2 This file is a part of libcds - Concurrent Data Structures library
4 (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2016
6 Source code repo: http://github.com/khizmax/libcds/
7 Download: http://sourceforge.net/projects/libcds/files/
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31 #ifndef CDSLIB_CONTAINER_STRIPED_MAP_H
32 #define CDSLIB_CONTAINER_STRIPED_MAP_H
34 #include <type_traits>
35 #include <cds/container/striped_set.h>
36 #include <cds/container/striped_set/adapter.h>
37 #include <cds/details/binary_functor_wrapper.h>
39 namespace cds { namespace container {
43 template <class Container, typename... Options>
44 class make_striped_map
46 typedef StripedSet< Container, Options...> billet;
47 typedef typename billet::options billet_options;
48 typedef typename billet_options::hash billet_hash;
50 typedef typename Container::value_type pair_type;
51 typedef typename pair_type::first_type key_type;
53 struct options: public billet_options {
54 struct hash: public billet_hash {
55 size_t operator()( pair_type const& v ) const
57 return billet_hash::operator()( v.first );
61 size_t operator()( Q const& v ) const
63 return billet_hash::operator()( v );
69 typedef StripedSet< Container, cds::opt::type_traits< options > > type ; ///< metafunction result
75 /** @ingroup cds_nonintrusive_map
78 - [2008] Maurice Herlihy, Nir Shavit "The Art of Multiprocessor Programming"
80 Lock striping is very simple technique.
81 The map consists of the bucket table and the array of locks.
82 Initially, the capacity of lock array and bucket table is the same.
83 When the map is resized, bucket table capacity will be doubled but lock array will not.
84 The lock \p i protects each bucket \p j, where <tt> j = i mod L </tt>,
85 where \p L - the size of lock array.
88 - \p Container - the container class that is used as bucket entry. The \p Container class should support
89 an uniform interface described below.
90 - \p Options - options
92 The \p %StripedMap class does not exactly specify the type of container that should be used as a \p Container bucket.
93 Instead, the class supports different container type for the bucket, for exampe, \p std::list, \p std::map and others.
95 Remember that \p %StripedMap class algorithm ensures sequential blocking access to its bucket through the mutex type you specify
96 among \p Options template arguments.
99 - \p cds::opt::mutex_policy - concurrent access policy.
100 Available policies: \p striped_set::striping, \p striped_set::refinable.
101 Default is \p %striped_set::striping.
102 - \p cds::opt::hash - hash functor. Default option value see <tt>opt::v::hash_selector<opt::none> </tt>
103 which selects default hash functor for your compiler.
104 - \p cds::opt::compare - key comparison functor. No default functor is provided.
105 If the option is not specified, the \p %opt::less is used.
106 - \p cds::opt::less - specifies binary predicate used for key comparison. Default is \p std::less<T>.
107 - \p cds::opt::item_counter - item counter type. Default is \p atomicity::item_counter since some operation on the counter is performed
108 without locks. Note that item counting is an essential part of the map algorithm, so dummy counter
109 like as \p atomicity::empty_item_counter is not suitable.
110 - \p cds::opt::allocator - the allocator type using for memory allocation of bucket table and lock array. Default is \ref CDS_DEFAULT_ALLOCATOR.
111 - \p cds::opt::resizing_policy - the resizing policy that is a functor that decides when to resize the hash map.
112 Default option value depends on bucket container type:
113 for sequential containers like \p std::list, \p std::vector the resizing policy is <tt>striped_set::load_factor_resizing<4> </tt>;
114 for other type of containers like \p std::map, \p std::unordered_map the resizing policy is \p striped_set::no_resizing.
115 See \ref cds_striped_resizing_policy "available resizing policy".
116 Note that the choose of resizing policy depends of \p Container type:
117 for sequential containers like \p std::list, \p std::vector and so on, right choosing of the policy can
118 significantly improve performance.
119 For other, non-sequential types of \p Container (like a \p std::map)
120 the resizing policy is not so important.
121 - \p cds::opt::copy_policy - the copy policy which is used to copy items from the old map to the new one when resizing.
122 The policy can be optionally used in adapted bucket container for performance reasons of resizing.
123 The detail of copy algorithm depends on type of bucket container and explains below.
125 \p %opt::compare or \p %opt::less options are used only in some \p Container class for searching an item.
126 \p %opt::compare option has the highest priority: if \p %opt::compare is specified, \p %opt::less is not used.
