3 #ifndef __CDS_CONTAINER_MICHAEL_KVLIST_NOGC_H
4 #define __CDS_CONTAINER_MICHAEL_KVLIST_NOGC_H
7 #include <cds/container/details/michael_list_base.h>
8 #include <cds/intrusive/michael_list_nogc.h>
9 #include <cds/container/details/make_michael_kvlist.h>
11 namespace cds { namespace container {
16 template <typename K, typename T, class Traits>
17 struct make_michael_kvlist_nogc: public make_michael_kvlist<gc::nogc, K, T, Traits>
19 typedef make_michael_kvlist<cds::gc::nogc, K, T, Traits> base_maker;
20 typedef typename base_maker::node_type node_type;
22 struct intrusive_traits: public base_maker::intrusive_traits
24 typedef typename base_maker::node_deallocator disposer;
27 typedef intrusive::MichaelList<cds::gc::nogc, node_type, intrusive_traits> type;
30 } // namespace details
33 /// Michael's ordered list (key-value pair, template specialization for gc::nogc)
34 /** @ingroup cds_nonintrusive_list
36 This specialization is intended for so-called persistent usage when no item
37 reclamation may be performed. The class does not support deleting of list item.
39 Usually, ordered single-linked list is used as a building block for the hash table implementation.
40 The complexity of searching is <tt>O(N)</tt>.
42 See \ref cds_nonintrusive_MichaelList_gc "MichaelList" for description of template parameters.
44 The interface of the specialization is a little different.
49 #ifdef CDS_DOXYGEN_INVOKED
50 typename Traits = michael_list::traits
55 class MichaelKVList<gc::nogc, Key, Value, Traits>:
56 #ifdef CDS_DOXYGEN_INVOKED
57 protected intrusive::MichaelList< gc::nogc, implementation_defined, Traits >
59 protected details::make_michael_kvlist_nogc< Key, Value, Traits >::type
63 typedef details::make_michael_kvlist_nogc< Key, Value, Traits > maker;
64 typedef typename maker::type base_class;
68 typedef cds::gc::nogc gc; ///< Garbage collector used
69 typedef Traits traits; ///< List traits
71 #ifdef CDS_DOXYGEN_INVOKED
72 typedef Key key_type ; ///< Key type
73 typedef Value mapped_type ; ///< Type of value stored in the list
74 typedef std::pair<key_type const, mapped_type> value_type ; ///< key/value pair stored in the list
76 typedef typename maker::key_type key_type;
77 typedef typename maker::value_type mapped_type;
78 typedef typename maker::pair_type value_type;
81 typedef typename base_class::back_off back_off; ///< Back-off strategy used
82 typedef typename maker::allocator_type allocator_type; ///< Allocator type used for allocate/deallocate the nodes
83 typedef typename base_class::item_counter item_counter; ///< Item counting policy used
84 typedef typename maker::key_comparator key_comparator; ///< key comparison functor
85 typedef typename base_class::memory_model memory_model; ///< Memory ordering. See cds::opt::memory_model option
89 typedef typename base_class::value_type node_type;
90 typedef typename maker::cxx_allocator cxx_allocator;
91 typedef typename maker::node_deallocator node_deallocator;
92 typedef typename maker::intrusive_traits::compare intrusive_key_comparator;
94 typedef typename base_class::atomic_node_ptr head_type;
100 static node_type * alloc_node(const K& key)
102 return cxx_allocator().New( key );
105 template <typename K, typename V>
106 static node_type * alloc_node( const K& key, const V& val )
108 return cxx_allocator().New( key, val );
111 template <typename K, typename... Args>
112 static node_type * alloc_node( K&& key, Args&&... args )
114 return cxx_allocator().MoveNew( std::forward<K>(key), std::forward<Args>(args)... );
117 static void free_node( node_type * pNode )
119 cxx_allocator().Delete( pNode );
122 struct node_disposer {
123 void operator()( node_type * pNode )
128 typedef std::unique_ptr< node_type, node_disposer > scoped_node_ptr;
132 return base_class::m_pHead;
135 head_type const& head() const
137 return base_class::m_pHead;
143 template <bool IsConst>
144 class iterator_type: protected base_class::template iterator_type<IsConst>
146 typedef typename base_class::template iterator_type<IsConst> iterator_base;
148 iterator_type( head_type const& refNode )
149 : iterator_base( refNode )
152 explicit iterator_type( const iterator_base& it )
153 : iterator_base( it )
156 friend class MichaelKVList;
159 explicit iterator_type( node_type& pNode )
160 : iterator_base( &pNode )
164 typedef typename cds::details::make_const_type<mapped_type, IsConst>::reference value_ref;
165 typedef typename cds::details::make_const_type<mapped_type, IsConst>::pointer value_ptr;
167 typedef typename cds::details::make_const_type<value_type, IsConst>::reference pair_ref;
168 typedef typename cds::details::make_const_type<value_type, IsConst>::pointer pair_ptr;
174 iterator_type( const iterator_type& src )
175 : iterator_base( src )
178 key_type const& key() const
180 typename iterator_base::value_ptr p = iterator_base::operator ->();
181 assert( p != nullptr );
182 return p->m_Data.first;
185 value_ref val() const
187 typename iterator_base::value_ptr p = iterator_base::operator ->();
188 assert( p != nullptr );
189 return p->m_Data.second;
192 pair_ptr operator ->() const
194 typename iterator_base::value_ptr p = iterator_base::operator ->();
195 return p ? &(p->m_Data) : nullptr;
198 pair_ref operator *() const
200 typename iterator_base::value_ref p = iterator_base::operator *();
205 iterator_type& operator ++()
207 iterator_base::operator ++();
212 iterator_type operator ++(int)
214 return iterator_base::operator ++(0);
218 bool operator ==(iterator_type<C> const& i ) const
220 return iterator_base::operator ==(i);
223 bool operator !=(iterator_type<C> const& i ) const
225 return iterator_base::operator !=(i);
