--- /dev/null
+/*
+ This file is a part of libcds - Concurrent Data Structures library
+
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017
+
+ Source code repo: http://github.com/khizmax/libcds/
+ Download: http://sourceforge.net/projects/libcds/files/
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef CDSLIB_CONTAINER_IMPL_ELLEN_BINTREE_MAP_H
+#define CDSLIB_CONTAINER_IMPL_ELLEN_BINTREE_MAP_H
+
+#include <type_traits>
+#include <cds/container/details/ellen_bintree_base.h>
+#include <cds/intrusive/impl/ellen_bintree.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 the worst case the complexity is <tt>O(N)</tt>.
+
+ @note In the current implementation we do not use helping technique described in the original paper.
+ In Hazard Pointer schema helping is too complicated and does not give any observable benefits.
+ Instead of helping, when a thread encounters a concurrent operation it just spins waiting for
+ the operation done. Such solution allows greatly simplify implementation of the tree.
+
+ <b>Template arguments</b> :
+ - \p GC - safe memory reclamation (i.e. light-weight garbage collector) type, like \p cds::gc::HP, \p cds::gc::DHP
+ - \p Key - key type. Should be default-constructible
+ - \p T - value type to be stored in tree's leaf nodes.
+ - \p Traits - map traits, default is \p ellen_bintree::traits
+ It is possible to declare option-based tree with \p ellen_bintree::make_map_traits metafunction
+ instead of \p Traits template argument.
+
+ @note Do not include <tt><cds/container/impl/ellen_bintree_map.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_dhp.h></tt> - for Dynamic Hazard Pointer GC cds::gc::DHP
+ - <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::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 traits; ///< Map traits
+
+ static_assert( std::is_default_constructible<key_type>::value, "Key should be default constructible type");
+
+# ifdef CDS_DOXYGEN_INVOKED
+ typedef implementation_defined key_comparator; ///< key compare functor based on \p Traits::compare and \p Traits::less
+# else
+ typedef typename maker::intrusive_traits::compare key_comparator;
+# endif
+ typedef typename base_class::item_counter item_counter; ///< Item counting policy
+ typedef typename base_class::memory_model memory_model; ///< Memory ordering, see \p cds::opt::memory_model
+ 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 traits::copy_policy copy_policy; ///< key copy policy
+ typedef typename traits::back_off back_off; ///< Back-off strategy
+
+ typedef typename traits::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 typename gc::template guarded_ptr< leaf_node, value_type, details::guarded_ptr_cast_set<leaf_node, value_type> > guarded_ptr;
+
+ public:
+ /// Default constructor
+ EllenBinTreeMap()
+ : base_class()
+ {}
+
+ /// 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_with( 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 \p key_type should be constructible from \p key of type \p K.
+ - The \p 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 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_with( const K& key, Func func )
+ {
+ scoped_node_ptr pNode( cxx_leaf_node_allocator().New( key ));
+ if ( base_class::insert( *pNode, [&func]( leaf_node& item ) { func( item.m_Value ); } )) {
+ pNode.release();
+ return true;
+ }
+ return false;
+ }
+
+ /// For key \p key inserts data of type \p value_type created in-place from \p args
+ /**
+ 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().MoveNew( key_type( std::forward<K>(key)), mapped_type( std::forward<Args>(args)... )));
+ if ( base_class::insert( *pNode )) {
+ pNode.release();
+ return true;
+ }
+ return false;
+ }
+
+ /// Updates the node
+ /**
+ The operation performs inserting or changing data with lock-free manner.
+
+ If the item \p val is not found in the map, then \p val is inserted iff \p bAllowInsert is \p true.
+ Otherwise, the functor \p func is called with item found.
+ The functor \p func signature is:
+ \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 map
+
+ The functor may change any fields of the \p item.second that is \ref mapped_type;
+ however, \p func must guarantee that during changing no any other modifications
+ could be made on this item by concurrent threads.
+
+ Returns std::pair<bool, bool> where \p first is \p true if operation is successful,
+ i.e. the node has been inserted or updated,
+ \p second is \p true if new item has been added or \p false if the item with \p key
+ already exists.
