boost/intrusive/treap_algorithms.hpp
///////////////////////////////////////////////////////////////////////////// // // (C) Copyright Ion Gaztanaga 2006-2013. // // Distributed under the Boost Software License, Version 1.0. // (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) // // See http://www.boost.org/libs/intrusive for documentation. // ///////////////////////////////////////////////////////////////////////////// #ifndef BOOST_INTRUSIVE_TREAP_ALGORITHMS_HPP #define BOOST_INTRUSIVE_TREAP_ALGORITHMS_HPP #include <boost/intrusive/detail/config_begin.hpp> #include <boost/intrusive/intrusive_fwd.hpp> #include <cstddef> #include <boost/intrusive/detail/assert.hpp> #include <boost/intrusive/pointer_traits.hpp> #include <boost/intrusive/detail/utilities.hpp> #include <boost/intrusive/bstree_algorithms.hpp> #include <algorithm> namespace boost { namespace intrusive { //! treap_algorithms provides basic algorithms to manipulate //! nodes forming a treap. //! //! (1) the header node is maintained with links not only to the root //! but also to the leftmost node of the tree, to enable constant time //! begin(), and to the rightmost node of the tree, to enable linear time //! performance when used with the generic set algorithms (set_union, //! etc.); //! //! (2) when a node being deleted has two children its successor node is //! relinked into its place, rather than copied, so that the only //! pointers invalidated are those referring to the deleted node. //! //! treap_algorithms is configured with a NodeTraits class, which encapsulates the //! information about the node to be manipulated. NodeTraits must support the //! following interface: //! //! <b>Typedefs</b>: //! //! <tt>node</tt>: The type of the node that forms the treap //! //! <tt>node_ptr</tt>: A pointer to a node //! //! <tt>const_node_ptr</tt>: A pointer to a const node //! //! <b>Static functions</b>: //! //! <tt>static node_ptr get_parent(const_node_ptr n);</tt> //! //! <tt>static void set_parent(node_ptr n, node_ptr parent);</tt> //! //! <tt>static node_ptr get_left(const_node_ptr n);</tt> //! //! <tt>static void set_left(node_ptr n, node_ptr left);</tt> //! //! <tt>static node_ptr get_right(const_node_ptr n);</tt> //! //! <tt>static void set_right(node_ptr n, node_ptr right);</tt> template<class NodeTraits> class treap_algorithms #ifndef BOOST_INTRUSIVE_DOXYGEN_INVOKED : public bstree_algorithms<NodeTraits> #endif { public: typedef NodeTraits node_traits; typedef typename NodeTraits::node node; typedef typename NodeTraits::node_ptr node_ptr; typedef typename NodeTraits::const_node_ptr const_node_ptr; /// @cond private: typedef bstree_algorithms<NodeTraits> bstree_algo; class rerotate_on_destroy { rerotate_on_destroy& operator=(const rerotate_on_destroy&); public: rerotate_on_destroy(const node_ptr & header, const node_ptr & p, std::size_t &n) : header_(header), p_(p), n_(n), remove_it_(true) {} ~rerotate_on_destroy() { if(remove_it_){ rotate_up_n(header_, p_, n_); } } void release() { remove_it_ = false; } const node_ptr header_; const node_ptr p_; std::size_t &n_; bool remove_it_; }; static void rotate_up_n(const node_ptr header, const node_ptr p, std::size_t n) { node_ptr p_parent(NodeTraits::get_parent(p)); node_ptr p_grandparent(NodeTraits::get_parent(p_parent)); while(n--){ if(p == NodeTraits::get_left(p_parent)){ //p is left child bstree_algo::rotate_right(p_parent, p, p_grandparent, header); } else{ //p is right child bstree_algo::rotate_left(p_parent, p, p_grandparent, header); } p_parent = p_grandparent; p_grandparent = NodeTraits::get_parent(p_parent); } } /// @endcond public: //! This type is the information that will be //! filled by insert_unique_check struct insert_commit_data /// @cond : public bstree_algo::insert_commit_data /// @endcond { /// @cond std::size_t rotations; /// @endcond }; #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED //! @copydoc ::boost::intrusive::bstree_algorithms::get_header(const const_node_ptr&) static node_ptr get_header(const const_node_ptr & n); //! @copydoc ::boost::intrusive::bstree_algorithms::begin_node static node_ptr begin_node(const const_node_ptr & header); //! @copydoc ::boost::intrusive::bstree_algorithms::end_node static node_ptr end_node(const const_node_ptr & header); //! @copydoc ::boost::intrusive::bstree_algorithms::swap_tree static void swap_tree(const node_ptr & header1, const node_ptr & header2); //! