///////////////////////////////////////////////////////////////////////////// | |
// | |
// (C) Copyright Ion Gaztanaga 2007. | |
// | |
// 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 code has been modified and (supposely) improved by Ion Gaztanaga. | |
// Here is the header of the file used as base code: | |
// | |
// splay_tree.h -- implementation of a STL complatible 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. | |
// | |
// Please send questions, comments, complaints, performance data, etc to | |
// ralf.mattethat@teknologisk.dk | |
// | |
// Requirements for element type | |
// * must be copy-constructible | |
// * destructor must not throw exception | |
// | |
// Methods marked with note A only throws an exception if the evaluation of the | |
// predicate throws an exception. If an exception is thrown the call has no | |
// effect on the containers state | |
// | |
// Methods marked with note B only throws an exception if the coppy constructor | |
// or assignment operator of the predicate throws an exception. If an exception | |
// is thrown the call has no effect on the containers state | |
// | |
// iterators are only invalidated, if the element pointed to by the iterator | |
// is deleted. The same goes for element references | |
// | |
#ifndef BOOST_INTRUSIVE_SPLAYTREE_ALGORITHMS_HPP | |
#define BOOST_INTRUSIVE_SPLAYTREE_ALGORITHMS_HPP | |
#include <boost/intrusive/detail/config_begin.hpp> | |
#include <boost/intrusive/detail/assert.hpp> | |
#include <boost/intrusive/intrusive_fwd.hpp> | |
#include <cstddef> | |
#include <boost/intrusive/detail/utilities.hpp> | |
#include <boost/intrusive/detail/tree_algorithms.hpp> | |
namespace boost { | |
namespace intrusive { | |
/// @cond | |
namespace detail { | |
template<class NodeTraits> | |
struct splaydown_rollback | |
{ | |
typedef typename NodeTraits::node_ptr node_ptr; | |
splaydown_rollback( const node_ptr *pcur_subtree, node_ptr header | |
, node_ptr leftmost , node_ptr rightmost) | |
: pcur_subtree_(pcur_subtree) , header_(header) | |
, leftmost_(leftmost) , rightmost_(rightmost) | |
{} | |
void release() | |
{ pcur_subtree_ = 0; } | |
~splaydown_rollback() | |
{ | |
if(pcur_subtree_){ | |
//Exception can only be thrown by comp, but | |
//tree invariants still hold. *pcur_subtree is the current root | |
//so link it to the header. | |
NodeTraits::set_parent(*pcur_subtree_, header_); | |
NodeTraits::set_parent(header_, *pcur_subtree_); | |
//Recover leftmost/rightmost pointers | |
NodeTraits::set_left (header_, leftmost_); | |
NodeTraits::set_right(header_, rightmost_); | |
} | |
} | |
const node_ptr *pcur_subtree_; | |
node_ptr header_, 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 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 splaytree_algorithms | |
{ | |
/// @cond | |
private: | |
typedef detail::tree_algorithms<NodeTraits> tree_algorithms; | |
/// @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 tree_algorithms::insert_commit_data insert_commit_data; | |
/// @cond | |
private: | |
static node_ptr uncast(const_node_ptr ptr) | |
{ | |
return node_ptr(const_cast<node*>(::boost::intrusive::detail::boost_intrusive_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); } | |
//! <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); } | |
static void unlink(node_ptr node) | |
{ tree_algorithms::unlink(node); } | |
//! <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>: 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>: "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>: 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>: 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>: "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_value, const insert_commit_data &commit_data) | |
{ tree_algorithms::insert_unique_commit(header, new_value, 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> | |
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 tree_algorithms::insert_unique_check(header, key, comp, commit_data); | |
} | |
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 tree_algorithms::insert_unique_check(header, hint, key, comp, commit_data); | |
} | |
static bool is_header(const_node_ptr p) | |
{ return tree_algorithms::is_header(p); } | |
//! <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, bool splay = true) | |
{ | |
if(splay) | |
splay_down(uncast(header), key, comp); | |
node_ptr end = uncast(header); | |
node_ptr y = lower_bound(header, key, comp, false); | |
node_ptr r = (y == end || comp(key, y)) ? end : y; | |
return r; | |
} | |
//! <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, bool splay = true) | |
{ | |