+
+ @warning See \ref cds_intrusive_item_creating "insert item troubleshooting"
+ */
+ template <typename K, typename Func>
+ std::pair<bool, bool> update( K const& key, Func func, bool bAllowInsert = true )
+ {
+ scoped_node_ptr pNode( cxx_leaf_node_allocator().New( key ));
+ std::pair<bool, bool> res = base_class::update( *pNode,
+ [&func](bool bNew, leaf_node& item, leaf_node const& ){ func( bNew, item.m_Value ); },
+ bAllowInsert
+ );
+ if ( res.first && res.second )
+ pNode.release();
+ return res;
+ }
+ //@cond
+ template <typename K, typename Func>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
+ std::pair<bool, bool> ensure( K const& key, Func func )
+ {
+ return update( key, func, true );
+ }
+ //@endcond
+
+ /// 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 )
+ {
+ CDS_UNUSED( 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
+
+ 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) { 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 )
+ {
+ CDS_UNUSED( pred );
+ return base_class::erase_with( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::key_accessor >(),
+ [&f]( leaf_node& node) { f( node.m_Value ); } );
+ }
+
+ /// Extracts an item with minimal key from the map
+ /**
+ If the map is not empty, the function returns an guarded pointer to minimum value.
+ If the map is empty, the function returns an empty \p guarded_ptr.
+
+ @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 prevents deallocation of returned item,
+ see \p cds::gc::guarded_ptr for explanation.
+ @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
+ */
+ guarded_ptr extract_min()
+ {
+ return guarded_ptr( base_class::extract_min_());
+ }
+
+ /// Extracts an item with maximal key from the map
+ /**
+ If the map is not empty, the function returns a guarded pointer to maximal value.
+ If the map is empty, the function returns an empty \p guarded_ptr.
+
+ @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 prevents deallocation of returned item,
+ see \p cds::gc::guarded_ptr for explanation.
+ @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
+ */
+ guarded_ptr extract_max()
+ {
+ return guarded_ptr( base_class::extract_max_());
+ }
+
+ /// 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 a guarded pointer to an item found.
+ If the item is not found the function returns an empty \p guarded_ptr.
+
+ The guarded pointer prevents deallocation of returned item,
+ see \p 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>
+ guarded_ptr extract( Q const& key )
+ {
+ return guarded_ptr( base_class::extract_( key ));
+ }
+
+ /// Extracts an item from the map using \p pred for searching
+ /**
+ The function is an analog of \ref cds_nonintrusive_EllenBinTreeMap_extract "extract(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>
+ guarded_ptr extract_with( Q const& key, Less pred )
+ {
+ CDS_UNUSED( pred );
+ return guarded_ptr( base_class::extract_with_( 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.
+
+ 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& ) { 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 )
+ {
+ CDS_UNUSED( pred );
+ return base_class::find_with( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::key_accessor >(),
+ [&f](leaf_node& item, K const& ) { f( item.m_Value );});
+ }
+
+ /// Checks whether the map contains \p key
+ /**
+ 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 contains( K const& key )
+ {
+ return base_class::contains( key );
+ }
+ //@cond
+ template <typename K>
+ CDS_DEPRECATED("deprecated, use contains()")
+ bool find( K const& key )
+ {
+ return contains( key );
+ }
+ //@endcond
+
+ /// Checks whether the map contains \p key using \p pred predicate for searching
+ /**
+ The function is similar to <tt>contains( key )</tt> 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 set.
+ */
+ template <typename K, typename Less>
+ bool contains( K const& key, Less pred )
+ {
+ CDS_UNUSED( pred );
+ return base_class::contains( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::key_accessor >());
+ }
+ //@cond
+ template <typename K, typename Less>
+ CDS_DEPRECATED("deprecated, use contains()")
+ bool find_with( K const& key, Less pred )
+ {
+ return contains( key, pred );
+ }
+ //@endcond
+
+ /// 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 as a guarded pointer.
+ If \p key is not foudn the function returns an empty \p guarded_ptr.
+
+ The guarded pointer prevents deallocation of returned item,
+ see \p 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>
+ guarded_ptr get( Q const& key )
+ {
+ return guarded_ptr( base_class::get_( 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(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>
+ guarded_ptr get_with( Q const& key, Less pred )
+ {
+ CDS_UNUSED( pred );
+ return guarded_ptr( base_class::get_with_( key,
+ cds::details::predicate_wrapper< leaf_node, Less, typename maker::key_accessor >()));
+ }
+
+ /// Clears the map (not atomic)
+ 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 set
+ /**
+ Only leaf nodes containing user data are counted.
+
+ The value returned depends on item counter type provided by \p Traits template parameter.
+ If it is \p atomicity::empty_item_counter this function always returns 0.
+
+ The function is not suitable for checking the tree emptiness, use \p empty()
+ member function for this purpose.
+ */
+ 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 CDSLIB_CONTAINER_IMPL_ELLEN_BINTREE_MAP_H