boost/intrusive/treap_algorithms.hpp
///////////////////////////////////////////////////////////////////////////// // // (C) Copyright Ion Gaztanaga 2006-2009. // // 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 <cstddef> #include <boost/intrusive/intrusive_fwd.hpp> #include <boost/intrusive/detail/assert.hpp> #include <boost/intrusive/detail/utilities.hpp> #include <boost/intrusive/detail/tree_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 circular list //! //! <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 { 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: class remove_on_destroy { remove_on_destroy(const remove_on_destroy&); remove_on_destroy& operator=(const remove_on_destroy&); public: remove_on_destroy(node_ptr header, node_ptr z) : header_(header), z_(z), remove_it_(true) {} ~remove_on_destroy() { if(remove_it_){ tree_algorithms::erase(header_, z_); } } void release() { remove_it_ = false; } const node_ptr header_; const node_ptr z_; bool remove_it_; }; class rerotate_on_destroy { rerotate_on_destroy(const remove_on_destroy&); rerotate_on_destroy& operator=(const rerotate_on_destroy&); public: rerotate_on_destroy(node_ptr header, 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) { for( node_ptr p_parent = NodeTraits::get_parent(p) ; n-- ; p_parent = NodeTraits::get_parent(p)){ //Check if left child if(p == NodeTraits::get_left(p_parent)){ tree_algorithms::rotate_right(p_parent, header); } else{ //Right child tree_algorithms::rotate_left(p_parent, header); } } } typedef detail::tree_algorithms<NodeTraits> tree_algorithms; static node_ptr uncast(const_node_ptr ptr) { return node_ptr(const_cast<node*>(::boost::intrusive::detail::get_pointer(ptr))); } /// @endcond public: static node_ptr begin_node(const_node_ptr header) { return tree_algorithms::begin_node(header); } static node_ptr end_node(const_node_ptr header) { return tree_algorithms::end_node(header); } //! This type is the information that will be //! filled by insert_unique_check struct insert_commit_data /// @cond : public tree_algorithms::insert_commit_data /// @endcond { /// @cond std::size_t rotations; /// @endcond }; //! <b>Requires</b>: header1 and header2 must be the header nodes //! of two trees. //! //! <b>Effects</b>: Swaps two trees. After the function header1 will contain //! links to the second tree and header2 will have links to the first tree. //! //! <b>Complexity</b>: Constant. //! //! <b>Throws</b>: Nothing. static void swap_tree(node_ptr header1, node_ptr header2) { return tree_algorithms::swap_tree(header1, header2); } //! <b>Requires</b>: node1 and node2 can't be header nodes //! of two trees. //! //! <b>Effects</b>: Swaps two nodes. After the function node1 will be inserted //! in the position node2 before the function. node2 will be inserted in the //! position node1 had before the function. //! //! <b>Complexity</b>: Logarithmic. //! //! <b>Throws</b>: Nothing. //! //! <b>Note</b>: This function will break container ordering invariants if //! node1 and node2 are not equivalent according to the ordering rules. //! //!Experimental function static void swap_nodes(node_ptr node1, node_ptr node2) { if(node1 == node2) return; node_ptr header1(tree_algorithms::get_header(node1)), header2(tree_algorithms::get_header(node2)); swap_nodes(node1, header1, node2, header2); } //! <b>Requires</b>: node1 and node2 can't be header nodes //! of two trees with header header1 and header2. //! //! <b>Effects</b>: Swaps two nodes. After the function node1 will be inserted //! in the position node2 before the function. node2 will be inserted in the //! position node1 had before the function. //! //! <b>Complexity</b>: Constant. //! //! <b>Throws</b>: Nothing. //! //! <b>Note</b>: This function will break container ordering invariants if //! node1 and node2 are not equivalent according to the ordering rules. //! //!Experimental function static void swap_nodes(node_ptr node1, node_ptr header1, node_ptr node2, node_ptr header2) { tree_algorithms::swap_nodes(node1, header1, node2, header2); } //! <b>Requires</b>: node_to_be_replaced must be inserted in a tree //! and new_node must not be inserted in a tree. //! //! <b>Effects</b>: Replaces node_to_be_replaced in its position in the //! tree with new_node. The tree does not need to be rebalanced //! //! <b>Complexity</b>: Logarithmic. //! //! <b>Throws</b>: Nothing. //! //! <b>Note</b>: This function