boost/intrusive/avltree_algorithms.hpp
/////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Daniel K. O. 2005.
// (C) Copyright Ion Gaztanaga 2007-2014
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/intrusive for documentation.
//
/////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_INTRUSIVE_AVLTREE_ALGORITHMS_HPP
#define BOOST_INTRUSIVE_AVLTREE_ALGORITHMS_HPP
#include <boost/intrusive/detail/config_begin.hpp>
#include <boost/intrusive/intrusive_fwd.hpp>
#include <cstddef>
#include <boost/intrusive/detail/assert.hpp>
#include <boost/intrusive/detail/algo_type.hpp>
#include <boost/intrusive/detail/ebo_functor_holder.hpp>
#include <boost/intrusive/bstree_algorithms.hpp>
#if defined(BOOST_HAS_PRAGMA_ONCE)
# pragma once
#endif
namespace boost {
namespace intrusive {
/// @cond
template<class NodeTraits, class F>
struct avltree_node_cloner
//Use public inheritance to avoid MSVC bugs with closures
: public detail::ebo_functor_holder<F>
{
typedef typename NodeTraits::node_ptr node_ptr;
typedef detail::ebo_functor_holder<F> base_t;
BOOST_INTRUSIVE_FORCEINLINE avltree_node_cloner(F f)
: base_t(f)
{}
node_ptr operator()(node_ptr p)
{
node_ptr n = base_t::get()(p);
NodeTraits::set_balance(n, NodeTraits::get_balance(p));
return n;
}
node_ptr operator()(node_ptr p) const
{
node_ptr n = base_t::get()(p);
NodeTraits::set_balance(n, NodeTraits::get_balance(p));
return n;
}
};
namespace detail {
template<class ValueTraits, class NodePtrCompare, class ExtraChecker>
struct avltree_node_checker
: public bstree_node_checker<ValueTraits, NodePtrCompare, ExtraChecker>
{
typedef bstree_node_checker<ValueTraits, NodePtrCompare, ExtraChecker> base_checker_t;
typedef ValueTraits value_traits;
typedef typename value_traits::node_traits node_traits;
typedef typename node_traits::const_node_ptr const_node_ptr;
struct return_type
: public base_checker_t::return_type
{
return_type() : height(0) {}
int height;
};
avltree_node_checker(const NodePtrCompare& comp, ExtraChecker extra_checker)
: base_checker_t(comp, extra_checker)
{}
void operator () (const_node_ptr p,
const return_type& check_return_left, const return_type& check_return_right,
return_type& check_return)
{
const int height_diff = check_return_right.height - check_return_left.height; (void)height_diff;
BOOST_INTRUSIVE_INVARIANT_ASSERT(
(height_diff == -1 && node_traits::get_balance(p) == node_traits::negative()) ||
(height_diff == 0 && node_traits::get_balance(p) == node_traits::zero()) ||
(height_diff == 1 && node_traits::get_balance(p) == node_traits::positive())
);
check_return.height = 1 +
(check_return_left.height > check_return_right.height ? check_return_left.height : check_return_right.height);
base_checker_t::operator()(p, check_return_left, check_return_right, check_return);
}
};
} // namespace detail
/// @endcond
//! avltree_algorithms is configured with a NodeTraits class, which encapsulates the
//! information about the node to be manipulated. NodeTraits must support the
//! following interface:
//!
//! <b>Typedefs</b>:
//!
//! <tt>node</tt>: The type of the node that forms the binary search tree
//!
//! <tt>node_ptr</tt>: A pointer to a node
//!
//! <tt>const_node_ptr</tt>: A pointer to a const node
//!
//! <tt>balance</tt>: The type of the balance factor
//!
//! <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>
//!
//! <tt>static balance get_balance(const_node_ptr n);</tt>
//!
//! <tt>static void set_balance(node_ptr n, balance b);</tt>
//!
//! <tt>static balance negative();</tt>
//!
//! <tt>static balance zero();</tt>
//!