//if(splay) | |
//splay_down(uncast(header), key, comp); | |
std::pair<node_ptr, node_ptr> ret = | |
tree_algorithms::equal_range(header, key, comp); | |
if(splay) | |
splay_up(ret.first, uncast(header)); | |
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. 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, bool splay = true) | |
{ | |
//if(splay) | |
//splay_down(uncast(header), key, comp); | |
node_ptr y = tree_algorithms::lower_bound(header, key, comp); | |
if(splay) | |
splay_up(y, uncast(header)); | |
return y; | |
} | |
//! <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, bool splay = true) | |
{ | |
//if(splay) | |
//splay_down(uncast(header), key, comp); | |
node_ptr y = tree_algorithms::upper_bound(header, key, comp); | |
if(splay) | |
splay_up(y, uncast(header)); | |
return y; | |
} | |
//! <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> | |
static node_ptr insert_equal | |
(node_ptr header, node_ptr hint, node_ptr new_node, NodePtrCompare comp) | |
{ | |
splay_down(header, new_node, comp); | |
return tree_algorithms::insert_equal(header, hint, new_node, comp); | |
} | |
//! <b>Requires</b>: "header" must be the header node of a tree. | |
//! "pos" must be a valid iterator or header (end) node. | |
//! "pos" must be an iterator 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. | |
//! | |
//! <b>Effects</b>: Inserts new_node into the tree before "pos". | |
//! | |
//! <b>Complexity</b>: Constant-time. | |
//! | |
//! <b>Throws</b>: Nothing. | |
//! | |
//! <b>Note</b>: If "pos" is not the successor of the newly inserted "new_node" | |
//! tree invariants might be broken. | |
static node_ptr insert_before | |
(node_ptr header, node_ptr pos, node_ptr new_node) | |
{ | |
tree_algorithms::insert_before(header, pos, new_node); | |
splay_up(new_node, header); | |
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. | |
//! | |
//! <b>Effects</b>: Inserts new_node into the tree before "pos". | |
//! | |
//! <b>Complexity</b>: Constant-time. | |
//! | |
//! <b>Throws</b>: Nothing. | |
//! | |
//! <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". | |
static void push_back(node_ptr header, node_ptr new_node) | |
{ | |
tree_algorithms::push_back(header, new_node); | |
splay_up(new_node, header); | |
} | |
//! <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. | |
//! | |
//! <b>Effects</b>: Inserts new_node into the tree before "pos". | |
//! | |
//! <b>Complexity</b>: Constant-time. | |
//! | |
//! <b>Throws</b>: Nothing. | |
//! | |
//! <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". | |
static void push_front(node_ptr header, node_ptr new_node) | |
{ | |
tree_algorithms::push_front(header, new_node); | |
splay_up(new_node, header); | |
} | |
//! <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. | |
//! | |
//! <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> | |
static node_ptr insert_equal_upper_bound | |
(node_ptr header, node_ptr new_node, NodePtrCompare comp) | |
{ | |
splay_down(header, new_node, comp); | |
return tree_algorithms::insert_equal_upper_bound(header, new_node, comp); | |
} | |
//! <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. | |
//! | |
//! <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> | |
static node_ptr insert_equal_lower_bound | |
(node_ptr header, node_ptr new_node, NodePtrCompare comp) | |
{ | |
splay_down(header, new_node, comp); | |
return tree_algorithms::insert_equal_lower_bound(header, new_node, comp); | |
} | |
//! <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); } | |
// delete node | complexity : constant | exception : nothrow | |
static void erase(node_ptr header, node_ptr z, bool splay = true) | |
{ | |
// node_base* n = t->right; | |
// if( t->left != 0 ){ | |
// node_base* l = t->previous(); | |
// splay_up( l , t ); | |
// n = t->left; | |
// n->right = t->right; | |
// if( n->right != 0 ) | |
// n->right->parent = n; | |
// } | |
// | |
// if( n != 0 ) | |
// n->parent = t->parent; | |
// | |
// if( t->parent->left == t ) | |
// t->parent->left = n; | |
// else // must be ( t->parent->right == t ) | |
// t->parent->right = n; | |
// | |
// if( data_->parent == t ) | |
// data_->parent = find_leftmost(); | |
//posibility 1 | |
if(splay && NodeTraits::get_left(z)){ | |
splay_up(prev_node(z), header); | |
} | |
/* | |
//possibility 2 | |
if(splay && NodeTraits::get_left(z) != 0 ){ | |
node_ptr l = NodeTraits::get_left(z); | |
splay_up(l, header); | |
}*//* | |
if(splay && NodeTraits::get_left(z) != 0 ){ | |
node_ptr l = prev_node(z); | |
splay_up_impl(l, z); | |
}*/ | |
/* | |
//possibility 4 | |
if(splay){ | |
splay_up(z, header); | |
}*/ | |
//if(splay) | |
