-//$$CDS-header$$
-
-#ifndef __CDS_CONTAINER_ELLEN_BINTREE_MAP_IMPL_H
-#define __CDS_CONTAINER_ELLEN_BINTREE_MAP_IMPL_H
-
-#include <type_traits>
-#include <cds/container/details/ellen_bintree_base.h>
-#include <cds/intrusive/impl/ellen_bintree.h>
-#include <cds/details/functor_wrapper.h>
-#include <cds/container/details/guarded_ptr_cast.h>
-
-namespace cds { namespace container {
-
- /// Map based on Ellen's et al binary search tree
- /** @ingroup cds_nonintrusive_map
- @ingroup cds_nonintrusive_tree
- @anchor cds_container_EllenBinTreeMap
-
- Source:
- - [2010] F.Ellen, P.Fatourou, E.Ruppert, F.van Breugel "Non-blocking Binary Search Tree"
-
- %EllenBinTreeMap is an unbalanced leaf-oriented binary search tree that implements the <i>map</i>
- abstract data type. Nodes maintains child pointers but not parent pointers.
- Every internal node has exactly two children, and all data of type <tt>std::pair<Key const, T></tt>
- currently in the tree are stored in the leaves. Internal nodes of the tree are used to direct \p find
- operation along the path to the correct leaf. The keys (of \p Key type) stored in internal nodes
- may or may not be in the map.
- Unlike \ref cds_container_EllenBinTreeSet "EllenBinTreeSet" keys are not a part of \p T type.
- The map can be represented as a set containing <tt>std::pair< Key const, T> </tt> values.
-
- Due to \p extract_min and \p extract_max member functions the \p %EllenBinTreeMap can act as
- a <i>priority queue</i>. In this case you should provide unique compound key, for example,
- the priority value plus some uniformly distributed random value.
-
- @warning Recall the tree is <b>unbalanced</b>. The complexity of operations is <tt>O(log N)</tt>
- for uniformly distributed random keys, but in worst case the complexity is <tt>O(N)</tt>.
-
- @note In the current implementation we do not use helping technique described in original paper.
- So, the current implementation is near to fine-grained lock-based tree.
- Helping will be implemented in future release
-
- <b>Template arguments</b> :
- - \p GC - safe memory reclamation (i.e. light-weight garbage collector) type, like cds::gc::HP, cds::gc::PTB
- Note that cds::gc::HRC is not supported.
- - \p Key - key type
- - \p T - value type to be stored in tree's leaf nodes.
- - \p Traits - type traits. See ellen_bintree::type_traits for explanation.
-
- It is possible to declare option-based tree with ellen_bintree::make_map_traits metafunction
- instead of \p Traits template argument.
- Template argument list \p Options of ellen_bintree::make_map_traits metafunction are:
- - opt::compare - key compare functor. No default functor is provided.
- If the option is not specified, \p %opt::less is used.
- - opt::less - specifies binary predicate used for key compare. At least \p %opt::compare or \p %opt::less should be defined.
- - opt::item_counter - the type of item counting feature. Default is \ref atomicity::empty_item_counter that is no item counting.
- - opt::memory_model - C++ memory ordering model. Can be opt::v::relaxed_ordering (relaxed memory model, the default)
- or opt::v::sequential_consistent (sequentially consisnent memory model).
- - opt::allocator - the allocator used for \ref ellen_bintree::map_node "leaf nodes" which contains data.
- Default is \ref CDS_DEFAULT_ALLOCATOR.
- - opt::node_allocator - the allocator used for \ref ellen_bintree::internal_node "internal nodes".
- Default is \ref CDS_DEFAULT_ALLOCATOR.
- - ellen_bintree::update_desc_allocator - an allocator of \ref ellen_bintree::update_desc "update descriptors",
- default is \ref CDS_DEFAULT_ALLOCATOR.
- Note that update descriptor is helping data structure with short lifetime and it is good candidate for pooling.
- The number of simultaneously existing descriptors is a relatively small number limited the number of threads
- working with the tree and GC buffer size.
- Therefore, a bounded lock-free container like \p cds::container::VyukovMPMCCycleQueue is good choice for the free-list
- of update descriptors, see cds::memory::vyukov_queue_pool free-list implementation.
- Also notice that size of update descriptor is not dependent on the type of data
- stored in the tree so single free-list object can be used for several EllenBinTree-based object.