128 You can pass other option that would be passed to <tt>adapt</tt> metafunction, see below.
130 <b>Internal details</b>
132 The \p %StripedMap class cannot utilize the \p Container container specified directly, but only its adapted variant which
133 supports an unified interface. Internally, the adaptation is made via \p striped_set::adapt metafunction that wraps bucket container
134 and provides the unified bucket interface suitable for \p %StripedMap. Such adaptation is completely transparent for you -
135 you don't need to call \p adapt metafunction directly, \p %StripedMap class's internal machinery itself invokes appropriate
136 \p adapt metafunction to adjust your \p Container container class to \p %StripedMap bucket's internal interface.
137 All you need is to include a right header before <tt>striped_hash_map.h</tt>.
139 By default, <tt>striped_set::adapt<AnyContainer, Options...> </tt> metafunction does not make any wrapping to \p AnyContainer,
140 so, the result <tt>striped_set::adapt<AnyContainer, Options...>::type </tt> is the same as \p AnyContainer.
141 However, there are a lot of specializations of \p adapt for well-known containers, see table below.
142 Any of this specialization wraps corresponding container making it suitable for the map's bucket.
143 Remember, you should include the proper header file for \p adapt <b>before</b> <tt>striped_map.h</tt>.
147 <th>.h-file for \p adapt</th>
152 <td> \p std::list</td>
153 <td><tt><cds/container/striped_map/std_list.h></tt></td>
155 #include <cds/container/striped_map/std_list.h>
156 #include <cds/container/striped_hash_map.h>
157 typedef cds::container::StripedMap<
158 std::list< std::pair< const Key, V > >,
159 cds::opt::less< std::less<Key> >
164 The type of values stored in the \p std::list must be <tt> std::pair< const Key, V > </tt>, where \p Key - key type, and \p V - value type
165 The list is ordered by key \p Key.
166 Template argument pack \p Options <b>must</b> contain \p cds::opt::less or \p cds::opt::compare for type \p Key stored in the list.
170 <td> \p std::map</td>
171 <td><tt><cds/container/striped_map/std_map.h></tt></td>
173 #include <cds/container/striped_map/std_map.h>
174 #include <cds/container/striped_hash_map.h>
175 typedef cds::container::StripedMap<
176 std::map< Key, T, std::less<Key> >
184 <td> \p std::unordered_map</td>
185 <td><tt><cds/container/striped_map/std_hash_map.h></tt></td>
187 #include <cds/container/striped_map/std_hash_map.h>
188 #include <cds/container/striped_hash_map.h>
189 typedef cds::container::StripedMap<
199 You should provide two different hash function \p h1 and \p h2 - one for std::unordered_map and other for \p %StripedMap.
200 For the best result, \p h1 and \p h2 must be orthogonal i.e. <tt> h1(X) != h2(X) </tt> for any value \p X of type \p Key.
204 <td> \p boost::container::slist</td>
205 <td><tt><cds/container/striped_map/boost_slist.h></tt></td>
207 #include <cds/container/hash_smap/boost_slist.h>
208 #include <cds/container/striped_hash_map.h>
209 typedef cds::container::StripedMap<
210 boost::container::slist< std::pair< const Key, T > >
215 The type of values stored in the \p boost::container::slist must be <tt> std::pair< const Key, T > </tt>,
216 where \p Key - key type, and \p T - value type. The list is ordered.
217 \p Options <b>must</b> contain \p cds::opt::less or \p cds::opt::compare.
221 <td> \p boost::container::list</td>
222 <td><tt><cds/container/striped_map/boost_list.h></tt></td>
224 #include <cds/container/striped_map/boost_list.h>
225 #include <cds/container/striped_hash_map.h>
226 typedef cds::container::StripedMap<
227 boost::container::list< std::pair< const Key, T > >
232 The type of values stored in the \p boost::container::list must be <tt> std::pair< const Key, T > </tt>,
233 where \p Key - key type, and \p T - value type. The list is ordered.
234 \p Options <b>must</b> contain \p cds::opt::less or \p cds::opt::compare.