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(const node_ptr&,const node_ptr&) static void swap_nodes(const node_ptr & node1, const node_ptr & node2); //! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(const node_ptr&,const node_ptr&,const node_ptr&,const node_ptr&) static void swap_nodes(const node_ptr & node1, const node_ptr & header1, const node_ptr & node2, const node_ptr & header2); //! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(const node_ptr&,const node_ptr&) static void replace_node(const node_ptr & node_to_be_replaced, const node_ptr & new_node); //! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(const node_ptr&,const node_ptr&,const node_ptr&) static void replace_node(const node_ptr & node_to_be_replaced, const node_ptr & header, const node_ptr & new_node); #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED //! @copydoc ::boost::intrusive::bstree_algorithms::unlink(const node_ptr&) template<class NodePtrPriorityCompare> static void unlink(const node_ptr & node, NodePtrPriorityCompare pcomp) { node_ptr x = NodeTraits::get_parent(node); if(x){ while(!bstree_algo::is_header(x)) x = NodeTraits::get_parent(x); erase(x, node, pcomp); } } #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED //! @copydoc ::boost::intrusive::bstree_algorithms::unlink_leftmost_without_rebalance static node_ptr unlink_leftmost_without_rebalance(const node_ptr & header); //! @copydoc ::boost::intrusive::bstree_algorithms::unique(const const_node_ptr&) static bool unique(const const_node_ptr & node); //! @copydoc ::boost::intrusive::bstree_algorithms::size(const const_node_ptr&) static std::size_t size(const const_node_ptr & header); //! @copydoc ::boost::intrusive::bstree_algorithms::next_node(const node_ptr&) static node_ptr next_node(const node_ptr & node); //! @copydoc ::boost::intrusive::bstree_algorithms::prev_node(const node_ptr&) static node_ptr prev_node(const node_ptr & node); //! @copydoc ::boost::intrusive::bstree_algorithms::init(const node_ptr&) static void init(const node_ptr & node); //! @copydoc ::boost::intrusive::bstree_algorithms::init_header(const node_ptr&) static void init_header(const node_ptr & header); #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED //! @copydoc ::boost::intrusive::bstree_algorithms::erase(const node_ptr&,const node_ptr&) template<class NodePtrPriorityCompare> static node_ptr erase(const node_ptr & header, const node_ptr & z, NodePtrPriorityCompare pcomp) { rebalance_for_erasure(header, z, pcomp); bstree_algo::erase(header, z); return z; } #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED //! @copydoc ::boost::intrusive::bstree_algorithms::clone(const const_node_ptr&,const node_ptr&,Cloner,Disposer) template <class Cloner, class Disposer> static void clone (const const_node_ptr & source_header, const node_ptr & target_header, Cloner cloner, Disposer disposer); //! @copydoc ::boost::intrusive::bstree_algorithms::clear_and_dispose(const node_ptr&,Disposer) template<class Disposer> static void clear_and_dispose(const node_ptr & header, Disposer disposer); //! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) template<class KeyType, class KeyNodePtrCompare> static node_ptr lower_bound (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp); //! @copydoc ::boost::intrusive::bstree_algorithms::upper_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) template<class KeyType, class KeyNodePtrCompare> static node_ptr upper_bound (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp); //! @copydoc ::boost::intrusive::bstree_algorithms::find(const const_node_ptr&, const KeyType&,KeyNodePtrCompare) template<class KeyType, class KeyNodePtrCompare> static node_ptr find (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp); //! @copydoc ::boost::intrusive::bstree_algorithms::equal_range(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) template<class KeyType, class KeyNodePtrCompare> static std::pair<node_ptr, node_ptr> equal_range (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp); //! @copydoc ::boost::intrusive::bstree_algorithms::bounded_range(const const_node_ptr&,const KeyType&,const KeyType&,KeyNodePtrCompare,bool,bool) template<class KeyType, class KeyNodePtrCompare> static std::pair<node_ptr, node_ptr> bounded_range (const const_node_ptr & header, const KeyType &lower_key, const KeyType &upper_key, KeyNodePtrCompare comp , bool left_closed, bool right_closed); //! @copydoc ::boost::intrusive::bstree_algorithms::count(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) template<class KeyType, class KeyNodePtrCompare> static std::size_t count(const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp); #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED //! <b>Requires</b>: "h" must be the header node of a tree. //! NodePtrCompare is a function object that induces a strict weak //! ordering compatible with the strict weak ordering used to create the //! the tree. NodePtrCompare compares two node_ptrs. //! NodePtrPriorityCompare is a priority function object that induces a strict weak //! ordering compatible with the one used to create the //! the tree. NodePtrPriorityCompare compares two node_ptrs. //! //! <b>Effects</b>: Inserts new_node into the tree before the upper bound //! according to "comp" and rotates the tree according to "pcomp". //! //! <b>Complexity</b>: Average complexity for insert element is at //! most logarithmic. //! //! <b>Throws</b>: If "comp" throw or "pcomp" throw. template<class NodePtrCompare, class NodePtrPriorityCompare> static node_ptr insert_equal_upper_bound (const node_ptr & h, const node_ptr & new_node, NodePtrCompare comp, NodePtrPriorityCompare pcomp) { insert_commit_data commit_data; bstree_algo::insert_equal_upper_bound_check(h, new_node, comp, commit_data); rebalance_check_and_commit(h, new_node, pcomp, commit_data); return new_node; } //! <b>Requires</b>: "h" must be the header node of a tree. //! NodePtrCompare is a function object that induces a strict weak //! ordering compatible with the strict weak ordering used to create the //! the tree. NodePtrCompare compares two node_ptrs. //! NodePtrPriorityCompare is a priority function object that induces a strict weak //! ordering compatible with the one used to create the //! the tree. NodePtrPriorityCompare compares two node_ptrs. //! //! <b>Effects</b>: Inserts new_node into the tree before the upper bound //! according to "comp" and rotates the tree according to "pcomp". //! //! <b>Complexity</b>: Average complexity for insert element is at //! most logarithmic. //! //! <b>Throws</b>: If "comp" throws. template<class NodePtrCompare, class NodePtrPriorityCompare> static node_ptr insert_equal_lower_bound (const node_ptr & h, const node_ptr & new_node, NodePtrCompare comp, NodePtrPriorityCompare pcomp) { insert_commit_data commit_data; bstree_algo::insert_equal_lower_bound_check(h, new_node, comp, commit_data); rebalance_check_and_commit(h, new_node, pcomp, commit_data); return new_node; } //! <b>Requires</b>: "header" must be the header node of a tree. //! NodePtrCompare is a function object that induces a strict weak //! ordering compatible with the strict weak ordering used to create the //! the tree. NodePtrCompare compares two node_ptrs. "hint" is node from //! the "header"'s tree. //! NodePtrPriorityCompare is a priority function object that induces a strict weak //! ordering compatible with the one used to create the //! the tree. NodePtrPriorityCompare compares two node_ptrs. //! //! <b>Effects</b>: Inserts new_node into the tree, using "hint" as a hint to //! where it will be inserted. If "hint" is the upper_bound //! the insertion takes constant time (two comparisons in the worst case). //! Rotates the tree according to "pcomp". //! //! <b>Complexity</b>: Logarithmic in general, but it is amortized //! constant