Unordered map from Key to T. More...

#include <concurrent_hash_map.h>

Inheritance diagram for tbb::interface5::concurrent_hash_map< Key, T, HashCompare, A >:

Classes
class	accessor
	Allows write access to elements and combines data access, locking, and garbage collection. More...

class	bucket_accessor
	bucket accessor is to find, rehash, acquire a lock, and access a bucket More...

class	const_accessor
	Combines data access, locking, and garbage collection. More...

struct	node

Public Types
typedef Key	key_type

typedef T	mapped_type

typedef std::pair< const Key, T >	value_type

typedef hash_map_base::size_type	size_type

typedef ptrdiff_t	difference_type

typedef value_type *	pointer

typedef const value_type *	const_pointer

typedef value_type &	reference

typedef const value_type &	const_reference

typedef internal::hash_map_iterator < concurrent_hash_map, value_type >	iterator

typedef internal::hash_map_iterator < concurrent_hash_map, const value_type >	const_iterator

typedef internal::hash_map_range < iterator >	range_type

typedef internal::hash_map_range < const_iterator >	const_range_type

typedef Allocator	allocator_type

Public Member Functions
	concurrent_hash_map (const allocator_type &a=allocator_type())
	Construct empty table.

	concurrent_hash_map (size_type n, const allocator_type &a=allocator_type())
	Construct empty table with n preallocated buckets. This number serves also as initial concurrency level.

	concurrent_hash_map (const concurrent_hash_map &table, const allocator_type &a=allocator_type())
	Copy constructor.

template<typename I >
	concurrent_hash_map (I first, I last, const allocator_type &a=allocator_type())
	Construction with copying iteration range and given allocator instance.

	concurrent_hash_map (const std::initializer_list< value_type > &il, const allocator_type &a=allocator_type())
	Construct empty table with n preallocated buckets. This number serves also as initial concurrency level.

concurrent_hash_map &	operator= (const concurrent_hash_map &table)
	Assignment.

concurrent_hash_map &	operator= (const std::initializer_list< value_type > &il)
	Assignment.

void	rehash (size_type n=0)
	Rehashes and optionally resizes the whole table. More...

void	clear ()
	Clear table.

	~concurrent_hash_map ()
	Clear table and destroy it.

range_type	range (size_type grainsize=1)

const_range_type	range (size_type grainsize=1) const

iterator	begin ()

iterator	end ()

const_iterator	begin () const

const_iterator	end () const

std::pair< iterator, iterator >	equal_range (const Key &key)

std::pair< const_iterator, const_iterator >	equal_range (const Key &key) const

size_type	size () const
	Number of items in table.

bool	empty () const
	True if size()==0.

size_type	max_size () const
	Upper bound on size.

size_type	bucket_count () const
	Returns the current number of buckets.

allocator_type	get_allocator () const
	return allocator object

void	swap (concurrent_hash_map &table)
	swap two instances. Iterators are invalidated

size_type	count (const Key &key) const
	Return count of items (0 or 1)

bool	find (const_accessor &result, const Key &key) const
	Find item and acquire a read lock on the item. More...

bool	find (accessor &result, const Key &key)
	Find item and acquire a write lock on the item. More...

bool	insert (const_accessor &result, const Key &key)
	Insert item (if not already present) and acquire a read lock on the item. More...

bool	insert (accessor &result, const Key &key)
	Insert item (if not already present) and acquire a write lock on the item. More...

bool	insert (const_accessor &result, const value_type &value)
	Insert item by copying if there is no such key present already and acquire a read lock on the item. More...

bool	insert (accessor &result, const value_type &value)
	Insert item by copying if there is no such key present already and acquire a write lock on the item. More...

bool	insert (const value_type &value)
	Insert item by copying if there is no such key present already. More...

template<typename I >
void	insert (I first, I last)
	Insert range [first, last)

bool	erase (const Key &key)
	Erase item. More...

bool	erase (const_accessor &item_accessor)
	Erase item by const_accessor. More...

bool	erase (accessor &item_accessor)
	Erase item by accessor. More...

Protected Types
typedef Allocator::template rebind< node >::other	node_allocator_type

Protected Member Functions
void	delete_node (node_base *n)

node *	search_bucket (const key_type &key, bucket *b) const

void	rehash_bucket (bucket *b_new, const hashcode_t h)

bool	lookup (bool op_insert, const Key &key, const T t, const_accessor result, bool write)
	Insert or find item and optionally acquire a lock on the item.

bool	exclude (const_accessor &item_accessor)
	delete item by accessor

template<typename I >
std::pair< I, I >	internal_equal_range (const Key &key, I end) const
	Returns an iterator for an item defined by the key, or for the next item after it (if upper==true)

void	internal_copy (const concurrent_hash_map &source)
	Copy "source" to this, where this must start out empty.

template<typename I >
void	internal_copy (I first, I last)

const_pointer	internal_fast_find (const Key &key) const
	Fast find when no concurrent erasure is used. For internal use inside TBB only! More...

Protected Attributes
node_allocator_type	my_allocator

HashCompare	my_hash_compare

Friends
template<typename Container , typename Value >
class	internal::hash_map_iterator

template<typename I >
class	internal::hash_map_range

class	const_accessor

Detailed Description

template<typename Key, typename T, typename HashCompare = tbb_hash_compare<Key>, typename A = tbb_allocator<std::pair<Key, T> >>
class tbb::interface5::concurrent_hash_map< Key, T, HashCompare, A >

Unordered map from Key to T.

concurrent_hash_map is associative container with concurrent access.

Compatibility: The class meets all Container Requirements from C++ Standard (See ISO/IEC 14882:2003(E), clause 23.1).

Exception Safety

Hash function is not permitted to throw an exception. User-defined types Key and T are forbidden from throwing an exception in destructors.
If exception happens during insert() operations, it has no effect (unless exception raised by HashCompare::hash() function during grow_segment).
If exception happens during operator=() operation, the container can have a part of source items, and methods size() and empty() can return wrong results.

Changes since TBB 2.1

Replaced internal algorithm and data structure. Patent is pending.
Added buckets number argument for constructor

Changes since TBB 2.0

Fixed exception-safety
Added template argument for allocator
Added allocator argument in constructors
Added constructor from a range of iterators
Added several new overloaded insert() methods
Added get_allocator()
Added swap()
Added count()
Added overloaded erase(accessor &) and erase(const_accessor&)
Added equal_range() [const]
Added [const_]pointer, [const_]reference, and allocator_type types
Added global functions: operator==(), operator!=(), and swap()

Member Function Documentation

template<typename Key , typename T , typename HashCompare , typename A >

bool tbb::interface5::concurrent_hash_map< Key, T, HashCompare, A >::erase ( const Key & key)

Erase item.

Return true if item was erased by particularly this call.

References tbb::interface5::concurrent_hash_map< Key, T, HashCompare, A >::bucket_accessor::is_writer().