- - opt::stat - internal statistics. Available types: ellen_bintree::stat, ellen_bintree::empty_stat (the default)
- - opt::copy_policy - key copy policy defines a functor to copy leaf node's key to internal node.
- By default, assignment operator is used.
- The copy functor interface is:
- \code
- struct copy_functor {
- void operator()( Key& dest, Key const& src );
- };
- \endcode
-
- @note Do not include <tt><cds/container/ellen_bintree_map_impl.h></tt> header file directly.
- There are header file for each GC type:
- - <tt><cds/container/ellen_bintree_map_hp.h></tt> - for Hazard Pointer GC cds::gc::HP
- - <tt><cds/container/ellen_bintree_map_ptb.h></tt> - for Pass-the-Buck GC cds::gc::PTB
- - <tt><cds/container/ellen_bintree_map_rcu.h></tt> - for RCU GC
- (see \ref cds_container_EllenBinTreeMap_rcu "RCU-based EllenBinTreeMap")
- */
- template <
- class GC,
- typename Key,
- typename T,
-#ifdef CDS_DOXYGEN_INVOKED
- class Traits = ellen_bintree::type_traits
-#else
- class Traits
-#endif
- >
- class EllenBinTreeMap
-#ifdef CDS_DOXYGEN_INVOKED
- : public cds::intrusive::EllenBinTree< GC, Key, T, Traits >
-#else
- : public ellen_bintree::details::make_ellen_bintree_map< GC, Key, T, Traits >::type
-#endif
- {
- //@cond
- typedef ellen_bintree::details::make_ellen_bintree_map< GC, Key, T, Traits > maker;
- typedef typename maker::type base_class;
- //@endcond
- public:
- typedef GC gc ; ///< Garbage collector
- typedef Key key_type ; ///< type of a key stored in the map
- typedef T mapped_type ; ///< type of value stored in the map
- typedef std::pair< key_type const, mapped_type > value_type ; ///< Key-value pair stored in leaf node of the mp
- typedef Traits options ; ///< Traits template parameter
-
-# ifdef CDS_DOXYGEN_INVOKED
- typedef implementation_defined key_comparator ; ///< key compare functor based on opt::compare and opt::less option setter.
-# else
- typedef typename maker::intrusive_type_traits::compare key_comparator;
-# endif
- typedef typename base_class::item_counter item_counter ; ///< Item counting policy used
- typedef typename base_class::memory_model memory_model ; ///< Memory ordering. See cds::opt::memory_model option
- typedef typename base_class::node_allocator node_allocator_type ; ///< allocator for maintaining internal node
- typedef typename base_class::stat stat ; ///< internal statistics type
- typedef typename options::copy_policy copy_policy ; ///< key copy policy
-
- typedef typename options::allocator allocator_type ; ///< Allocator for leaf nodes
- typedef typename base_class::node_allocator node_allocator ; ///< Internal node allocator
- typedef typename base_class::update_desc_allocator update_desc_allocator ; ///< Update descriptor allocator
-
- protected:
- //@cond
- typedef typename base_class::value_type leaf_node;
- typedef typename base_class::internal_node internal_node;
- typedef typename base_class::update_desc update_desc;
-
- typedef typename maker::cxx_leaf_node_allocator cxx_leaf_node_allocator;
-
- typedef std::unique_ptr< leaf_node, typename maker::leaf_deallocator > scoped_node_ptr;
- //@endcond
-
- public:
- /// Guarded pointer
- typedef cds::gc::guarded_ptr< gc, leaf_node, value_type, details::guarded_ptr_cast_set<leaf_node, value_type> > guarded_ptr;
-
- public:
- /// Default constructor
- EllenBinTreeMap()
- : base_class()
- {
- //static_assert( (std::is_same<gc, cds::gc::HP>::value || std::is_same<gc, cds::gc::PTB>::value), "GC must be cds::gc::HP or cds:gc::PTB" );
- }
-
- /// Clears the map
- ~EllenBinTreeMap()
- {}
-
- /// Inserts new node with key and default value
- /**
- The function creates a node with \p key and default value, and then inserts the node created into the map.
-
- Preconditions:
- - The \ref key_type should be constructible from a value of type \p K.
- In trivial case, \p K is equal to \ref key_type.
- - The \ref mapped_type should be default-constructible.