//! <tt>static balance positive();</tt>
template<class NodeTraits>
class avltree_algorithms
#ifndef BOOST_INTRUSIVE_DOXYGEN_INVOKED
: public bstree_algorithms<NodeTraits>
#endif
{
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;
typedef typename NodeTraits::balance balance;
/// @cond
private:
typedef bstree_algorithms<NodeTraits> bstree_algo;
/// @endcond
public:
//! This type is the information that will be
//! filled by insert_unique_check
typedef typename bstree_algo::insert_commit_data insert_commit_data;
#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
//! @copydoc ::boost::intrusive::bstree_algorithms::get_header(const_node_ptr)
static node_ptr get_header(const_node_ptr n) BOOST_NOEXCEPT;
//! @copydoc ::boost::intrusive::bstree_algorithms::begin_node
static node_ptr begin_node(const_node_ptr header) BOOST_NOEXCEPT;
//! @copydoc ::boost::intrusive::bstree_algorithms::end_node
static node_ptr end_node(const_node_ptr header) BOOST_NOEXCEPT;
//! @copydoc ::boost::intrusive::bstree_algorithms::swap_tree
static void swap_tree(node_ptr header1, node_ptr header2) BOOST_NOEXCEPT;
#endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
//! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(node_ptr,node_ptr)
static void swap_nodes(node_ptr node1, node_ptr node2) BOOST_NOEXCEPT
{
if(node1 == node2)
return;
node_ptr header1(bstree_algo::get_header(node1)), header2(bstree_algo::get_header(node2));
swap_nodes(node1, header1, node2, header2);
}
//! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(node_ptr,node_ptr,node_ptr,node_ptr)
static void swap_nodes(node_ptr node1, node_ptr header1, node_ptr node2, node_ptr header2) BOOST_NOEXCEPT
{
if(node1 == node2) return;
bstree_algo::swap_nodes(node1, header1, node2, header2);
//Swap balance
balance c = NodeTraits::get_balance(node1);
NodeTraits::set_balance(node1, NodeTraits::get_balance(node2));
NodeTraits::set_balance(node2, c);
}
//! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(node_ptr,node_ptr)
static void replace_node(node_ptr node_to_be_replaced, node_ptr new_node) BOOST_NOEXCEPT
{
if(node_to_be_replaced == new_node)
return;
replace_node(node_to_be_replaced, bstree_algo::get_header(node_to_be_replaced), new_node);
}
//! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(node_ptr,node_ptr,node_ptr)
static void replace_node(node_ptr node_to_be_replaced, node_ptr header, node_ptr new_node) BOOST_NOEXCEPT
{
bstree_algo::replace_node(node_to_be_replaced, header, new_node);
NodeTraits::set_balance(new_node, NodeTraits::get_balance(node_to_be_replaced));
}
//! @copydoc ::boost::intrusive::bstree_algorithms::unlink(node_ptr)
static void unlink(node_ptr node) BOOST_NOEXCEPT
{
node_ptr x = NodeTraits::get_parent(node);
if(x){
while(!is_header(x))
x = NodeTraits::get_parent(x);
erase(x, node);
}
}
#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
//! @copydoc ::boost::intrusive::bstree_algorithms::unlink_leftmost_without_rebalance
static node_ptr unlink_leftmost_without_rebalance(node_ptr header) BOOST_NOEXCEPT;
//! @copydoc ::boost::intrusive::bstree_algorithms::unique(const_node_ptr)
static bool unique(const_node_ptr node) BOOST_NOEXCEPT;
//! @copydoc ::boost::intrusive::bstree_algorithms::size(const_node_ptr)
static std::size_t size(const_node_ptr header) BOOST_NOEXCEPT;
//! @copydoc ::boost::intrusive::bstree_algorithms::next_node(node_ptr)
static node_ptr next_node(node_ptr node) BOOST_NOEXCEPT;
//! @copydoc ::boost::intrusive::bstree_algorithms::prev_node(node_ptr)
static node_ptr prev_node(node_ptr node) BOOST_NOEXCEPT;
//! @copydoc ::boost::intrusive::bstree_algorithms::init(node_ptr)
static void init(node_ptr node) BOOST_NOEXCEPT;
#endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