238 <td> \p boost::container::map</td>
239 <td><tt><cds/container/striped_map/boost_map.h></tt></td>
241 #include <cds/container/striped_map/boost_map.h>
242 #include <cds/container/striped_hash_map.h>
243 typedef cds::container::StripedMap<
244 boost::container::map< Key, T, std::less<Key> >
252 <td> \p boost::container::flat_map</td>
253 <td><tt><cds/container/striped_map/boost_flat_map.h></tt></td>
255 #include <cds/container/striped_map/boost_flat_map.h>
256 #include <cds/container/striped_hash_map.h>
257 typedef cds::container::StripedMap<
258 boost::container::flat_map< Key, T,
259 std::less< std::less<Key> >
268 <td> \p boost::unordered_map</td>
269 <td><tt><cds/container/striped_map/boost_unordered_map.h></tt></td>
271 #include <cds/container/striped_map/boost_unordered_map.h>
272 #include <cds/container/refinable_hash_map.h>
273 typedef cds::container::StripedMap<
274 boost::unordered_map< Key, T, boost::hash<Key>, std::equal_to<Key> >
284 You can use another container type as map's bucket.
285 Suppose, you have a container class \p MyBestContainer and you want to integrate it with \p %StripedMap as bucket type.
286 There are two possibility:
287 - either your \p MyBestContainer class has native support of bucket's interface;
288 in this case, you can use default <tt>striped_set::adapt</tt> metafunction;
289 - or your \p MyBestContainer class does not support bucket's interface; it means you should develop a specialization
290 <tt>cds::container::striped_set::adapt<MyBestContainer> </tt> metafunction providing necessary interface.
292 The <tt>striped_set::adapt< Container, Options... ></tt> metafunction has two template argument:
293 - \p Container is the class that should be used as the bucket, for example, <tt>std::list< std::pair< Key, T > ></tt>.
294 - \p Options pack is the options from \p %StripedMap declaration. The \p adapt metafunction can use
295 any option from \p Options for its internal use. For example, a \p compare option can be passed to \p adapt
296 metafunction via \p Options argument of \p %StripedMap declaration.
298 See \p striped_set::adapt metafunction for the description of interface that the bucket container must provide
299 to be \p %StripedMap compatible.
302 There are three predefined copy policy:
303 - \p cds::container::striped_set::copy_item - copy item from old bucket to new one when resizing using copy ctor. It is default policy for
304 any compiler that do not support move semantics
305 - \p cds::container::striped_set::move_item - move item from old bucket to new one when resizing using move semantics. It is default policy for
306 any compiler that support move semantics. If compiler does not support move semantics, the move policy is the same as \p copy_item
307 - \p cds::container::striped_set::swap_item - copy item from old bucket to new one when resizing using \p std::swap. Not all containers support
308 this copy policy, see details in table below.
310 You can define your own copy policy specifically for your case.
311 Note, right copy policy can significantly improve the performance of resizing.
326 std::list< std::pair<const Key, T> >& list,
327 std::list<std::pair<const Key, T> >::iterator itInsert,
328 std::list<std::pair<const Key, T> >::iterator itWhat )
330 list.insert( itInsert, *itWhat );
335 // The type T stored in the list must be swappable
338 std::list< std::pair<const Key, T> >& list,
339 std::list<std::pair<const Key, T> >::iterator itInsert,
340 std::list<std::pair<const Key, T> >::iterator itWhat )
342 std::pair<Key, T> newVal( itWhat->first, T() );
343 std::swap( list.insert( itInsert, newVal )->second, itWhat->second );
350 std::list< std::pair<const Key, T> >& list,
351 std::list<std::pair<const Key, T> >::iterator itInsert,
352 std::list<std::pair<const Key, T> >::iterator itWhat )
354 list.insert( itInsert, std::move( *itWhat ) );
362 - \p std::unordered_map
363 - \p boost::container::map
364 - \p boost::container::flat_map
365 - \p boost::unordered_map
369 void operator()( std::map< Key, T>& map, std::map<Key, T>::iterator itWhat )
371 map.insert( *itWhat );
377 void operator()( std::map< Key, T>& map, std::map<Key, T>::iterator itWhat )
381 std::map::value_type( itWhat->first, T() ) ).first->second
386 \p T type must be swappable.
390 void operator()( std::map< Key, T>& map, std::map<Key, T>::iterator itWhat )
392 map.insert( std::move( *itWhat ));
397 <td> \p boost::container::slist</td>
401 bc::slist< std::pair<const Key, T> >& list,
402 bc::slist<std::pair<const Key, T> >::iterator itInsert,
403 bc::slist<std::pair<const Key, T> >::iterator itWhat )
405 list.insert_after( itInsert, *itWhat );
410 // The type T stored in the list must be swappable
413 bc::slist< std::pair<const Key, T> >& list,
414 bc::slist<std::pair<const Key, T> >::iterator itInsert,
415 bc::slist<std::pair<const Key, T> >::iterator itWhat )
417 std::pair<Key, T> newVal( itWhat->first, T() );
418 std::swap( list.insert( itInsert, newVal )->second, itWhat->second );
425 bc::slist< std::pair<const Key, T> >& list,
426 bc::slist<std::pair<const Key, T> >::iterator itInsert,
427 bc::slist<std::pair<const Key, T> >::iterator itWhat )
429 list.insert_after( itInsert, std::move( *itWhat ) );
436 <b>Advanced functions</b>
438 The library provides some advanced functions like \p erase_with(), \p find_with(),
439 that cannot be supported by all underlying containers.