-
- Returns \p true if inserting successful, \p false otherwise.
- */
- template <typename K>
- bool insert( K const& key )
- {
- return insert_key( key, [](value_type&){} );
- }
-
- /// Inserts new node
- /**
- The function creates a node with copy of \p val value
- and then inserts the node created into the map.
-
- Preconditions:
- - The \ref key_type should be constructible from \p key of type \p K.
- - The \ref value_type should be constructible from \p val of type \p V.
-
- Returns \p true if \p val is inserted into the map, \p false otherwise.
- */
- template <typename K, typename V>
- bool insert( K const& key, V const& val )
- {
- scoped_node_ptr pNode( cxx_leaf_node_allocator().New( key, val ));
- if ( base_class::insert( *pNode ))
- {
- pNode.release();
- return true;
- }
- return false;
- }
-
- /// Inserts new node and initialize it by a functor
- /**
- This function inserts new node with key \p key and if inserting is successful then it calls
- \p func functor with signature
- \code
- struct functor {
- void operator()( value_type& item );
- };
- \endcode
-
- The argument \p item of user-defined functor \p func is the reference
- to the map's item inserted:
- - <tt>item.first</tt> is a const reference to item's key that cannot be changed.
- - <tt>item.second</tt> is a reference to item's value that may be changed.
-
- The user-defined functor can be passed by reference using <tt>boost::ref</tt>
- and it is called only if inserting is successful.
-
- The key_type should be constructible from value of type \p K.
-
- The function allows to split creating of new item into two part:
- - create item from \p key;
- - insert new item into the map;
- - if inserting is successful, initialize the value of item by calling \p func functor
-
- This can be useful if complete initialization of object of \p value_type is heavyweight and
- it is preferable that the initialization should be completed only if inserting is successful.
- */
- template <typename K, typename Func>
- bool insert_key( const K& key, Func func )
- {
- scoped_node_ptr pNode( cxx_leaf_node_allocator().New( key ));
- if ( base_class::insert( *pNode, [&func]( leaf_node& item ) { cds::unref(func)( item.m_Value ); } )) {
- pNode.release();
- return true;
- }
- return false;
- }
-
- /// For key \p key inserts data of type \ref value_type constructed with <tt>std::forward<Args>(args)...</tt>
- /**
- Returns \p true if inserting successful, \p false otherwise.
- */
- template <typename K, typename... Args>
- bool emplace( K&& key, Args&&... args )
- {
- scoped_node_ptr pNode( cxx_leaf_node_allocator().New( std::forward<K>(key), std::forward<Args>(args)... ));
- if ( base_class::insert( *pNode )) {
- pNode.release();
- return true;
- }
- return false;
- }
-
- /// Ensures that the \p key exists in the map
- /**
- The operation performs inserting or changing data with lock-free manner.
-
- If the \p key not found in the map, then the new item created from \p key
- is inserted into the map (note that in this case the \ref key_type should be
- constructible from type \p K).
- Otherwise, the functor \p func is called with item found.
- The functor \p Func may be a function with signature:
- \code
- void func( bool bNew, value_type& item );
- \endcode
- or a functor:
- \code
- struct my_functor {
- void operator()( bool bNew, value_type& item );
- };
- \endcode
-
- with arguments:
- - \p bNew - \p true if the item has been inserted, \p false otherwise
- - \p item - item of the list
-
- The functor may change any fields of the \p item.second that is \ref value_type.
-
- You may pass \p func argument by reference using <tt>boost::ref</tt>.
-
- Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successfull,
- \p second is true if new item has been added or \p false if the item with \p key
- already is in the list.
- */
- template <typename K, typename Func>
- std::pair<bool, bool> ensure( K const& key, Func func )
- {
- scoped_node_ptr pNode( cxx_leaf_node_allocator().New( key ));
- std::pair<bool, bool> res = base_class::ensure( *pNode,
- [&func](bool bNew, leaf_node& item, leaf_node const& ){ cds::unref(func)( bNew, item.m_Value ); }
- );
- if ( res.first && res.second )
- pNode.release();
- return res;
- }
-
- /// Delete \p key from the map
- /**\anchor cds_nonintrusive_EllenBinTreeMap_erase_val
-
- Return \p true if \p key is found and deleted, \p false otherwise
- */
- template <typename K>
- bool erase( K const& key )
- {
- return base_class::erase(key);
- }
-
- /// Deletes the item from the map using \p pred predicate for searching
- /**
- The function is an analog of \ref cds_nonintrusive_EllenBinTreeMap_erase_val "erase(K const&)"
- but \p pred is used for key comparing.