//! <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) BOOST_NOEXCEPT
{
bstree_algo::init_header(header);
NodeTraits::set_balance(header, NodeTraits::zero());
}
//! @copydoc ::boost::intrusive::bstree_algorithms::erase(node_ptr,node_ptr)
static node_ptr erase(node_ptr header, node_ptr z) BOOST_NOEXCEPT
{
typename bstree_algo::data_for_rebalance info;
bstree_algo::erase(header, z, info);
rebalance_after_erasure(header, z, info);
return z;
}
//! @copydoc ::boost::intrusive::bstree_algorithms::transfer_unique
template<class NodePtrCompare>
static bool transfer_unique
(node_ptr header1, NodePtrCompare comp, node_ptr header2, node_ptr z)
{
typename bstree_algo::data_for_rebalance info;
bool const transferred = bstree_algo::transfer_unique(header1, comp, header2, z, info);
if(transferred){
rebalance_after_erasure(header2, z, info);
rebalance_after_insertion(header1, z);
}
return transferred;
}
//! @copydoc ::boost::intrusive::bstree_algorithms::transfer_equal
template<class NodePtrCompare>
static void transfer_equal
(node_ptr header1, NodePtrCompare comp, node_ptr header2, node_ptr z)
{
typename bstree_algo::data_for_rebalance info;
bstree_algo::transfer_equal(header1, comp, header2, z, info);
rebalance_after_erasure(header2, z, info);
rebalance_after_insertion(header1, z);
}
//! @copydoc ::boost::intrusive::bstree_algorithms::clone(const_node_ptr,node_ptr,Cloner,Disposer)
template <class Cloner, class Disposer>
static void clone
(const_node_ptr source_header, node_ptr target_header, Cloner cloner, Disposer disposer)
{
avltree_node_cloner<NodeTraits, Cloner> new_cloner(cloner);
bstree_algo::clone(source_header, target_header, new_cloner, disposer);
}
#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
//! @copydoc ::boost::intrusive::bstree_algorithms::clear_and_dispose(node_ptr,Disposer)
template<class Disposer>
static void clear_and_dispose(node_ptr header, Disposer disposer) BOOST_NOEXCEPT;
//! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound(const_node_ptr,const KeyType&,KeyNodePtrCompare)
template<class KeyType, class KeyNodePtrCompare>
static node_ptr lower_bound
(const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp);
//! @copydoc ::boost::intrusive::bstree_algorithms::upper_bound(const_node_ptr,const KeyType&,KeyNodePtrCompare)
template<class KeyType, class KeyNodePtrCompare>
static node_ptr upper_bound
(const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp);
//! @copydoc ::boost::intrusive::bstree_algorithms::find(const_node_ptr,const KeyType&,KeyNodePtrCompare)
template<class KeyType, class KeyNodePtrCompare>
static node_ptr find
(const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp);
//! @copydoc ::boost::intrusive::bstree_algorithms::equal_range(const_node_ptr,const KeyType&,KeyNodePtrCompare)
template<class KeyType, class KeyNodePtrCompare>
static std::pair<node_ptr, node_ptr> equal_range
(const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp);
//! @copydoc ::boost::intrusive::bstree_algorithms::bounded_range(const_node_ptr,const KeyType&,const KeyType&,KeyNodePtrCompare,bool,bool)
template<class KeyType, class KeyNodePtrCompare>
static std::pair<node_ptr, node_ptr> bounded_range
(const_node_ptr header, const KeyType &lower_key, const KeyType &upper_key, KeyNodePtrCompare comp
, bool left_closed, bool right_closed);
//! @copydoc ::boost::intrusive::bstree_algorithms::count(const_node_ptr,const KeyType&,KeyNodePtrCompare)
template<class KeyType, class KeyNodePtrCompare>
static std::size_t count(const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp);
#endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal_upper_bound(node_ptr,node_ptr,NodePtrCompare)
template<class NodePtrCompare>