will break container ordering invariants if //! new_node is not equivalent to node_to_be_replaced according to the //! ordering rules. This function is faster than erasing and inserting //! the node, since no rebalancing and comparison is needed. //! //!Experimental function static void replace_node(node_ptr node_to_be_replaced, node_ptr new_node) { if(node_to_be_replaced == new_node) return; replace_node(node_to_be_replaced, tree_algorithms::get_header(node_to_be_replaced), new_node); } //! <b>Requires</b>: node_to_be_replaced must be inserted in a tree //! with header "header" and new_node must not be inserted in a tree. //! //! <b>Effects</b>: Replaces node_to_be_replaced in its position in the //! tree with new_node. The tree does not need to be rebalanced //! //! <b>Complexity</b>: Constant. //! //! <b>Throws</b>: Nothing. //! //! <b>Note</b>: This function will break container ordering invariants if //! new_node is not equivalent to node_to_be_replaced according to the //! ordering rules. This function is faster than erasing and inserting //! the node, since no rebalancing or comparison is needed. //! //!Experimental function static void replace_node(node_ptr node_to_be_replaced, node_ptr header, node_ptr new_node) { tree_algorithms::replace_node(node_to_be_replaced, header, new_node); } //! <b>Requires</b>: node is a tree node but not the header. //! //! <b>Effects</b>: Unlinks the node and rebalances the tree. //! //! <b>Complexity</b>: Average complexity is constant time. //! //! <b>Throws</b>: If "pcomp" throws, strong guarantee template<class NodePtrPriorityCompare> static void unlink(node_ptr node, NodePtrPriorityCompare pcomp) { node_ptr x = NodeTraits::get_parent(node); if(x){ while(!is_header(x)) x = NodeTraits::get_parent(x); erase(x, node, pcomp); } } //! <b>Requires</b>: header is the header of a tree. //! //! <b>Effects</b>: Unlinks the leftmost node from the tree, and //! updates the header link to the new leftmost node. //! //! <b>Complexity</b>: Average complexity is constant time. //! //! <b>Throws</b>: Nothing. //! //! <b>Notes</b>: This function breaks the tree and the tree can //! only be used for more unlink_leftmost_without_rebalance calls. //! This function is normally used to achieve a step by step //! controlled destruction of the tree. static node_ptr unlink_leftmost_without_rebalance(node_ptr header) { return tree_algorithms::unlink_leftmost_without_rebalance(header); } //! <b>Requires</b>: node is a node of the tree or an node initialized //! by init(...). //! //! <b>Effects</b>: Returns true if the node is initialized by init(). //! //! <b>Complexity</b>: Constant time. //! //! <b>Throws</b>: Nothing. static bool unique(const_node_ptr node) { return tree_algorithms::unique(node); } //! <b>Requires</b>: node is a node of the tree but it's not the header. //! //! <b>Effects</b>: Returns the number of nodes of the subtree. //! //! <b>Complexity</b>: Linear time. //! //! <b>Throws</b>: Nothing. static std::size_t count(const_node_ptr node) { return tree_algorithms::count(node); } //! <b>Requires</b>: header is the header node of the tree. //! //! <b>Effects</b>: Returns the number of nodes above the header. //! //! <b>Complexity</b>: Linear time. //! //! <b>Throws</b>: Nothing. static std::size_t size(const_node_ptr header) { return tree_algorithms::size(header); } //! <b>Requires</b>: p is a node from the tree except the header. //! //! <b>Effects</b>: Returns the next node of the tree. //! //! <b>Complexity</b>: Average constant time. //! //! <b>Throws</b>: Nothing. static node_ptr next_node(node_ptr p) { return tree_algorithms::next_node(p); } //! <b>Requires</b>: p is a node from the tree except the leftmost node. //! //! <b>Effects</b>: Returns the previous node of the tree. //! //! <b>Complexity</b>: Average constant time. //! //! <b>Throws</b>: Nothing. static node_ptr prev_node(node_ptr p) { return tree_algorithms::prev_node(p); } //! <b>Requires</b>: node must not be part of any tree. //! //! <b>Effects</b>: After the function unique(node) == true. //! //! <b>Complexity</b>: Constant. //! //! <b>Throws</b>: Nothing. //! //! <b>Nodes</b>: If node is inserted in a tree, this function corrupts the tree. static void init(node_ptr node) { tree_algorithms::init(node); } //! <b>Requires</b>: node must not be part of any tree. //! //! <b>Effects</b>: Initializes the header to represent an empty