440 The table below shows whether underlying container supports those functions
441 (the sign "+" means "container supports the function"):
446 <th>\p find_with</th>
447 <th>\p erse_with</th>
450 <td> \p std::list</td>
455 <td> \p std::map</td>
460 <td> \p std::unordered_map</td>
465 <td> \p boost::container::slist</td>
470 <td> \p boost::container::list</td>
475 <td> \p boost::container::map</td>
480 <td> \p boost::container::flat_map</td>
485 <td> \p boost::unordered_map</td>
492 template <class Container, typename... Options>
494 #ifdef CDS_DOXYGEN_INVOKED
495 : protected StripedSet<Container, Options...>
497 : protected details::make_striped_map< Container, Options...>::type
501 typedef typename details::make_striped_map< Container, Options...>::type base_class;
506 typedef typename base_class::default_options default_options;
507 typedef typename base_class::options options;
510 typedef Container underlying_container_type ; ///< original intrusive container type for the bucket
511 typedef typename base_class::bucket_type bucket_type ; ///< container type adapted for hash set
512 typedef typename bucket_type::value_type value_type ; ///< pair type (<tt> std::pair<key_type const, mapped_type> </tt>)
513 typedef typename value_type::first_type key_type ; ///< key type
514 typedef typename value_type::second_type mapped_type ; ///< mapped type
516 typedef typename base_class::hash hash ; ///< Hash functor
517 typedef typename base_class::item_counter item_counter ; ///< Item counter
518 typedef typename base_class::resizing_policy resizing_policy ; ///< Resizing policy
519 typedef typename base_class::allocator_type allocator_type ; ///< allocator type specified in options.
520 typedef typename base_class::mutex_policy mutex_policy ; ///< Mutex policy
524 typedef typename base_class::scoped_cell_lock scoped_cell_lock;
525 typedef typename base_class::scoped_full_lock scoped_full_lock;
526 typedef typename base_class::scoped_resize_lock scoped_resize_lock;
531 struct key_accessor {
532 key_type const& operator()( value_type const& p ) const
540 /// Default ctor. The initial capacity is 16.
545 /// Ctor with initial capacity specified
547 size_t nCapacity ///< Initial size of bucket table and lock array. Must be power of two, the minimum is 16.
548 ) : base_class( nCapacity )
551 /// Ctor with resizing policy (copy semantics)
553 This constructor initializes m_ResizingPolicy member with copy of \p resizingPolicy parameter
556 size_t nCapacity ///< Initial size of bucket table and lock array. Must be power of two, the minimum is 16.
557 ,resizing_policy const& resizingPolicy ///< Resizing policy
558 ) : base_class( nCapacity, resizingPolicy )
561 /// Ctor with resizing policy (move semantics)
563 This constructor initializes m_ResizingPolicy member moving \p resizingPolicy parameter
564 Move semantics is used. Available only for the compilers that supports C++11 rvalue reference.
567 size_t nCapacity ///< Initial size of bucket table and lock array. Must be power of two, the minimum is 16.
568 ,resizing_policy&& resizingPolicy ///< Resizing policy
569 ) : base_class( nCapacity, std::forward<resizing_policy>(resizingPolicy) )
572 /// Destructor destroys internal data
577 /// Inserts new node with key and default value
579 The function creates a node with \p key and default value, and then inserts the node created into the map.
582 - The \p key_type should be constructible from a value of type \p K.
583 In trivial case, \p K is equal to \p key_type.
584 - The \p mapped_type should be default-constructible.
586 Returns \p true if inserting successful, \p false otherwise.
588 template <typename K>
589 bool insert( K const& key )
591 return insert_with( key, [](value_type&){} );
596 The function creates a node with copy of \p val value
597 and then inserts the node created into the map.
600 - The \p key_type should be constructible from \p key of type \p K.
601 - The \p mapped_type should be constructible from \p val of type \p V.