//splay_up(z, header); | |
tree_algorithms::erase(header, z); | |
} | |
// bottom-up splay, use data_ as parent for n | complexity : logarithmic | exception : nothrow | |
static void splay_up(node_ptr n, node_ptr header) | |
{ | |
if(n == 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 | |
n = NodeTraits::get_right(header); | |
} | |
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); | |
rotate(n); | |
} | |
} | |
} | |
// 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) | |
{ | |
if(!NodeTraits::get_parent(header)) | |
return header; | |
//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 t = NodeTraits::get_parent(header); | |
//Check if tree has a single node | |
if(!NodeTraits::get_left(t) && !NodeTraits::get_right(t)) | |
return t; | |
//Backup leftmost/rightmost | |
node_ptr leftmost (NodeTraits::get_left(header)); | |
node_ptr rightmost(NodeTraits::get_right(header)); | |
{ | |
detail::splaydown_rollback<NodeTraits> rollback(&t, header, leftmost, rightmost); | |
node_ptr null = header; | |
node_ptr l = null; | |
node_ptr r = null; | |
for( ;; ){ | |
if(comp(key, t)){ | |
if(NodeTraits::get_left(t) == 0 ) | |
break; | |
if(comp(key, NodeTraits::get_left(t))){ | |
t = tree_algorithms::rotate_right(t); | |
if(NodeTraits::get_left(t) == 0) | |
break; | |
link_right(t, r); | |
} | |
else if(comp(NodeTraits::get_left(t), key)){ | |
link_right(t, r); | |
if(NodeTraits::get_right(t) == 0 ) | |
break; | |
link_left(t, l); | |
} | |
else{ | |
link_right(t, r); | |
} | |
} | |
else if(comp(t, key)){ | |
if(NodeTraits::get_right(t) == 0 ) | |
break; | |
if(comp(NodeTraits::get_right(t), key)){ | |
t = tree_algorithms::rotate_left( t ); | |
if(NodeTraits::get_right(t) == 0 ) | |
break; | |
link_left(t, l); | |
} | |
else if(comp(key, NodeTraits::get_right(t))){ | |
link_left(t, l); | |
if(NodeTraits::get_left(t) == 0) | |
break; | |
link_right(t, r); | |
} | |
else{ | |
link_left(t, l); | |
} | |
} | |
else{ | |
break; | |
} | |
} | |
assemble(t, l, r, null); | |
rollback.release(); | |
} | |
//t is the current root | |
NodeTraits::set_parent(header, t); | |
NodeTraits::set_parent(t, header); | |
//Recover leftmost/rightmost pointers | |
NodeTraits::set_left (header, leftmost); | |
NodeTraits::set_right(header, rightmost); | |
return t; | |
} | |
//! <b>Requires</b>: header must be the header of a tree. | |
//! | |
//! <b>Effects</b>: Rebalances the tree. | |
//! | |
//! <b>Throws</b>: Nothing. | |
//! | |
//! <b>Complexity</b>: Linear. | |
static void rebalance(node_ptr header) | |
{ tree_algorithms::rebalance(header); } | |
//! <b>Requires</b>: old_root is a node of a tree. | |
//! | |
//! <b>Effects</b>: Rebalances the subtree rooted at old_root. | |
//! | |
//! <b>Returns</b>: The new root of the subtree. | |
//! | |
//! <b>Throws</b>: Nothing. | |
//! | |
//! <b>Complexity</b>: Linear. | |
static node_ptr rebalance_subtree(node_ptr old_root) | |
{ return tree_algorithms::rebalance_subtree(old_root); } | |
//! <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); } | |
private: | |
/// @cond | |
// assemble the three sub-trees into new tree pointed to by t | complexity : constant | exception : nothrow | |
static void assemble( node_ptr t, node_ptr l, node_ptr r, const_node_ptr null_node ) | |
{ | |
NodeTraits::set_right(l, NodeTraits::get_left(t)); | |
NodeTraits::set_left(r, NodeTraits::get_right(t)); | |
if(NodeTraits::get_right(l) != 0){ | |
NodeTraits::set_parent(NodeTraits::get_right(l), l); | |
} | |
if(NodeTraits::get_left(r) != 0){ | |
NodeTraits::set_parent(NodeTraits::get_left(r), r); | |
} | |
NodeTraits::set_left (t, NodeTraits::get_right(null_node)); | |
NodeTraits::set_right(t, NodeTraits::get_left(null_node)); | |
if( NodeTraits::get_left(t) != 0 ){ | |
NodeTraits::set_parent(NodeTraits::get_left(t), t); | |
} | |
if( NodeTraits::get_right(t) ){ | |
NodeTraits::set_parent(NodeTraits::get_right(t), 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) | |
{ | |
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) | |
{ | |
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) | |
{ | |
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 = is_header(g); | |
if(NodeTraits::get_left(p) == n){ | |
NodeTraits::set_left(p, NodeTraits::get_right(n)); | |
if(NodeTraits::get_left(p) != 0) | |
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) != 0) | |
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(0); | |
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 | |
}; | |
} //namespace intrusive | |
} //namespace boost | |
#include <boost/intrusive/detail/config_end.hpp> | |
#endif //BOOST_INTRUSIVE_SPLAYTREE_ALGORITHMS_HPP |