tree. //! unique(header) == true. //! //! <b>Complexity</b>: Constant. //! //! <b>Throws</b>: Nothing. //! //! <b>Nodes</b>: If node is inserted in a tree, this function corrupts the tree. static void init_header(node_ptr header) { tree_algorithms::init_header(header); } //! <b>Requires</b>: header must be the header of a tree, z a node //! of that tree and z != header. //! //! <b>Effects</b>: Erases node "z" from the tree with header "header". //! //! <b>Complexity</b>: Amortized constant time. //! //! <b>Throws</b>: If "pcomp" throws, strong guarantee. template<class NodePtrPriorityCompare> static node_ptr erase(node_ptr header, node_ptr z, NodePtrPriorityCompare pcomp) { rebalance_for_erasure(header, z, pcomp); tree_algorithms::erase(header, z); // assert(check_invariant(header, pcomp)); return z; } //! <b>Requires</b>: "cloner" must be a function //! object taking a node_ptr and returning a new cloned node of it. "disposer" must //! take a node_ptr and shouldn't throw. //! //! <b>Effects</b>: First empties target tree calling //! <tt>void disposer::operator()(node_ptr)</tt> for every node of the tree //! except the header. //! //! Then, duplicates the entire tree pointed by "source_header" cloning each //! source node with <tt>node_ptr Cloner::operator()(node_ptr)</tt> to obtain //! the nodes of the target tree. If "cloner" throws, the cloned target nodes //! are disposed using <tt>void disposer(node_ptr)</tt>. //! //! <b>Complexity</b>: Linear to the number of element of the source tree plus the. //! number of elements of tree target tree when calling this function. //! //! <b>Throws</b>: If cloner functor throws. If this happens target nodes are disposed. template <class Cloner, class Disposer> static void clone (const_node_ptr source_header, node_ptr target_header, Cloner cloner, Disposer disposer) { tree_algorithms::clone(source_header, target_header, cloner, disposer); } //! <b>Requires</b>: "disposer" must be an object function //! taking a node_ptr parameter and shouldn't throw. //! //! <b>Effects</b>: Empties the target tree calling //! <tt>void disposer::operator()(node_ptr)</tt> for every node of the tree //! except the header. //! //! <b>Complexity</b>: Linear to the number of element of the source tree plus the. //! number of elements of tree target tree when calling this function. //! //! <b>Throws</b>: If cloner functor throws. If this happens target nodes are disposed. template<class Disposer> static void clear_and_dispose(node_ptr header, Disposer disposer) { tree_algorithms::clear_and_dispose(header, disposer); } //! <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. KeyNodePtrCompare can compare KeyType with tree's node_ptrs. //! //! <b>Effects</b>: Returns an node_ptr to the first element that is //! not less than "key" according to "comp" or "header" if that element does //! not exist. //! //! <b>Complexity</b>: Logarithmic. //! //! <b>Throws</b>: If "comp" throws. template<class KeyType, class KeyNodePtrCompare> static node_ptr lower_bound (const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp) { return tree_algorithms::lower_bound(header, key, comp); } //! <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. KeyNodePtrCompare can compare KeyType with tree's node_ptrs. //! //! <b>Effects</b>: Returns an node_ptr to the first element that is greater //! than "key" according to "comp" or "header" if that element does not exist. //! //! <b>Complexity</b>: Logarithmic. //! //! <b>Throws</b>: If "comp" throws. template<class KeyType, class KeyNodePtrCompare> static node_ptr upper_bound (const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp) { return tree_algorithms::upper_bound(header, key, comp); } //! <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. KeyNodePtrCompare can compare KeyType with tree's node_ptrs. //! //! <b>Effects</b>: Returns an node_ptr to the element that is equivalent to //! "key" according to "comp" or "header" if that element does not exist. //! //! <b>Complexity</b>: Logarithmic. //! //! <b>Throws</b>: If "comp" throws. template<class KeyType, class KeyNodePtrCompare> static node_ptr find (const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp) { return tree_algorithms::find(header, key, comp); } //! <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. KeyNodePtrCompare can compare KeyType with tree's node_ptrs. //! //! <b>Effects</b>: Returns an a pair of node_ptr delimiting a