time if new_node is inserted immediately before "hint". //! //! <b>Throws</b>: If "comp" throw or "pcomp" throw. template<class NodePtrCompare, class NodePtrPriorityCompare> static node_ptr insert_equal (const node_ptr & h, const node_ptr & hint, const node_ptr & new_node, NodePtrCompare comp, NodePtrPriorityCompare pcomp) { insert_commit_data commit_data; bstree_algo::insert_equal_check(h, hint, new_node, comp, commit_data); rebalance_check_and_commit(h, new_node, pcomp, commit_data); return new_node; } //! <b>Requires</b>: "header" must be the header node of a tree. //! "pos" must be a valid node of the tree (including header end) node. //! "pos" must be a node pointing to the successor to "new_node" //! once inserted according to the order of already inserted nodes. This function does not //! check "pos" and this precondition must be guaranteed by the caller. //! NodePtrPriorityCompare is a priority function object that induces a strict weak //! ordering compatible with the one used to create the //! the tree. NodePtrPriorityCompare compares two node_ptrs. //! //! <b>Effects</b>: Inserts new_node into the tree before "pos" //! and rotates the tree according to "pcomp". //! //! <b>Complexity</b>: Constant-time. //! //! <b>Throws</b>: If "pcomp" throws, strong guarantee. //! //! <b>Note</b>: If "pos" is not the successor of the newly inserted "new_node" //! tree invariants might be broken. template<class NodePtrPriorityCompare> static node_ptr insert_before (const node_ptr & header, const node_ptr & pos, const node_ptr & new_node, NodePtrPriorityCompare pcomp) { insert_commit_data commit_data; bstree_algo::insert_before_check(header, pos, commit_data); rebalance_check_and_commit(header, new_node, pcomp, commit_data); return new_node; } //! <b>Requires</b>: "header" must be the header node of a tree. //! "new_node" must be, according to the used ordering no less than the //! greatest inserted key. //! NodePtrPriorityCompare is a priority function object that induces a strict weak //! ordering compatible with the one used to create the //! the tree. NodePtrPriorityCompare compares two node_ptrs. //! //! <b>Effects</b>: Inserts x into the tree in the last position //! and rotates the tree according to "pcomp". //! //! <b>Complexity</b>: Constant-time. //! //! <b>Throws</b>: If "pcomp" throws, strong guarantee. //! //! <b>Note</b>: If "new_node" is less than the greatest inserted key //! tree invariants are broken. This function is slightly faster than //! using "insert_before". template<class NodePtrPriorityCompare> static void push_back(const node_ptr & header, const node_ptr & new_node, NodePtrPriorityCompare pcomp) { insert_commit_data commit_data; bstree_algo::push_back_check(header, commit_data); rebalance_check_and_commit(header, new_node, pcomp, commit_data); } //! <b>Requires</b>: "header" must be the header node of a tree. //! "new_node" must be, according to the used ordering, no greater than the //! lowest inserted key. //! NodePtrPriorityCompare is a priority function object that induces a strict weak //! ordering compatible with the one used to create the //! the tree. NodePtrPriorityCompare compares two node_ptrs. //! //! <b>Effects</b>: Inserts x into the tree in the first position //! and rotates the tree according to "pcomp". //! //! <b>Complexity</b>: Constant-time. //! //! <b>Throws</b>: If "pcomp" throws, strong guarantee. //! //! <b>Note</b>: If "new_node" is greater than the lowest inserted key //! tree invariants are broken. This function is slightly faster than //! using "insert_before". template<class NodePtrPriorityCompare> static void push_front(const node_ptr & header, const node_ptr & new_node, NodePtrPriorityCompare pcomp) { insert_commit_data commit_data; bstree_algo::push_front_check(header, commit_data); rebalance_check_and_commit(header, new_node, pcomp, commit_data); } //! <b>Requires</b>: "header" must be the header node of a tree. //! KeyNodePtrCompare is a function object that induces a strict weak //! ordering compatible with the strict weak ordering used to create the //! the