static node_ptr insert_equal_upper_bound
(node_ptr h, node_ptr new_node, NodePtrCompare comp)
{
bstree_algo::insert_equal_upper_bound(h, new_node, comp);
rebalance_after_insertion(h, new_node);
return new_node;
}
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal_lower_bound(node_ptr,node_ptr,NodePtrCompare)
template<class NodePtrCompare>
static node_ptr insert_equal_lower_bound
(node_ptr h, node_ptr new_node, NodePtrCompare comp)
{
bstree_algo::insert_equal_lower_bound(h, new_node, comp);
rebalance_after_insertion(h, new_node);
return new_node;
}
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal(node_ptr,node_ptr,node_ptr,NodePtrCompare)
template<class NodePtrCompare>
static node_ptr insert_equal
(node_ptr header, node_ptr hint, node_ptr new_node, NodePtrCompare comp)
{
bstree_algo::insert_equal(header, hint, new_node, comp);
rebalance_after_insertion(header, new_node);
return new_node;
}
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_before(node_ptr,node_ptr,node_ptr)
static node_ptr insert_before
(node_ptr header, node_ptr pos, node_ptr new_node) BOOST_NOEXCEPT
{
bstree_algo::insert_before(header, pos, new_node);
rebalance_after_insertion(header, new_node);
return new_node;
}
//! @copydoc ::boost::intrusive::bstree_algorithms::push_back(node_ptr,node_ptr)
static void push_back(node_ptr header, node_ptr new_node) BOOST_NOEXCEPT
{
bstree_algo::push_back(header, new_node);
rebalance_after_insertion(header, new_node);
}
//! @copydoc ::boost::intrusive::bstree_algorithms::push_front(node_ptr,node_ptr)
static void push_front(node_ptr header, node_ptr new_node) BOOST_NOEXCEPT
{
bstree_algo::push_front(header, new_node);
rebalance_after_insertion(header, new_node);
}
#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_check(const_node_ptr,const KeyType&,KeyNodePtrCompare,insert_commit_data&)
template<class KeyType, class KeyNodePtrCompare>
static std::pair<node_ptr, bool> insert_unique_check
(const_node_ptr header, const KeyType &key
,KeyNodePtrCompare comp, insert_commit_data &commit_data);
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_check(const_node_ptr,node_ptr,const KeyType&,KeyNodePtrCompare,insert_commit_data&)
template<class KeyType, class KeyNodePtrCompare>
static std::pair<node_ptr, bool> insert_unique_check
(const_node_ptr header, node_ptr hint, const KeyType &key
,KeyNodePtrCompare comp, insert_commit_data &commit_data);
#endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_commit(node_ptr,node_ptr,const insert_commit_data &)
static void insert_unique_commit
(node_ptr header, node_ptr new_value, const insert_commit_data &commit_data) BOOST_NOEXCEPT
{
bstree_algo::insert_unique_commit(header, new_value, commit_data);
rebalance_after_insertion(header, new_value);
}
//! @copydoc ::boost::intrusive::bstree_algorithms::is_header
static bool is_header(const_node_ptr p) BOOST_NOEXCEPT
{ return NodeTraits::get_balance(p) == NodeTraits::zero() && bstree_algo::is_header(p); }
/// @cond
static bool verify(node_ptr header)
{
std::size_t height;
std::size_t count;
return verify_recursion(NodeTraits::get_parent(header), count, height);
}
private:
static bool verify_recursion(node_ptr n, std::size_t &count, std::size_t &height)
{
if (!n){
count = 0;
height = 0;
return true;
}
std::size_t leftcount, rightcount;
std::size_t leftheight, rightheight;
if(!verify_recursion(NodeTraits::get_left (n), leftcount, leftheight) ||
!verify_recursion(NodeTraits::get_right(n), rightcount, rightheight) ){
return false;
}
count = 1u + leftcount + rightcount;
height = 1u + (leftheight > rightheight ? leftheight : rightheight);
//If equal height, balance must be zero
if(rightheight == leftheight){
if(NodeTraits::get_balance(n) != NodeTraits::zero()){
BOOST_ASSERT(0);