- \p Less functor has the interface like \p std::less.
- \p Less must imply the same element order as the comparator used for building the map.
- */
- template <typename K, typename Less>
- bool erase_with( K const& key, Less pred )
- {
- return base_class::erase_with( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::key_accessor >());
- }
-
- /// Delete \p key from the map
- /** \anchor cds_nonintrusive_EllenBinTreeMap_erase_func
-
- The function searches an item with key \p key, calls \p f functor
- and deletes the item. If \p key is not found, the functor is not called.
-
- The functor \p Func interface:
- \code
- struct extractor {
- void operator()(value_type& item) { ... }
- };
- \endcode
- The functor may be passed by reference using <tt>boost:ref</tt>
-
- Return \p true if key is found and deleted, \p false otherwise
- */
- template <typename K, typename Func>
- bool erase( K const& key, Func f )
- {
- return base_class::erase( key, [&f]( leaf_node& node) { cds::unref(f)( node.m_Value ); } );
- }
-
- /// Deletes the item from the map using \p pred predicate for searching
- /**
- The function is an analog of \ref cds_nonintrusive_EllenBinTreeMap_erase_func "erase(K const&, Func)"
- but \p pred is used for key comparing.
- \p Less functor has the interface like \p std::less.
- \p Less must imply the same element order as the comparator used for building the map.
- */
- template <typename K, typename Less, typename Func>
- bool erase_with( K const& key, Less pred, Func f )
- {
- return base_class::erase_with( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::key_accessor >(),
- [&f]( leaf_node& node) { cds::unref(f)( node.m_Value ); } );
- }
-
- /// Extracts an item with minimal key from the map
- /**
- If the map is not empty, the function returns \p true, \p result contains a pointer to minimum value.
- If the map is empty, the function returns \p false, \p result is left unchanged.
-
- @note Due the concurrent nature of the map, the function extracts <i>nearly</i> minimum key.
- It means that the function gets leftmost leaf of the tree and tries to unlink it.
- During unlinking, a concurrent thread may insert an item with key less than leftmost item's key.
- So, the function returns the item with minimum key at the moment of tree traversing.
-
- The guarded pointer \p result prevents deallocation of returned item,
- see cds::gc::guarded_ptr for explanation.
- @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
- */
- bool extract_min( guarded_ptr& result )
- {
- return base_class::extract_min_( result.guard() );
- }
-
- /// Extracts an item with maximal key from the map
- /**
- If the map is not empty, the function returns \p true, \p result contains a pointer to maximal value.
- If the map is empty, the function returns \p false, \p result is left unchanged.
-
- @note Due the concurrent nature of the map, the function extracts <i>nearly</i> maximal key.
- It means that the function gets rightmost leaf of the tree and tries to unlink it.
- During unlinking, a concurrent thread may insert an item with key great than leftmost item's key.
- So, the function returns the item with maximum key at the moment of tree traversing.
-
- The guarded pointer \p result prevents deallocation of returned item,
- see cds::gc::guarded_ptr for explanation.
- @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
- */
- bool extract_max( guarded_ptr& result )
- {
- return base_class::extract_max_( result.guard() );
- }
-
- /// Extracts an item from the tree
- /** \anchor cds_nonintrusive_EllenBinTreeMap_extract
- The function searches an item with key equal to \p key in the tree,
- unlinks it, and returns pointer to an item found in \p result parameter.
- If the item is not found the function returns \p false.
-
- The guarded pointer \p result prevents deallocation of returned item,
- see cds::gc::guarded_ptr for explanation.
- @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
- */
- template <typename Q>
- bool extract( guarded_ptr& result, Q const& key )
- {
- return base_class::extract_( result.guard(), key );
- }
-
- /// Extracts an item from the map using \p pred for searching
- /**
- The function is an analog of \ref cds_nonintrusive_EllenBinTreeMap_extract "extract(guarded_ptr&, Q const&)"
- but \p pred is used for key compare.
- \p Less has the interface like \p std::less.
- \p pred must imply the same element order as the comparator used for building the map.
