, U, Hash, Equal >::GetOr ( const T & key, const U & default_value )

inline

Returns value by key and updates its usage; returns default_value otherwise without modifying the cache.

Definition at line 50 of file lru_map.hpp.

GetSize()

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

size_t cache::LruMap< T, U, Hash, Equal >::GetSize ( ) const

inline

Definition at line 79 of file lru_map.hpp.

Put()

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

bool cache::LruMap< T, U, Hash, Equal >::Put ( const T & key, U value )

inline

Adds or rewrites key/value, updates its usage

Returns

true if key is a new one

Definition at line 30 of file lru_map.hpp.

SetMaxSize()

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

void cache::LruMap< T, U, Hash, Equal >::SetMaxSize ( size_t new_max_size )

inline

Sets the max size of the LRU, truncates values if new_max_size < GetSize()

Definition at line 62 of file lru_map.hpp.

VisitAll() [1/2]

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

template<typename Function>

void cache::LruMap< T, U, Hash, Equal >::VisitAll ( Function && func )

inline

Call Function(const T&, U&) for all items.

Definition at line 75 of file lru_map.hpp.

VisitAll() [2/2]

template<typename T, typename U, typename Hash = std::hash<T>, typename Equal = std::equal_to<T>>

template<typename Function>

void cache::LruMap< T, U, Hash, Equal >::VisitAll ( Function && func ) const

inline

Call Function(const T&, const U&) for all items.

Definition at line 69 of file lru_map.hpp.

---

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

• userver/cache/lru_map.hpp