| ///////////////////////////////////////////////////////////////////////////// |
| // |
| // (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(node_ptr t, node_ptr header, node_ptr leftmost, 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(node_ptr,node_ptr) |
| static void swap_nodes(node_ptr node1, node_ptr node2); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(node_ptr,node_ptr,node_ptr,node_ptr) |
| static void swap_nodes(node_ptr node1, node_ptr header1, node_ptr node2, node_ptr header2); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(node_ptr,node_ptr) |
| static void replace_node(node_ptr node_to_be_replaced, node_ptr new_node); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(node_ptr,node_ptr,node_ptr) |
| static void replace_node(node_ptr node_to_be_replaced, node_ptr header, node_ptr new_node); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::unlink(node_ptr) |
| static void unlink(node_ptr node); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::unlink_leftmost_without_rebalance |
| static node_ptr unlink_leftmost_without_rebalance(node_ptr header); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::unique(const const_node_ptr&) |
| static bool unique(const_node_ptr node); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::size(const const_node_ptr&) |
| static std::size_t size(const_node_ptr header); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::next_node(const node_ptr&) |
| static node_ptr next_node(node_ptr node); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::prev_node(const node_ptr&) |
| static node_ptr prev_node(node_ptr node); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::init(node_ptr) |
| static void init(node_ptr node); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::init_header(node_ptr) |
| static void init_header(node_ptr header); |
| |
| #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::erase(node_ptr,node_ptr) |
| //! Additional notes: the previous node of z is splayed to speed up range deletions. |
| static void erase(node_ptr header, 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); |
| } |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::transfer_unique |
| template<class NodePtrCompare> |
| static bool transfer_unique |
| (node_ptr header1, NodePtrCompare comp, node_ptr header2, node_ptr z) |
| { |
| typename bstree_algo::insert_commit_data commit_data; |
| bool const transferable = bstree_algo::insert_unique_check(header1, z, comp, commit_data).second; |
| if(transferable){ |
| erase(header2, z); |
| bstree_algo::insert_commit(header1, z, commit_data); |
| splay_up(z, header1); |
| } |
| return transferable; |
| } |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::transfer_equal |
| template<class NodePtrCompare> |
| static void transfer_equal |
| (node_ptr header1, NodePtrCompare comp, node_ptr header2, node_ptr z) |
| { |
| insert_commit_data commit_data; |
| splay_down(header1, z, comp); |
| bstree_algo::insert_equal_upper_bound_check(header1, z, comp, commit_data); |
| erase(header2, z); |
| bstree_algo::insert_commit(header1, z, commit_data); |
| } |
| |
| #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED |
| //! @copydoc ::boost::intrusive::bstree_algorithms::clone(const const_node_ptr&,node_ptr,Cloner,Disposer) |
| template <class Cloner, class Disposer> |
| static void clone |
| (const_node_ptr source_header, 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(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 |
| (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_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 |
| (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_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 |
| (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_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 |
| (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_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 |
| (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_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 |
| (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_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 |
| (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_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(node_ptr,node_ptr,NodePtrCompare) |
| //! Additional note: the inserted node is splayed |
| template<class NodePtrCompare> |
| static node_ptr insert_equal_upper_bound |
| (node_ptr header, 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(node_ptr,node_ptr,NodePtrCompare) |
| //! Additional note: the inserted node is splayed |
| template<class NodePtrCompare> |
| static node_ptr insert_equal_lower_bound |
| (node_ptr header, 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(node_ptr,node_ptr,node_ptr,NodePtrCompare) |
| //! Additional note: the inserted node is splayed |
| template<class NodePtrCompare> |
| static node_ptr insert_equal |
| (node_ptr header, node_ptr hint, 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(node_ptr,node_ptr,node_ptr) |
| //! Additional note: the inserted node is splayed |
| static node_ptr insert_before |
| (node_ptr header, node_ptr pos, 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(node_ptr,node_ptr) |
| //! Additional note: the inserted node is splayed |
| static void push_back(node_ptr header, node_ptr new_node) |
| { |
| bstree_algo::push_back(header, new_node); |
| splay_up(new_node, header); |
| } |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::push_front(node_ptr,node_ptr) |
| //! Additional note: the inserted node is splayed |
| static void push_front(node_ptr header, 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 |
| (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 |
| (node_ptr header, 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(node_ptr,node_ptr,const insert_commit_data&) |
| static void insert_unique_commit |
| (node_ptr header, node_ptr new_value, const insert_commit_data &commit_data); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::is_header |
| static bool is_header(const_node_ptr p); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::rebalance |
| static void rebalance(node_ptr header); |
| |
| //! @copydoc ::boost::intrusive::bstree_algorithms::rebalance_subtree |
| static node_ptr rebalance_subtree(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(node_ptr node, 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(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(node_ptr node, 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(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(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 |