233 The forward iterator for Michael's list based on gc::nogc has pre- and post-increment operators.
235 The iterator interface to access item data:
236 - <tt> operator -> </tt> - returns a pointer to \ref value_type for iterator
237 - <tt> operator *</tt> - returns a reference (a const reference for \p const_iterator) to \ref value_type for iterator
238 - <tt> const key_type& key() </tt> - returns a key reference for iterator
239 - <tt> mapped_type& val() </tt> - retuns a value reference for iterator (const reference for \p const_iterator)
241 For both functions the iterator should not be equal to <tt> end() </tt>
243 typedef iterator_type<false> iterator;
245 /// Const forward iterator
247 For iterator's features and requirements see \ref iterator
249 typedef iterator_type<true> const_iterator;
251 /// Returns a forward iterator addressing the first element in a list
253 For empty list \code begin() == end() \endcode
257 return iterator( head() );
260 /// Returns an iterator that addresses the location succeeding the last element in a list
262 Do not use the value returned by <tt>end</tt> function to access any item.
263 Internally, <tt>end</tt> returning value equals to \p nullptr.
265 The returned value can be used only to control reaching the end of the list.
266 For empty list \code begin() == end() \endcode
273 /// Returns a forward const iterator addressing the first element in a list
275 const_iterator begin() const
277 return const_iterator( head() );
279 const_iterator cbegin()
281 return const_iterator( head() );
285 /// Returns an const iterator that addresses the location succeeding the last element in a list
287 const_iterator end() const
289 return const_iterator();
291 const_iterator cend()
293 return const_iterator();
299 iterator node_to_iterator( node_type * pNode )
302 return iterator( *pNode );
308 /// Default constructor
310 Initialize empty list
324 /// Inserts new node with key and default value
326 The function creates a node with \p key and default value, and then inserts the node created into the list.
329 - The \ref key_type should be constructible from value of type \p K.
330 In trivial case, \p K is equal to \ref key_type.
331 - The \ref mapped_type should be default-constructible.
333 Returns an iterator pointed to inserted value, or \p end() if inserting is failed
335 template <typename K>
336 iterator insert( const K& key )
338 return node_to_iterator( insert_at( head(), key ));
341 /// Inserts new node with a key and a value
343 The function creates a node with \p key and value \p val, and then inserts the node created into the list.
346 - The \ref key_type should be constructible from \p key of type \p K.
347 - The \ref mapped_type should be constructible from \p val of type \p V.
349 Returns an iterator pointed to inserted value, or \p end() if inserting is failed
351 template <typename K, typename V>
352 iterator insert( const K& key, const V& val )
354 // We cannot use insert with functor here
355 // because we cannot lock inserted node for updating
356 // Therefore, we use separate function
357 return node_to_iterator( insert_at( head(), key, val ));
360 /// Inserts new node and initialize it by a functor
362 This function inserts new node with key \p key and if inserting is successful then it calls
363 \p func functor with signature
364 \code void func( value_type& item );
366 void operator()( value_type& item );
370 The argument \p item of user-defined functor \p func is the reference
371 to the list's item inserted. <tt>item.second</tt> is a reference to item's value that may be changed.
372 User-defined functor \p func should guarantee that during changing item's value no any other changes
373 could be made on this list's item by concurrent threads.
374 The user-defined functor can be passed by reference using \p std::ref
375 and it is called only if the inserting is successful.
