boost/intrusive/splaytree_algorithms.hpp
///////////////////////////////////////////////////////////////////////////// // // (C) Copyright Ion Gaztanaga 2007-2014 // // 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. // ///////////////////////////////////////////////////////////////////////////// // The implementation of splay trees is based on the article and code published // in C++ Users Journal "Implementing Splay Trees in C++" (September 1, 2005). // // The splay code has been modified and (supposedly) improved by Ion Gaztanaga. // // Here is the copyright notice of the original file containing the splay code: // // splay_tree.h -- implementation of a STL compatible splay tree. // // Copyright (c) 2004 Ralf Mattethat // // Permission to copy, use, modify, sell and distribute this software // is granted provided this copyright notice appears in all copies. // This software is provided "as is" without express or implied // warranty, and with no claim as to its suitability for any purpose. // ///////////////////////////////////////////////////////////////////////////// #ifndef BOOST_INTRUSIVE_SPLAYTREE_ALGORITHMS_HPP #define BOOST_INTRUSIVE_SPLAYTREE_ALGORITHMS_HPP #include <boost/intrusive/detail/config_begin.hpp> #include <boost/intrusive/intrusive_fwd.hpp> #include <boost/intrusive/detail/assert.hpp> #include <boost/intrusive/detail/algo_type.hpp> #include <boost/intrusive/detail/uncast.hpp> #include <boost/intrusive/bstree_algorithms.hpp> #include <cstddef> #if defined(BOOST_HAS_PRAGMA_ONCE) # pragma once #endif namespace boost { namespace intrusive { /// @cond namespace detail { template<class NodeTraits> struct splaydown_assemble_and_fix_header { typedef typename NodeTraits::node_ptr node_ptr; splaydown_assemble_and_fix_header(const node_ptr & t, const node_ptr & header, const node_ptr &leftmost, const node_ptr &rightmost) : t_(t) , null_node_(header) , l_(null_node_) , r_(null_node_) , leftmost_(leftmost) , rightmost_(rightmost) {} ~splaydown_assemble_and_fix_header() { this->assemble(); //Now recover the original header except for the //splayed root node. //"t_" is the current root and "null_node_" is the header node NodeTraits::set_parent(null_node_, t_); NodeTraits::set_parent(t_, null_node_); //Recover leftmost/rightmost pointers NodeTraits::set_left (null_node_, leftmost_); NodeTraits::set_right(null_node_, rightmost_); } private: void assemble() { //procedure assemble; // left(r), right(l) := right(t), left(t); // left(t), right(t) := right(null), left(null); //end assemble; { // left(r), right(l) := right(t), left(t); node_ptr const old_t_left = NodeTraits::get_left(t_); node_ptr const old_t_right = NodeTraits::get_right(t_); NodeTraits::set_right(l_, old_t_left); NodeTraits::set_left (r_, old_t_right); if(old_t_left){ NodeTraits::set_parent(old_t_left, l_); } if(old_t_right){ NodeTraits::set_parent(old_t_right, r_); } } { // left(t), right(t) := right(null), left(null); node_ptr const null_right = NodeTraits::get_right(null_node_); node_ptr const null_left = NodeTraits::get_left(null_node_); NodeTraits::set_left (t_, null_right); NodeTraits::set_right(t_, null_left); if(null_right){ NodeTraits::set_parent(null_right, t_); } if(null_left){ NodeTraits::set_parent(null_left, t_); } } } public: node_ptr t_, null_node_, l_, r_, leftmost_, rightmost_; }; } //namespace detail { /// @endcond //! A splay tree is an implementation of a binary search tree. The tree is //! self balancing using the splay algorithm as described in //! //! "Self-Adjusting Binary Search Trees //! by Daniel Dominic Sleator and Robert Endre Tarjan //! AT&T Bell Laboratories, Murray Hill, NJ //! Journal of the ACM, Vol 32, no 3, July 1985, pp 652-686 //! //! splaytree_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 binary search tree //! //! <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 splaytree_algorithms #ifndef BOOST_INTRUSIVE_DOXYGEN_INVOKED : public bstree_algorithms<NodeTraits> #endif { /// @cond private: typedef bstree_algorithms<NodeTraits> bstree_algo; /// @endcond public: typedef typename NodeTraits::node node; typedef NodeTraits node_traits; typedef typename NodeTraits::node_ptr node_ptr; typedef typename NodeTraits::const_node_ptr const_node_ptr; //! This type is the information that will be //! filled by insert_unique_check typedef typename