A concurrent map container which can be stored in persistent memory. This container does not allocate mutex objects internally, but allocates them as static objects. To achieve high concurrency, this container allocates multiple banks, where a bank consists of an actual STL map object and a mutex object. More...

#include </home/runner/work/metall/metall/include/metall/container/concurrent_map.hpp>

Public Types
using	key_type = typename internal_map_type::key_type
	A key type.

using	mapped_type = typename internal_map_type::mapped_type
	A mapped type.

using	value_type = typename internal_map_type::value_type
	A value type (i.e., std::pair<const key_type, mapped_type>).

using	size_type = typename internal_map_type::size_type
	A unsigned integer type (usually std::size_t).

using	allocator_type = _allocator
	An allocator type.

using	const_iterator = metall::utility::container_of_containers_iterator_adaptor< typename banked_map_type::const_iterator, typename internal_map_type::const_iterator >
	A const iterator type.

Public Member Functions
	concurrent_map (const _allocator &allocator=_allocator())

size_type	count (const key_type &key) const
	Returns the number of elements matching specific key.

size_type	size () const
	Returns the number of elements in the container.

bool	insert (value_type &&value)
	Inserts element into the container if the container doesn't already contain an element with an equivalent key.

std::pair< mapped_type &, std::unique_lock< std::mutex > >	scoped_edit (const key_type &key)
	Provides a way to edit an element exclusively. If no element exists with an equivalent key, this container creates a new element with key.

void	edit (const key_type &key, const std::function< void(mapped_type &mapped_value)> &editor)
	Provides a way to edit an element exclusively. If no element exists with an equivalent key, this container creates a new element with key.

const_iterator	cbegin () const
	Returns an iterator to the first element of the map. If the container is empty, the returned iterator will be equal to end().

const_iterator	cend () const
	Returns an iterator to the element following the last element of the map. This element acts as a placeholder; attempting to access it results in undefined behavior.

const_iterator	find (const key_type &key) const
	Finds an element with an equivalent key.

allocator_type	get_allocator () const
	Returns the allocator associated with the container.

Detailed Description

template<typename _key_type, typename _mapped_type, typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>
class metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >

A concurrent map container which can be stored in persistent memory. This container does not allocate mutex objects internally, but allocates them as static objects. To achieve high concurrency, this container allocates multiple banks, where a bank consists of an actual STL map object and a mutex object.

Template Parameters

_key_type	A key type.
_mapped_type	A mapped type.
_compare	A key compare.
_bank_no_hasher	A key hasher.
_allocator	An allocator.
k_num_banks	The number of banks to be allocated.

Examples: concurrent_map.cpp.

Member Typedef Documentation

◆ key_type

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

using metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::key_type = typename internal_map_type::key_type

A key type.

◆ mapped_type

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

using metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::mapped_type = typename internal_map_type::mapped_type

A mapped type.

◆ value_type

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

using metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::value_type = typename internal_map_type::value_type

A value type (i.e., std::pair<const key_type, mapped_type>).

◆ size_type

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

using metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::size_type = typename internal_map_type::size_type

A unsigned integer type (usually std::size_t).

◆ allocator_type

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

using metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::allocator_type = _allocator

An allocator type.

◆ const_iterator

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

using metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::const_iterator = metall::utility::container_of_containers_iterator_adaptor< typename banked_map_type::const_iterator, typename internal_map_type::const_iterator>

A const iterator type.

Constructor & Destructor Documentation

◆ concurrent_map()

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::concurrent_map ( const _allocator & allocator = _allocator() )

inlineexplicit

Member Function Documentation

◆ count()

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

size_type metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::count ( const key_type & key ) const

inline

Returns the number of elements matching specific key.

Parameters

key	A key value of the elements to count.

Returns: The number of elements with key that compares equivalent to key, which is either 1 or 0.

◆ size()

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

size_type metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::size ( ) const

inline

Returns the number of elements in the container.

Returns: The number of elements in the container.

◆ insert()

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

bool metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::insert ( value_type && value )

inline

Inserts element into the container if the container doesn't already contain an element with an equivalent key.

Parameters

value An element value to insert.

Returns: A bool denoting whether the insertion took place.

Examples: concurrent_map.cpp.

◆ scoped_edit()

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

std::pair< mapped_type &, std::unique_lock< std::mutex > > metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::scoped_edit ( const key_type & key )

inline

Provides a way to edit an element exclusively. If no element exists with an equivalent key, this container creates a new element with key.

Parameters

key	A key of the element to edit.

Returns: A pair of a reference to the element and a mutex ownership wrapper.

◆ edit()

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

void metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::edit	(	const key_type &	key,
		const std::function< void(mapped_type &mapped_value)> &	editor
	)

inline

Provides a way to edit an element exclusively. If no element exists with an equivalent key, this container creates a new element with key.

Parameters

key	A key of the element to edit.
editor	A function object which edits an element.

◆ cbegin()

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

const_iterator metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::cbegin ( ) const

inline

Returns an iterator to the first element of the map. If the container is empty, the returned iterator will be equal to end().

Returns: A const iterator to the first element.

◆ cend()

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

const_iterator metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::cend ( ) const

inline

Returns an iterator to the element following the last element of the map. This element acts as a placeholder; attempting to access it results in undefined behavior.

Returns: A const iterator to the element following the last element.

◆ find()

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

const_iterator metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::find ( const key_type & key ) const

inline

Finds an element with an equivalent key.

Parameters

key	A key value of the element to search for

Returns: An iterator to an element with an equivalent key. If no such element is found, the returned iterator will be equal to end().

◆ get_allocator()

template<typename _key_type , typename _mapped_type , typename _compare = std::less<_key_type>, typename _bank_no_hasher = std::hash<_key_type>, typename _allocator = std::allocator<std::pair<const _key_type, _mapped_type>>, int k_num_banks = 1024>

allocator_type metall::container::concurrent_map< _key_type, _mapped_type, _compare, _bank_no_hasher, _allocator, k_num_banks >::get_allocator ( ) const

inline

Returns the allocator associated with the container.

Returns: An object of the associated allocator.

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

/home/runner/work/metall/metall/include/metall/container/concurrent_map.hpp

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ key_type

◆ mapped_type

◆ value_type

◆ size_type

◆ allocator_type

◆ const_iterator

Constructor & Destructor Documentation

◆ concurrent_map()

Member Function Documentation

◆ count()

◆ size()

◆ insert()

◆ scoped_edit()

◆ edit()

◆ cbegin()

◆ cend()

◆ find()

◆ get_allocator()