- */
- template <typename Q, typename Less>
- bool extract_with( guarded_ptr& result, Q const& key, Less pred )
- {
- return base_class::extract_with_( result.guard(), key,
- cds::details::predicate_wrapper< leaf_node, Less, typename maker::key_accessor >());
- }
-
- /// Find the key \p key
- /** \anchor cds_nonintrusive_EllenBinTreeMap_find_cfunc
-
- The function searches the item with key equal to \p key and calls the functor \p f for item found.
- The interface of \p Func functor is:
- \code
- struct functor {
- void operator()( value_type& item );
- };
- \endcode
- where \p item is the item found.
-
- You can pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
-
- The functor may change \p item.second.
-
- The function returns \p true if \p key is found, \p false otherwise.
- */
- template <typename K, typename Func>
- bool find( K const& key, Func f )
- {
- return base_class::find( key, [&f](leaf_node& item, K const& ) { cds::unref(f)( item.m_Value );});
- }
-
- /// Finds the key \p val using \p pred predicate for searching
- /**
- The function is an analog of \ref cds_nonintrusive_EllenBinTreeMap_find_cfunc "find(K const&, Func)"
- but \p pred is used for key comparing.
- \p Less functor has the interface like \p std::less.
- \p Less must imply the same element order as the comparator used for building the map.
- */
- template <typename K, typename Less, typename Func>
- bool find_with( K const& key, Less pred, Func f )
- {
- return base_class::find_with( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::key_accessor >(),
- [&f](leaf_node& item, K const& ) { cds::unref(f)( item.m_Value );});
- }
-
- /// Find the key \p key
- /** \anchor cds_nonintrusive_EllenBinTreeMap_find_val
-
- The function searches the item with key equal to \p key
- and returns \p true if it is found, and \p false otherwise.
- */
- template <typename K>
- bool find( K const& key )
- {
- return base_class::find( key );
- }
-
- /// Finds the key \p val using \p pred predicate for searching
- /**
- The function is an analog of \ref cds_nonintrusive_EllenBinTreeMap_find_val "find(K const&)"
- but \p pred is used for key comparing.
- \p Less functor has the interface like \p std::less.
- \p Less must imply the same element order as the comparator used for building the map.
- */
- template <typename K, typename Less>
- bool find_with( K const& key, Less pred )
- {
- return base_class::find_with( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::key_accessor >() );
- }
-
- /// Finds \p key and returns the item found
- /** @anchor cds_nonintrusive_EllenBinTreeMap_get
- The function searches the item with key equal to \p key and returns the item found in \p result parameter.
- The function returns \p true if \p key is found, \p false otherwise.
-
- The guarded pointer \p result prevents deallocation of returned item,
- see cds::gc::guarded_ptr for explanation.
- @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
- */
- template <typename Q>
- bool get( guarded_ptr& result, Q const& key )
- {
- return base_class::get_( result.guard(), key );
- }
-
- /// Finds \p key with predicate \p pred and returns the item found
- /**
- The function is an analog of \ref cds_nonintrusive_EllenBinTreeMap_get "get(guarded_ptr&, Q const&)"
- but \p pred is used for key comparing.
- \p Less functor has the interface like \p std::less.
- \p pred must imply the same element order as the comparator used for building the map.
- */
- template <typename Q, typename Less>
- bool get_with( guarded_ptr& result, Q const& key, Less pred )
- {
- return base_class::get_with_( result.guard(), key,
- cds::details::predicate_wrapper< leaf_node, Less, typename maker::key_accessor >() );
- }
-
- /// Clears the map
- void clear()
- {
- base_class::clear();
- }
-
- /// Checks if the map is empty
- /**
- Emptiness is checked by item counting: if item count is zero then the map is empty.
- */
- bool empty() const
- {
- return base_class::empty();
- }
-
- /// Returns item count in the map
- size_t size() const
- {
- return base_class::size();
- }
-
- /// Returns const reference to internal statistics
- stat const& statistics() const
- {
- return base_class::statistics();
- }
-
- /// Checks internal consistency (not atomic, not thread-safe)
- /**
- The debugging function to check internal consistency of the tree.
- */
- bool check_consistency() const
- {
- return base_class::check_consistency();
- }
-
- };
-}} // namespace cds::container
-
-#endif //#ifndef __CDS_CONTAINER_ELLEN_BINTREE_MAP_IMPL_H
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