603 Returns \p true if \p val is inserted into the set, \p false otherwise.
605 template <typename K, typename V>
606 bool insert( K const& key, V const& val )
608 return insert_with( key, [&val](value_type& item) { item.second = val ; } );
611 /// Inserts new node and initialize it by a functor
613 This function inserts new node with key \p key and if inserting is successful then it calls
614 \p func functor with signature
617 void operator()( value_type& item );
621 The argument \p item of user-defined functor \p func is the reference
622 to the map's item inserted:
623 - <tt>item.first</tt> is a const reference to item's key that cannot be changed.
624 - <tt>item.second</tt> is a reference to item's value that may be changed.
626 The key_type should be constructible from value of type \p K.
628 The function allows to split creating of new item into two part:
629 - create item from \p key;
630 - insert new item into the map;
631 - if inserting is successful, initialize the value of item by calling \p func functor
633 This can be useful if complete initialization of object of \p mapped_type is heavyweight and
634 it is preferable that the initialization should be completed only if inserting is successful.
636 template <typename K, typename Func>
637 bool insert_with( const K& key, Func func )
639 return base_class::insert( key, func );
642 /// For key \p key inserts data of type \p mapped_type created in-place from \p args
644 Returns \p true if inserting successful, \p false otherwise.
646 template <typename K, typename... Args>
647 bool emplace( K&& key, Args&&... args )
651 size_t nHash = base_class::hashing( std::forward<K>(key));
652 bucket_type * pBucket;
654 scoped_cell_lock sl( base_class::m_MutexPolicy, nHash );
655 pBucket = base_class::bucket( nHash );
657 bOk = pBucket->emplace( std::forward<K>(key), std::forward<Args>(args)...);
658 bResize = bOk && base_class::m_ResizingPolicy( ++base_class::m_ItemCounter, *this, *pBucket );
662 base_class::resize();
669 The operation performs inserting or changing data with lock-free manner.
671 If \p key is not found in the map, then \p key is inserted iff \p bAllowInsert is \p true.
672 Otherwise, the functor \p func is called with item found.
674 The functor signature is:
677 void operator()( bool bNew, value_type& item );
681 - \p bNew - \p true if the item has been inserted, \p false otherwise
682 - \p item - item of the map
684 Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successful,
685 \p second is true if new item has been added or \p false if the item with \p key
686 already is in the map.
688 template <typename K, typename Func>
689 std::pair<bool, bool> update( K const& key, Func func, bool bAllowInsert = true )
691 std::pair<bool, bool> result;
693 size_t nHash = base_class::hashing( key );
694 bucket_type * pBucket;
696 scoped_cell_lock sl( base_class::m_MutexPolicy, nHash );
697 pBucket = base_class::bucket( nHash );
699 result = pBucket->update( key, func, bAllowInsert );
700 bResize = result.first && result.second && base_class::m_ResizingPolicy( ++base_class::m_ItemCounter, *this, *pBucket );
704 base_class::resize();
708 template <typename K, typename Func>
709 CDS_DEPRECATED("ensure() is deprecated, use update() instead")
710 std::pair<bool, bool> ensure( K const& key, Func func )
712 return update( key, func, true );
716 /// Delete \p key from the map
717 /** \anchor cds_nonintrusive_StripedMap_erase
719 Return \p true if \p key is found and deleted, \p false otherwise
721 template <typename K>
722 bool erase( K const& key )
724 return base_class::erase( key );
727 /// Deletes the item from the map using \p pred predicate for searching
729 The function is an analog of \ref cds_nonintrusive_StripedMap_erase "erase(K const&)"
730 but \p pred is used for key comparing.
731 \p Less functor has the interface like \p std::less.
732 \p pred must imply the same element order as the comparator used for building the map.
734 @note This function is enabled if the compiler supports C++11
735 default template arguments for function template <b>and</b> the underlying container
736 supports \p %erase_with feature.
738 template < typename K, typename Less
739 ,typename Bucket = bucket_type, typename = typename std::enable_if< Bucket::has_erase_with >::type >
740 bool erase_with( K const& key, Less pred )
742 return erase_with( key, pred, [](value_type const&) {} );
745 /// Delete \p key from the map
746 /** \anchor cds_nonintrusive_StripedMap_erase_func
748 The function searches an item with key \p key, calls \p f functor
749 and deletes the item. If \p key is not found, the functor is not called.
