3 #ifndef CDSLIB_INTRUSIVE_DETAILS_MICHAEL_SET_BASE_H
4 #define CDSLIB_INTRUSIVE_DETAILS_MICHAEL_SET_BASE_H
6 #include <cds/intrusive/details/base.h>
7 #include <cds/opt/compare.h>
8 #include <cds/opt/hash.h>
9 #include <cds/algo/bitop.h>
10 #include <cds/algo/atomic.h>
12 namespace cds { namespace intrusive {
14 /// MichaelHashSet related definitions
15 /** @ingroup cds_intrusive_helper
17 namespace michael_set {
20 struct implementation_tag;
23 /// MichaelHashSet traits
27 Hash function converts the key fields of struct \p T stored in the hash-set
28 into value of type \p size_t called hash value that is an index of hash table.
30 This is mandatory type and has no predefined one.
32 typedef opt::none hash;
36 The item counting is an important part of \p MichaelHashSet algorithm:
37 the \p empty() member function depends on correct item counting.
38 Therefore, \p atomicity::empty_item_counter is not allowed as a type of the option.
40 Default is \p atomicity::item_counter.
42 typedef cds::atomicity::item_counter item_counter;
44 /// Bucket table allocator
46 Allocator for bucket table. Default is \ref CDS_DEFAULT_ALLOCATOR
47 The allocator uses only in constructor for allocating bucket table
48 and in destructor for destroying bucket table
50 typedef CDS_DEFAULT_ALLOCATOR allocator;
53 /// Metafunction converting option list to traits struct
56 - \p opt::hash - mandatory option, specifies hash functor.
57 - \p opt::item_counter - optional, specifies item counting policy. See \p traits::item_counter
59 - \p opt::allocator - optional, bucket table allocator. Default is \ref CDS_DEFAULT_ALLOCATOR.
61 template <typename... Options>
63 typedef typename cds::opt::make_options< traits, Options...>::type type; ///< Metafunction result
68 static inline size_t init_hash_bitmask( size_t nMaxItemCount, size_t nLoadFactor )
70 if ( nLoadFactor == 0 )
72 if ( nMaxItemCount == 0 )
74 const size_t nBucketCount = (size_t)( nMaxItemCount / nLoadFactor );
75 const size_t nLog2 = cds::bitop::MSB( nBucketCount );
77 return (( size_t( 1 << nLog2 ) < nBucketCount ? size_t( 1 << (nLog2 + 1) ) : size_t( 1 << nLog2 ))) - 1;
80 template <typename OrderedList, bool IsConst>
81 struct list_iterator_selector;
83 template <typename OrderedList>
84 struct list_iterator_selector< OrderedList, false>
86 typedef OrderedList * bucket_ptr;
87 typedef typename OrderedList::iterator type;
90 template <typename OrderedList>
91 struct list_iterator_selector< OrderedList, true>
93 typedef OrderedList const * bucket_ptr;
94 typedef typename OrderedList::const_iterator type;
97 template <typename OrderedList, bool IsConst>
100 friend class iterator < OrderedList, !IsConst >;
102 typedef OrderedList bucket_type;
103 typedef typename list_iterator_selector< bucket_type, IsConst>::bucket_ptr bucket_ptr;
104 typedef typename list_iterator_selector< bucket_type, IsConst>::type list_iterator;
106 bucket_ptr m_pCurBucket;
107 list_iterator m_itList;
108 bucket_ptr m_pEndBucket;
112 if ( m_pCurBucket < m_pEndBucket ) {
113 if ( ++m_itList != m_pCurBucket->end() )
115 while ( ++m_pCurBucket < m_pEndBucket ) {
116 m_itList = m_pCurBucket->begin();
117 if ( m_itList != m_pCurBucket->end() )
121 m_pCurBucket = m_pEndBucket - 1;
122 m_itList = m_pCurBucket->end();
126 typedef typename list_iterator::value_ptr value_ptr;
127 typedef typename list_iterator::value_ref value_ref;
131 : m_pCurBucket( nullptr )
133 , m_pEndBucket( nullptr )
136 iterator( list_iterator const& it, bucket_ptr pFirst, bucket_ptr pLast )
137 : m_pCurBucket( pFirst )
139 , m_pEndBucket( pLast )
141 if ( it == pFirst->end() )
145 iterator( iterator const& src )
146 : m_pCurBucket( src.m_pCurBucket )
147 , m_itList( src.m_itList )
148 , m_pEndBucket( src.m_pEndBucket )
151 value_ptr operator ->() const
153 assert( m_pCurBucket != nullptr );
154 return m_itList.operator ->();
157 value_ref operator *() const
159 assert( m_pCurBucket != nullptr );
160 return m_itList.operator *();
164 iterator& operator ++()
170 iterator& operator = (const iterator& src)
172 m_pCurBucket = src.m_pCurBucket;
173 m_pEndBucket = src.m_pEndBucket;
174 m_itList = src.m_itList;
178 bucket_ptr bucket() const
180 return m_pCurBucket != m_pEndBucket ? m_pCurBucket : nullptr;
184 bool operator ==(iterator<bucket_type, C> const& i) const
186 return m_pCurBucket == i.m_pCurBucket && m_itList == i.m_itList;
189 bool operator !=(iterator<OrderedList, C> const& i ) const
191 return !( *this == i );
197 } // namespace michael_set
200 // Forward declarations
201 template <class GC, class OrderedList, class Traits = michael_set::traits>
202 class MichaelHashSet;
205 }} // namespace cds::intrusive
207 #endif // #ifndef CDSLIB_INTRUSIVE_DETAILS_MICHAEL_SET_BASE_H