bstree_algo::insert_commit_data insert_commit_data; public: #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); //! @copydoc ::boost::intrusive::bstree_algorithms::unlink(const node_ptr&) static void unlink(const node_ptr & node); //! @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&) //! Additional notes: the previous node of z is splayed to speed up range deletions. static void erase(const node_ptr & header, const node_ptr & z) { //posibility 1 if(NodeTraits::get_left(z)){ splay_up(bstree_algo::prev_node(z), header); } //possibility 2 //if(NodeTraits::get_left(z)){ // node_ptr l = NodeTraits::get_left(z); // splay_up(l, header); //} //if(NodeTraits::get_left(z)){ // node_ptr l = bstree_algo::prev_node(z); // splay_up_impl(l, z); //} //possibility 4 //splay_up(z, header); bstree_algo::erase(header, 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); #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED //! @copydoc ::boost::intrusive::bstree_algorithms::count(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) //! Additional notes: an element with key `key` is splayed. template<class KeyType, class KeyNodePtrCompare> static std::size_t count (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp) { std::pair<node_ptr, node_ptr> ret = equal_range(header, key, comp); std::size_t n = 0; while(ret.first != ret.second){ ++n; ret.first = next_node(ret.first); } return n; } //! @copydoc ::boost::intrusive::bstree_algorithms::count(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) //! Additional note: no splaying is performed template<class KeyType, class KeyNodePtrCompare> static std::size_t count (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp) { return bstree_algo::count(header, key, comp); } //! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) //! Additional notes: the first node of the range is splayed. template<class KeyType, class KeyNodePtrCompare> static node_ptr lower_bound (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp) { splay_down(detail::uncast(header), key, comp); node_ptr y = bstree_algo::lower_bound(header, key, comp); //splay_up(y, detail::uncast(header)); return y; } //! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) //! Additional note: no splaying is performed template<class KeyType, class KeyNodePtrCompare> static node_ptr lower_bound (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp) { return bstree_algo::lower_bound(header, key, comp); } //! @copydoc ::boost::intrusive::bstree_algorithms::upper_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) //! Additional notes: the first node of the range is splayed. template<class KeyType, class KeyNodePtrCompare> static node_ptr upper_bound (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp) { splay_down(detail::uncast(header), key, comp); node_ptr y = bstree_algo::upper_bound(header, key, comp); //splay_up(y, detail::uncast(header)); return y; } //! @copydoc ::boost::intrusive::bstree_algorithms::upper_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) //! Additional note: no splaying is performed template<class KeyType, class KeyNodePtrCompare> static node_ptr upper_bound (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp) { return bstree_algo::upper_bound(header, key, comp); } //! @copydoc ::boost::intrusive::bstree_algorithms::find(const const_node_ptr&, const KeyType&,KeyNodePtrCompare) //! Additional notes: the found node of the lower bound is splayed. template<class KeyType, class KeyNodePtrCompare> static node_ptr find (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp) { splay_down(detail::uncast(header), key, comp); return bstree_algo::find(header, key, comp); } //! @copydoc ::boost::intrusive::bstree_algorithms::find(const const_node_ptr&, const KeyType&,KeyNodePtrCompare) //! Additional note: no splaying is performed template<class KeyType, class KeyNodePtrCompare> static node_ptr find (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp) { return bstree_algo::find(header, key, comp); } //! @copydoc ::boost::intrusive::bstree_algorithms::equal_range(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) //! Additional notes: the first node of the range is splayed. template<class KeyType, class KeyNodePtrCompare> static std::pair<node_ptr, node_ptr> equal_range (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp) { splay_down(detail::uncast(header), key, comp); std::pair<node_ptr, node_ptr> ret = bstree_algo::equal_range(header, key, comp); //splay_up(ret.first, detail::uncast(header)); return ret; } //! @copydoc ::boost::intrusive::bstree_algorithms::equal_range(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) //! Additional note: no splaying is performed template<class KeyType, class KeyNodePtrCompare> static std::pair<node_ptr, node_ptr> equal_range (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp) { return bstree_algo::equal_range(header, key, comp); } //! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound_range(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) //! Additional notes: the first node of the range is splayed. template<class KeyType, class KeyNodePtrCompare> static std::pair<node_ptr, node_ptr> lower_bound_range (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp) { splay_down(detail::uncast(header), key, comp); std::pair<node_ptr, node_ptr> ret = bstree_algo::lower_bound_range(header, key, comp); //splay_up(ret.first, detail::uncast(header)); return ret; } //! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound_range(const const_node_ptr&,const KeyType&,KeyNodePtrCompare) //! Additional note: no splaying is performed template<class KeyType, class KeyNodePtrCompare> static std::pair<node_ptr, node_ptr> lower_bound_range (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp) { return bstree_algo::lower_bound_range(header, key, comp); } //! @copydoc ::boost::intrusive::bstree_algorithms::bounded_range(const const_node_ptr&,const KeyType&,const KeyType&,KeyNodePtrCompare,bool,bool) //! Additional notes: the first node of the range is splayed. template<class KeyType, class KeyNodePtrCompare> static std::pair<node_ptr, node_ptr> bounded_range (const node_ptr & header, const KeyType &lower_key, const KeyType &upper_key, KeyNodePtrCompare comp , bool left_closed, bool right_closed) { splay_down(detail::uncast(header), lower_key, comp); std::pair<node_ptr, node_ptr> ret = bstree_algo::bounded_range(header, lower_key, upper_key, comp, left_closed, right_closed); //splay_up(ret.first, detail::uncast(header)); return ret; } //! @copydoc ::boost::intrusive::bstree_algorithms::bounded_range(const const_node_ptr&,const KeyType&,const KeyType&,KeyNodePtrCompare,bool,bool) //! Additional note: no splaying is performed 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) { return bstree_algo::bounded_range(header, lower_key, upper_key, comp, left_closed, right_closed); } //! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal_upper_bound(const node_ptr&,const node_ptr&,NodePtrCompare) //! Additional note: the inserted node is splayed template<class NodePtrCompare> static node_ptr insert_equal_upper_bound (const node_ptr & header, const node_ptr & new_node, NodePtrCompare comp) { splay_down(header, new_node, comp); return bstree_algo::insert_equal_upper_bound(header, new_node, comp); } //! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal_lower_bound(const node_ptr&,const node_ptr&,NodePtrCompare) //! Additional note: the inserted node is splayed template<class NodePtrCompare> static node_ptr insert_equal_lower_bound (const node_ptr & header, const node_ptr & new_node, NodePtrCompare comp) { splay_down(header, new_node, comp); return bstree_algo::insert_equal_lower_bound(header, new_node, comp); } //! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal(const node_ptr&,const node_ptr&,const node_ptr&,NodePtrCompare) //! Additional note: the inserted node is splayed template<class NodePtrCompare> static node_ptr insert_equal (const node_ptr & header, const node_ptr & hint, const node_ptr & new_node, NodePtrCompare comp) { splay_down(header, new_node, comp); return bstree_algo::insert_equal(header, hint, new_node, comp); } //! @copydoc ::boost::intrusive::bstree_algorithms::insert_before(const node_ptr&,const node_ptr&,const node_ptr&) //! Additional note: the inserted node is splayed static node_ptr insert_before (const node_ptr & header, const node_ptr & pos, const node_ptr & new_node) { bstree_algo::insert_before(header, pos, new_node); splay_up(new_node, header); return new_node; } //! @copydoc ::boost::intrusive::bstree_algorithms::push_back(const node_ptr&,const node_ptr&) //! Additional note: the inserted node is splayed static void push_back(const node_ptr & header, const node_ptr & new_node) { bstree_algo::push_back(header, new_node); splay_up(new_node, header); } //! @copydoc ::boost::intrusive::bstree_algorithms::push_front(const node_ptr&,const node_ptr&) //! Additional note: the inserted node is splayed static void push_front(const node_ptr & header, const node_ptr & new_node) { bstree_algo::push_front(header, new_node); splay_up(new_node, header); } //! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_check(const const_node_ptr&,const KeyType&,KeyNodePtrCompare,insert_commit_data&) //! Additional note: nodes with the given key are splayed template<class KeyType, class KeyNodePtrCompare> static std::pair<node_ptr, bool> insert_unique_check (const node_ptr & header, const KeyType &key ,KeyNodePtrCompare comp, insert_commit_data &commit_data) { splay_down(header, key, comp); return bstree_algo::insert_unique_check(header, key, comp, commit_data); } //! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_check(const const_node_ptr&,const node_ptr&,const KeyType&,KeyNodePtrCompare,insert_commit_data&) //! Additional note: nodes with the given key are splayed template<class KeyType, class KeyNodePtrCompare> static std::pair<node_ptr, bool> insert_unique_check (const node_ptr & header, const node_ptr &hint, const KeyType &key ,KeyNodePtrCompare comp, insert_commit_data &commit_data) { splay_down(header, key, comp); return bstree_algo::insert_unique_check(header, hint, key, comp, commit_data); } #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED //! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_commit(const node_ptr&,const node_ptr&,const insert_commit_data&) static void insert_unique_commit (const node_ptr & header, const node_ptr & new_value, const insert_commit_data &commit_data); //! @copydoc ::boost::intrusive::bstree_algorithms::is_header static bool is_header(const const_node_ptr & p); //! @copydoc ::boost::intrusive::bstree_algorithms::rebalance static void rebalance(const node_ptr & header); //! @copydoc ::boost::intrusive::bstree_algorithms::rebalance_subtree static node_ptr rebalance_subtree(const node_ptr & old_root); #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED // bottom-up splay, use data_ as parent for n | complexity : logarithmic | exception : nothrow static void splay_up(const node_ptr & node, const node_ptr & header) { priv_splay_up<true>(node, header); } // top-down splay | complexity : logarithmic | exception : strong, note A template<class KeyType, class KeyNodePtrCompare> static node_ptr splay_down(const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp, bool *pfound = 0) { return priv_splay_down<true>(header, key, comp, pfound); } private: /// @cond // bottom-up splay, use data_ as parent for n | complexity : logarithmic | exception : nothrow template<bool SimpleSplay> static void priv_splay_up(const node_ptr & node, const node_ptr & header) { // If (node == header) do a splay for the right most node instead // this is to boost performance of equal_range/count on equivalent containers in the case // where there are many equal elements at the end node_ptr n((node == header) ? NodeTraits::get_right(header) : node); node_ptr t(header); if( n == t ) return; for( ;; ){ node_ptr p(NodeTraits::get_parent(n)); node_ptr g(NodeTraits::get_parent(p)); if( p == t ) break; if( g == t ){ // zig rotate(n); } else if ((NodeTraits::get_left(p) == n && NodeTraits::get_left(g) == p) || (NodeTraits::get_right(p) == n && NodeTraits::get_right(g) == p) ){ // zig-zig rotate(p); rotate(n); } else { // zig-zag rotate(n); if(!SimpleSplay){ rotate(n); } } } } template<bool SimpleSplay, class KeyType, class KeyNodePtrCompare> static node_ptr priv_splay_down(const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp, bool *pfound = 0) { //Most splay tree implementations use a dummy/null node to implement. //this function. This has some problems for a generic library like Intrusive: // // * The node might not have a default constructor. // * The default constructor could throw. // //We already have a header node. Leftmost and rightmost nodes of the tree //are not changed when splaying (because the invariants of the tree don't //change) We can back up them, use the header as the null node and //reassign old values after the function has been completed. node_ptr const old_root = NodeTraits::get_parent(header); node_ptr const leftmost = NodeTraits::get_left(header); node_ptr const rightmost = NodeTraits::get_right(header); if(leftmost == rightmost){ //Empty or unique node if(pfound){ *pfound = old_root && !comp(key, old_root) && !comp(old_root, key); } return old_root ? old_root : header; } else{ //Initialize "null node" (the header in our case) NodeTraits::set_left (header, node_ptr()); NodeTraits::set_right(header, node_ptr()); //Class that will backup leftmost/rightmost from header, commit the assemble(), //and will restore leftmost/rightmost to header even if "comp" throws detail::splaydown_assemble_and_fix_header<NodeTraits> commit(old_root, header, leftmost, rightmost); bool found = false; for( ;; ){ if(comp(key, commit.t_)){ node_ptr const t_left = NodeTraits::get_left(commit.t_); if(!t_left) break; if(comp(key, t_left)){ bstree_algo::rotate_right_no_parent_fix(commit.t_, t_left); commit.t_ = t_left; if( !NodeTraits::get_left(commit.t_) ) break; link_right(commit.t_, commit.r_); } else{ link_right(commit.t_, commit.r_); if(!SimpleSplay && comp(t_left, key)){ if( !NodeTraits::get_right(commit.t_) ) break; link_left(commit.t_, commit.l_); } } } else if(comp(commit.t_, key)){ node_ptr const t_right = NodeTraits::get_right(commit.t_); if(!t_right) break; if(comp(t_right, key)){ bstree_algo::rotate_left_no_parent_fix(commit.t_, t_right); commit.t_ = t_right; if( !NodeTraits::get_right(commit.t_) ) break; link_left(commit.t_, commit.l_); } else{ link_left(commit.t_, commit.l_); if(!SimpleSplay && comp(key, t_right)){ if( !NodeTraits::get_left(commit.t_) ) break; link_right(commit.t_, commit.r_); } } } else{ found = true; break; } } //commit.~splaydown_assemble_and_fix_header<NodeTraits>() will first //"assemble()" + link the new root & recover header's leftmost & rightmost if(pfound){ *pfound = found; } return commit.t_; } } // break link to left child node and attach it to left tree pointed to by l | complexity : constant | exception : nothrow static void link_left(node_ptr & t, node_ptr & l) { //procedure link_left; // t, l, right(l) := right(t), t, t //end link_left NodeTraits::set_right(l, t); NodeTraits::set_parent(t, l); l = t; t = NodeTraits::get_right(t); } // break link to right child node and attach it to right tree pointed to by r | complexity : constant | exception : nothrow static void link_right(node_ptr & t, node_ptr & r) { //procedure link_right; // t, r, left(r) := left(t), t, t //end link_right; NodeTraits::set_left(r, t); NodeTraits::set_parent(t, r); r = t; t = NodeTraits::get_left(t); } // rotate n with its parent | complexity : constant | exception : nothrow static void rotate(const node_ptr & n) { //procedure rotate_left; // t, right(t), left(right(t)) := right(t), left(right(t)), t //end rotate_left; node_ptr p = NodeTraits::get_parent(n); node_ptr g = NodeTraits::get_parent(p); //Test if g is header before breaking tree //invariants that would make is_header invalid bool g_is_header = bstree_algo::is_header(g); if(NodeTraits::get_left(p) == n){ NodeTraits::set_left(p, NodeTraits::get_right(n)); if(NodeTraits::get_left(p)) NodeTraits::set_parent(NodeTraits::get_left(p), p); NodeTraits::set_right(n, p); } else{ // must be ( p->right == n ) NodeTraits::set_right(p, NodeTraits::get_left(n)); if(NodeTraits::get_right(p)) NodeTraits::set_parent(NodeTraits::get_right(p), p); NodeTraits::set_left(n, p); } NodeTraits::set_parent(p, n); NodeTraits::set_parent(n, g); if(g_is_header){ if(NodeTraits::get_parent(g) == p) NodeTraits::set_parent(g, n); else{//must be ( g->right == p ) BOOST_INTRUSIVE_INVARIANT_ASSERT(false); NodeTraits::set_right(g, n); } } else{ if(NodeTraits::get_left(g) == p) NodeTraits::set_left(g, n); else //must be ( g->right == p ) NodeTraits::set_right(g, n); } } /// @endcond }; /// @cond template<class NodeTraits> struct get_algo<SplayTreeAlgorithms, NodeTraits> { typedef splaytree_algorithms<NodeTraits> type; }; template <class ValueTraits, class NodePtrCompare, class ExtraChecker> struct get_node_checker<SplayTreeAlgorithms, ValueTraits, NodePtrCompare, ExtraChecker> { typedef detail::bstree_node_checker<ValueTraits, NodePtrCompare, ExtraChecker> type; }; /// @endcond } //namespace intrusive } //namespace boost #include <boost/intrusive/detail/config_end.hpp> #endif //BOOST_INTRUSIVE_SPLAYTREE_ALGORITHMS_HPP