751 The functor \p Func interface:
754 void operator()(value_type& item) { ... }
758 Return \p true if key is found and deleted, \p false otherwise
760 template <typename K, typename Func>
761 bool erase( K const& key, Func f )
763 return base_class::erase( key, f );
766 /// Deletes the item from the map using \p pred predicate for searching
768 The function is an analog of \ref cds_nonintrusive_StripedMap_erase_func "erase(K const&, Func)"
769 but \p pred is used for key comparing.
770 \p Less functor has the interface like \p std::less.
771 \p pred must imply the same element order as the comparator used for building the map.
773 @note This function is enabled if the compiler supports C++11
774 default template arguments for function template <b>and</b> the underlying container
775 supports \p %erase_with feature.
777 template <typename K, typename Less, typename Func
778 ,typename Bucket = bucket_type, typename = typename std::enable_if< Bucket::has_erase_with >::type >
779 bool erase_with( K const& key, Less pred, Func f )
782 return base_class::erase_with( key, cds::details::predicate_wrapper< value_type, Less, key_accessor >(), f );
785 /// Find the key \p key
786 /** \anchor cds_nonintrusive_StripedMap_find_func
788 The function searches the item with key equal to \p key and calls the functor \p f for item found.
789 The interface of \p Func functor is:
792 void operator()( value_type& item );
795 where \p item is the item found.
797 The functor may change \p item.second.
799 The function returns \p true if \p key is found, \p false otherwise.
801 template <typename K, typename Func>
802 bool find( K const& key, Func f )
804 return base_class::find( key, [&f]( value_type& pair, K const& ) mutable { f(pair); } );
807 /// Find the key \p val using \p pred predicate
809 The function is an analog of \ref cds_nonintrusive_StripedMap_find_func "find(K const&, Func)"
810 but \p pred is used for key comparing
811 \p Less has the interface like \p std::less.
812 \p pred must imply the same element order as the comparator used for building the set.
814 @note This function is enabled if the compiler supports C++11
815 default template arguments for function template <b>and</b> the underlying container
816 supports \p %find_with feature.
818 template <typename K, typename Less, typename Func
819 ,typename Bucket = bucket_type, typename = typename std::enable_if< Bucket::has_find_with >::type >
820 bool find_with( K const& key, Less pred, Func f )
823 return base_class::find_with( key, cds::details::predicate_wrapper< value_type, Less, key_accessor >(),
824 [&f]( value_type& pair, K const& ) mutable { f(pair); } );
827 /// Checks whether the map contains \p key
829 The function searches the item with key equal to \p key
830 and returns \p true if it is found, and \p false otherwise.
832 template <typename K>
833 bool contains( K const& key )
835 return base_class::contains( key );
838 template <typename K>
839 CDS_DEPRECATED("use contains()")
840 bool find( K const& key )
842 return contains( key );
846 /// Checks whether the set contains \p key using \p pred predicate for searching
848 The function is similar to <tt>contains( key )</tt> but \p pred is used for key comparing.
849 \p Less functor has the interface like \p std::less.
850 \p Less must imply the same element order as the comparator used for building the set.
852 @note This function is enabled if the compiler supports C++11
853 default template arguments for function template <b>and</b> the underlying container
854 supports \p %contains() feature.
856 template <typename K, typename Less
857 ,typename Bucket = bucket_type, typename = typename std::enable_if< Bucket::has_find_with >::type >
858 bool contains( K const& key, Less pred )
861 return base_class::contains( key, cds::details::predicate_wrapper< value_type, Less, key_accessor >() );
864 template <typename K, typename Less
865 ,typename Bucket = bucket_type, typename = typename std::enable_if< Bucket::has_find_with >::type >
866 CDS_DEPRECATED("use contains()")
867 bool find_with( K const& key, Less pred )
869 return contains( key, pred );
879 /// Checks if the map is empty
881 Emptiness is checked by item counting: if item count is zero then the map is empty.
885 return base_class::empty();
888 /// Returns item count in the map
891 return base_class::size();
894 /// Returns the size of hash table
896 The hash table size is non-constant and can be increased via resizing.
898 size_t bucket_count() const
900 return base_class::bucket_count();
903 /// Returns lock array size
905 The lock array size is constant.
907 size_t lock_count() const
909 return base_class::lock_count();
912 /// Returns resizing policy object
913 resizing_policy& get_resizing_policy()
915 return base_class::get_resizing_policy();
918 /// Returns resizing policy (const version)
919 resizing_policy const& get_resizing_policy() const
921 return base_class::get_resizing_policy();
925 }} // namespace cds::container
927 #endif // #ifndef CDSLIB_CONTAINER_STRIPED_MAP_H