377 The key_type should be constructible from value of type \p K.
379 The function allows to split creating of new item into two part:
380 - create item from \p key;
381 - insert new item into the list;
382 - if inserting is successful, initialize the value of item by calling \p f functor
384 This can be useful if complete initialization of object of \p mapped_type is heavyweight and
385 it is preferable that the initialization should be completed only if inserting is successful.
387 Returns an iterator pointed to inserted value, or \p end() if inserting is failed
389 template <typename K, typename Func>
390 iterator insert_key( const K& key, Func func )
392 return node_to_iterator( insert_key_at( head(), key, func ));
395 /// Ensures that the key \p key exists in the list
397 The operation inserts new item if the key \p key is not found in the list.
398 Otherwise, the function returns an iterator that points to item found.
400 Returns <tt> std::pair<iterator, bool> </tt> where \p first is an iterator pointing to
401 item found or inserted, \p second is true if new item has been added or \p false if the item
402 already is in the list.
404 template <typename K>
405 std::pair<iterator, bool> ensure( const K& key )
407 std::pair< node_type *, bool > ret = ensure_at( head(), key );
408 return std::make_pair( node_to_iterator( ret.first ), ret.second );
411 /// Inserts data of type \ref mapped_type constructed with <tt>std::forward<Args>(args)...</tt>
413 Returns an iterator pointed to inserted value, or \p end() if inserting is failed
415 template <typename K, typename... Args>
416 iterator emplace( K&& key, Args&&... args )
418 return node_to_iterator( emplace_at( head(), std::forward<K>(key), std::forward<Args>(args)... ));
421 /// Find the key \p key
422 /** \anchor cds_nonintrusive_MichaelKVList_nogc_find
424 The function searches the item with key equal to \p key
425 and returns an iterator pointed to item found if the key is found,
426 and \ref end() otherwise
428 template <typename Q>
429 iterator find( Q const& key )
431 return node_to_iterator( find_at( head(), key, intrusive_key_comparator() ) );
434 /// Finds the key \p key using \p pred predicate for searching
436 The function is an analog of \ref cds_nonintrusive_MichaelKVList_nogc_find "find(Q const&)"
437 but \p pred is used for key comparing.
438 \p Less functor has the interface like \p std::less.
439 \p pred must imply the same element order as the comparator used for building the list.
441 template <typename Q, typename Less>
442 iterator find_with( Q const& key, Less pred )
444 return node_to_iterator( find_at( head(), key, typename maker::template less_wrapper<Less>::type() ) );
447 /// Check if the list is empty
450 return base_class::empty();
453 /// Returns list's item count
455 The value returned depends on item counter provided by \p Traits. For \p atomicity::empty_item_counter,
456 this function always returns 0.
458 @note Even if you use real item counter and it returns 0, this fact does not mean that the list
459 is empty. To check list emptyness use \p empty() method.
463 return base_class::size();
474 node_type * insert_node_at( head_type& refHead, node_type * pNode )
476 assert( pNode != nullptr );
477 scoped_node_ptr p( pNode );
478 if ( base_class::insert_at( refHead, *pNode ))
483 template <typename K>
484 node_type * insert_at( head_type& refHead, const K& key )
486 return insert_node_at( refHead, alloc_node( key ));
489 template <typename K, typename V>
490 node_type * insert_at( head_type& refHead, const K& key, const V& val )
492 return insert_node_at( refHead, alloc_node( key, val ));
495 template <typename K, typename Func>
496 node_type * insert_key_at( head_type& refHead, const K& key, Func f )
498 scoped_node_ptr pNode( alloc_node( key ));
500 if ( base_class::insert_at( refHead, *pNode )) {
502 return pNode.release();
507 template <typename K>
508 std::pair< node_type *, bool > ensure_at( head_type& refHead, const K& key )
510 scoped_node_ptr pNode( alloc_node( key ));
511 node_type * pItemFound = nullptr;
513 std::pair<bool, bool> ret = base_class::ensure_at( refHead, *pNode, [&pItemFound](bool, node_type& item, node_type&){ pItemFound = &item; });
514 assert( pItemFound != nullptr );
516 if ( ret.first && ret.second )
518 return std::make_pair( pItemFound, ret.second );
521 template <typename K, typename... Args>
522 node_type * emplace_at( head_type& refHead, K&& key, Args&&... args )
524 return insert_node_at( refHead, alloc_node( std::forward<K>(key), std::forward<Args>(args)... ));
527 template <typename K, typename Compare>
528 node_type * find_at( head_type& refHead, K const& key, Compare cmp )
530 return base_class::find_at( refHead, key, cmp );
535 }} // namespace cds::container
537 #endif // #ifndef __CDS_CONTAINER_MICHAEL_KVLIST_NOGC_H