| ///////////////////////////////////////////////////////////////////////////// |
| // |
| // (C) Copyright Ion Gaztanaga 2006-2008. |
| // |
| // 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_TRIE_ALGORITHMS_HPP |
| #define BOOST_INTRUSIVE_TRIE_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>: Nothing. |
| template<class NodePriorityCompare> |
| static void unlink(node_ptr node, NodePriorityCompare prio) |
| { |
| node_ptr x = NodeTraits::get_parent(node); |
| if(x){ |
| while(!is_header(x)) |
| x = NodeTraits::get_parent(x); |
| erase(x, node, prio); |
| } |
| } |
| |
| //! <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>: Nothing. |
| template<class NodePriorityCompare> |
| static node_ptr erase(node_ptr header, node_ptr z, NodePriorityCompare 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. |
| //! |
| //! <b>Effects</b>: Inserts new_node into the tree before the upper bound |
| //! according to "comp". |
| //! |
| //! <b>Complexity</b>: Average complexity for insert element is at |
| //! most logarithmic. |
| //! |
| //! <b>Throws</b>: If "comp" throws. |
| template<class NodePtrCompare, class PriorityNodeCompare> |
| static node_ptr insert_equal_upper_bound |
| (node_ptr h, node_ptr new_node, NodePtrCompare comp, PriorityNodeCompare pcomp) |
| { |
| insert_commit_data commit_data; |
| tree_algorithms::insert_equal_upper_bound_check(h, new_node, comp, commit_data); |
| rebalance_after_insertion_check(h, commit_data.node, new_node, pcomp, commit_data.rotations); |
| tree_algorithms::insert_unique_commit(h, new_node, commit_data); |
| rebalance_after_insertion_commit(h, new_node, commit_data.rotations); |
| 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. |
| //! |
| //! <b>Effects</b>: Inserts new_node into the tree before the lower bound |
| //! according to "comp". |
| //! |
| //! <b>Complexity</b>: Average complexity for insert element is at |
| //! most logarithmic. |
| //! |
| //! <b>Throws</b>: If "comp" throws. |
| template<class NodePtrCompare, class NodePriorityCompare> |
| static node_ptr insert_equal_lower_bound |
| (node_ptr h, node_ptr new_node, NodePtrCompare comp, NodePriorityCompare pcomp) |
| { |
| insert_commit_data commit_data; |
| tree_algorithms::insert_equal_lower_bound_check(h, new_node, comp, commit_data); |
| rebalance_after_insertion_check(h, commit_data.node, new_node, pcomp, commit_data.rotations); |
| tree_algorithms::insert_unique_commit(h, new_node, commit_data); |
| rebalance_after_insertion_commit(h, new_node, commit_data.rotations); |
| 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. |
| //! |
| //! <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). |
| //! |
| //! <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" throws. |
| template<class NodePtrCompare, class NodePriorityCompare> |
| static node_ptr insert_equal |
| (node_ptr h, node_ptr hint, node_ptr new_node, NodePtrCompare comp, NodePriorityCompare pcomp) |
| { |
| insert_commit_data commit_data; |
| tree_algorithms::insert_equal_check(h, hint, new_node, comp, commit_data); |
| rebalance_after_insertion_check(h, commit_data.node, new_node, pcomp, commit_data.rotations); |
| tree_algorithms::insert_unique_commit(h, new_node, commit_data); |
| rebalance_after_insertion_commit(h, new_node, commit_data.rotations); |
| return new_node; |
| } |
| |
| //! <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 NodePriorityCompare> |
| static void rebalance_for_erasure(node_ptr header, node_ptr z, NodePriorityCompare 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 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 to 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 NodePriorityCompare> |
| static bool check_invariant(const_node_ptr header, NodePriorityCompare 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_TRIE_ALGORITHMS_HPP |