range containing //! all elements that are equivalent to "key" according to "comp" or an //! empty range that indicates the position where those elements would be //! if they there are no equivalent elements. //! //! <b>Complexity</b>: Logarithmic. //! //! <b>Throws</b>: If "comp" throws. template<class KeyType, class KeyNodePtrCompare> static std::pair<node_ptr, node_ptr> equal_range (const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp) { return tree_algorithms::equal_range(header, key, comp); } //! <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 (node_ptr h, node_ptr new_node, NodePtrCompare comp, NodePtrPriorityCompare pcomp) { insert_commit_data commit_data; tree_algorithms::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 (node_ptr h, node_ptr new_node, NodePtrCompare comp, NodePtrPriorityCompare pcomp) { insert_commit_data commit_data; tree_algorithms::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 (node_ptr h, node_ptr hint, node_ptr new_node, NodePtrCompare comp, NodePtrPriorityCompare pcomp) { insert_commit_data commit_data; tree_algorithms::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 (node_ptr header, node_ptr pos, node_ptr new_node, NodePtrPriorityCompare pcomp) { insert_commit_data commit_data; tree_algorithms::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(node_ptr header, node_ptr new_node, NodePtrPriorityCompare pcomp) { insert_commit_data commit_data; tree_algorithms::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(node_ptr header, node_ptr new_node, NodePtrPriorityCompare pcomp) { insert_commit_data commit_data; tree_algorithms::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_node_ptr header, const KeyType &key ,KeyNodePtrCompare comp, KeyNodePtrPrioCompare pcomp ,insert_commit_data &commit_data) { std::pair<node_ptr, bool> ret = tree_algorithms::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_node_ptr header, node_ptr hint, const KeyType &key ,KeyNodePtrCompare comp, KeyNodePtrPrioCompare pcomp, insert_commit_data &commit_data) { std::pair<node_ptr, bool> ret = tree_algorithms::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 (node_ptr header, node_ptr new_node, const insert_commit_data &commit_data) { tree_algorithms::insert_unique_commit(header, new_node, commit_data); rebalance_after_insertion_commit(header, new_node, commit_data.rotations); } //! <b>Requires</b>: "n" must be a node inserted in a tree. //! //! <b>Effects</b>: Returns a pointer to the header node of the tree. //! //! <b>Complexity</b>: Logarithmic. //! //! <b>Throws</b>: Nothing. static node_ptr get_header(node_ptr n) { return tree_algorithms::get_header(n); } /// @cond private: //! <b>Requires</b>: p is a node of a tree. //! //! <b>Effects</b>: Returns true if p is the header of the tree. //! //! <b>Complexity</b>: Constant. //! //! <b>Throws</b>: Nothing. static bool is_header(const_node_ptr p) { return tree_algorithms::is_header(p); } template<class NodePtrPriorityCompare> static void rebalance_for_erasure(node_ptr header, 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){ if(!z_right || (z_left && pcomp(z_left, z_right))){ tree_algorithms::rotate_right(z, header); } else{ tree_algorithms::rotate_left(z, 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 (node_ptr h, 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 tree_algorithms::insert_unique_commit(h, new_node, commit_data); rebalance_after_insertion_commit(h, new_node, commit_data.rotations); } template<class Key, class KeyNodePriorityCompare> static void rebalance_after_insertion_check ( const_node_ptr header, const_node_ptr upnode, const Key &k , KeyNodePriorityCompare pcomp, std::size_t &num_rotations) { //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; } static void rebalance_after_insertion_commit(node_ptr header, node_ptr p, std::size_t n) { // Now execute n rotations for( node_ptr p_parent = NodeTraits::get_parent(p) ; n-- ; p_parent = NodeTraits::get_parent(p)){ //Check if left child if(p == NodeTraits::get_left(p_parent)){ tree_algorithms::rotate_right(p_parent, header); } else{ //Right child tree_algorithms::rotate_left(p_parent, header); } } } template<class NodePtrPriorityCompare> static bool check_invariant(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 }; } //namespace intrusive } //namespace boost #include <boost/intrusive/detail/config_end.hpp> #endif //BOOST_INTRUSIVE_TREAP_ALGORITHMS_HPP