tree. NodePtrCompare compares KeyType with a node_ptr. //! //! <b>Effects</b>: Checks if there is an equivalent node to "key" in the //! tree according to "comp" and obtains the needed information to realize //! a constant-time node insertion if there is no equivalent node. //! //! <b>Returns</b>: If there is an equivalent value //! returns a pair containing a node_ptr to the already present node //! and false. If there is not equivalent key can be inserted returns true //! in the returned pair's boolean and fills "commit_data" that is meant to //! be used with the "insert_commit" function to achieve a constant-time //! insertion function. //! //! <b>Complexity</b>: Average complexity is at most logarithmic. //! //! <b>Throws</b>: If "comp" throws. //! //! <b>Notes</b>: This function is used to improve performance when constructing //! a node is expensive and the user does not want to have two equivalent nodes //! in the tree: if there is an equivalent value //! the constructed object must be discarded. Many times, the part of the //! node that is used to impose the order is much cheaper to construct //! than the node and this function offers the possibility to use that part //! to check if the insertion will be successful. //! //! If the check is successful, the user can construct the node and use //! "insert_commit" to insert the node in constant-time. This gives a total //! logarithmic complexity to the insertion: check(O(log(N)) + commit(O(1)). //! //! "commit_data" remains valid for a subsequent "insert_unique_commit" only //! if no more objects are inserted or erased from the set. template<class KeyType, class KeyNodePtrCompare, class KeyNodePtrPrioCompare> static std::pair<node_ptr, bool> insert_unique_check (const const_node_ptr & header, const KeyType &key ,KeyNodePtrCompare comp, KeyNodePtrPrioCompare pcomp ,insert_commit_data &commit_data) { std::pair<node_ptr, bool> ret = bstree_algo::insert_unique_check(header, key, comp, commit_data); if(ret.second) rebalance_after_insertion_check(header, commit_data.node, key, pcomp, commit_data.rotations); return ret; } //! <b>Requires</b>: "header" must be the header node of a tree. //! KeyNodePtrCompare is a function object that induces a strict weak //! ordering compatible with the strict weak ordering used to create the //! the tree. NodePtrCompare compares KeyType with a node_ptr. //! "hint" is node from the "header"'s tree. //! //! <b>Effects</b>: Checks if there is an equivalent node to "key" in the //! tree according to "comp" using "hint" as a hint to where it should be //! inserted and obtains the needed information to realize //! a constant-time node insertion if there is no equivalent node. //! If "hint" is the upper_bound the function has constant time //! complexity (two comparisons in the worst case). //! //! <b>Returns</b>: If there is an equivalent value //! returns a pair containing a node_ptr to the already present node //! and false. If there is not equivalent key can be inserted returns true //! in the returned pair's boolean and fills "commit_data" that is meant to //! be used with the "insert_commit" function to achieve a constant-time //! insertion function. //! //! <b>Complexity</b>: Average complexity is at most logarithmic, but it is //! amortized constant time if new_node should be inserted immediately before "hint". //! //! <b>Throws</b>: If "comp" throws. //! //! <b>Notes</b>: This function is used to improve performance when constructing //! a node is expensive and the user does not want to have two equivalent nodes //! in the tree: if there is an equivalent value //! the constructed object must be discarded. Many times, the part of the //! node that is used to impose the order is much cheaper to construct //! than the node and this function offers the possibility to use that part //! to check if the insertion will be successful. //! //! If the check is successful, the user can construct the node and use //! "insert_commit" to insert the node in constant-time. This gives a total //! logarithmic complexity to the insertion: check(O(log(N)) + commit(O(1)). //! //! "commit_data" remains valid for a subsequent "insert_unique_commit" only //! if no more objects are inserted or erased from the set. template<class KeyType, class KeyNodePtrCompare, class KeyNodePtrPrioCompare> static std::pair<node_ptr, bool> insert_unique_check (const const_node_ptr & header, const node_ptr & hint, const KeyType &key ,KeyNodePtrCompare comp, KeyNodePtrPrioCompare pcomp, insert_commit_data &commit_data) { std::pair<node_ptr, bool> ret = bstree_algo::insert_unique_check(header, hint, key, comp, commit_data); if(ret.second) rebalance_after_insertion_check(header, commit_data.node, key, pcomp, commit_data.rotations); return ret; } //! <b>Requires</b>: "header" must be the header node of a tree. //! "commit_data" must have been obtained from a previous call to //! "insert_unique_check". No objects should have been inserted or erased //! from the set between the "insert_unique_check" that filled "commit_data" //! and the call to "insert_commit". //! //! //! <b>Effects</b>: Inserts new_node in the set using the information obtained //! from the "commit_data" that a previous "insert_check" filled. //! //! <b>Complexity</b>: Constant time. //! //! <b>Throws</b>: Nothing. //! //! <b>Notes</b>: This function has only sense if a "insert_unique_check" has been //! previously executed to fill "commit_data". No value should be inserted or //! erased between the "insert_check" and "insert_commit" calls. static void insert_unique_commit (const node_ptr & header, const node_ptr & new_node, const insert_commit_data &commit_data) { bstree_algo::insert_unique_commit(header, new_node, commit_data); rotate_up_n(header, new_node, commit_data.rotations); } #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED //! @copydoc ::boost::intrusive::bstree_algorithms::is_header static bool is_header(const const_node_ptr & p); #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED /// @cond private: template<class NodePtrPriorityCompare> static void rebalance_for_erasure(const node_ptr & header, const node_ptr & z, NodePtrPriorityCompare pcomp) { std::size_t n = 0; rerotate_on_destroy rb(header, z, n); node_ptr z_left = NodeTraits::get_left(z); node_ptr z_right = NodeTraits::get_right(z); while(z_left || z_right){ const node_ptr z_parent(NodeTraits::get_parent(z)); if(!z_right || (z_left && pcomp(z_left, z_right))){ bstree_algo::rotate_right(z, z_left, z_parent, header); } else{ bstree_algo::rotate_left(z, z_right, z_parent, header); } ++n; z_left = NodeTraits::get_left(z); z_right = NodeTraits::get_right(z); } rb.release(); } template<class NodePtrPriorityCompare> static void rebalance_check_and_commit (const node_ptr & h, const node_ptr & new_node, NodePtrPriorityCompare pcomp, insert_commit_data &commit_data) { rebalance_after_insertion_check(h, commit_data.node, new_node, pcomp, commit_data.rotations); //No-throw bstree_algo::insert_unique_commit(h, new_node, commit_data); rotate_up_n(h, new_node, commit_data.rotations); } template<class Key, class KeyNodePriorityCompare> static void rebalance_after_insertion_check (const const_node_ptr &header, const const_node_ptr & up, const Key &k , KeyNodePriorityCompare pcomp, std::size_t &num_rotations) { const_node_ptr upnode(up); //First check rotations since pcomp can throw num_rotations = 0; std::size_t n = 0; while(upnode != header && pcomp(k, upnode)){ ++n; upnode = NodeTraits::get_parent(upnode); } num_rotations = n; } template<class NodePtrPriorityCompare> static bool check_invariant(const const_node_ptr & header, NodePtrPriorityCompare pcomp) { node_ptr beg = begin_node(header); node_ptr end = end_node(header); while(beg != end){ node_ptr p = NodeTraits::get_parent(beg); if(p != header){ if(pcomp(beg, p)) return false; } beg = next_node(beg); } return true; } /// @endcond }; /// @cond template<class NodeTraits> struct get_algo<TreapAlgorithms, NodeTraits> { typedef treap_algorithms<NodeTraits> type; }; /// @endcond } //namespace intrusive } //namespace boost #include <boost/intrusive/detail/config_end.hpp> #endif //BOOST_INTRUSIVE_TREAP_ALGORITHMS_HPP