return false;
}
}
//If right is taller than left, then the difference must be at least 1 and the balance positive
else if(rightheight > leftheight){
if(rightheight - leftheight > 1 ){
BOOST_ASSERT(0);
return false;
}
else if(NodeTraits::get_balance(n) != NodeTraits::positive()){
BOOST_ASSERT(0);
return false;
}
}
//If left is taller than right, then the difference must be at least 1 and the balance negative
else{
if(leftheight - rightheight > 1 ){
BOOST_ASSERT(0);
return false;
}
else if(NodeTraits::get_balance(n) != NodeTraits::negative()){
BOOST_ASSERT(0);
return false;
}
}
return true;
}
static void rebalance_after_erasure
( node_ptr header, node_ptr z, const typename bstree_algo::data_for_rebalance &info) BOOST_NOEXCEPT
{
if(info.y != z){
NodeTraits::set_balance(info.y, NodeTraits::get_balance(z));
}
//Rebalance avltree
rebalance_after_erasure_restore_invariants(header, info.x, info.x_parent);
}
static void rebalance_after_erasure_restore_invariants(node_ptr header, node_ptr x, node_ptr x_parent) BOOST_NOEXCEPT
{
for ( node_ptr root = NodeTraits::get_parent(header)
; x != root
; root = NodeTraits::get_parent(header), x_parent = NodeTraits::get_parent(x)) {
const balance x_parent_balance = NodeTraits::get_balance(x_parent);
//Don't cache x_is_leftchild or similar because x can be null and
//equal to both x_parent_left and x_parent_right
const node_ptr x_parent_left (NodeTraits::get_left(x_parent));
const node_ptr x_parent_right(NodeTraits::get_right(x_parent));
if(x_parent_balance == NodeTraits::zero()){
NodeTraits::set_balance( x_parent, x == x_parent_right ? NodeTraits::negative() : NodeTraits::positive() );
break; // the height didn't change, let's stop here
}
else if(x_parent_balance == NodeTraits::negative()){
if (x == x_parent_left) { ////x is left child or x and sibling are null
NodeTraits::set_balance(x_parent, NodeTraits::zero()); // balanced
x = x_parent;
}
else {
// x is right child (x_parent_left is the left child)
BOOST_INTRUSIVE_INVARIANT_ASSERT(x_parent_left);
if (NodeTraits::get_balance(x_parent_left) == NodeTraits::positive()) {
// x_parent_left MUST have a right child
BOOST_INTRUSIVE_INVARIANT_ASSERT(NodeTraits::get_right(x_parent_left));
x = avl_rotate_left_right(x_parent, x_parent_left, header);
}
else {
avl_rotate_right(x_parent, x_parent_left, header);
x = x_parent_left;
}
// if changed from negative to NodeTraits::positive(), no need to check above
if (NodeTraits::get_balance(x) == NodeTraits::positive()){
break;
}
}
}
else if(x_parent_balance == NodeTraits::positive()){
if (x == x_parent_right) { //x is right child or x and sibling are null
NodeTraits::set_balance(x_parent, NodeTraits::zero()); // balanced
x = x_parent;
}
else {
// x is left child (x_parent_right is the right child)
BOOST_INTRUSIVE_INVARIANT_ASSERT(x_parent_right);
if (NodeTraits::get_balance(x_parent_right) == NodeTraits::negative()) {
// x_parent_right MUST have then a left child
BOOST_INTRUSIVE_INVARIANT_ASSERT(NodeTraits::get_left(x_parent_right));
x = avl_rotate_right_left(x_parent, x_parent_right, header);
}
else {
avl_rotate_left(x_parent, x_parent_right, header);
x = x_parent_right;
}
// if changed from NodeTraits::positive() to negative, no need to check above
if (NodeTraits::get_balance(x) == NodeTraits::negative()){
break;
}
}
}
else{
BOOST_INTRUSIVE_INVARIANT_ASSERT(false); // never reached
}
}
}
static void rebalance_after_insertion(node_ptr header, node_ptr x) BOOST_NOEXCEPT
{
NodeTraits::set_balance(x, NodeTraits::zero());
// Rebalance.
for(node_ptr root = NodeTraits::get_parent(header); x != root; root = NodeTraits::get_parent(header)){
node_ptr const x_parent(NodeTraits::get_parent(x));
node_ptr const x_parent_left(NodeTraits::get_left(x_parent));
const balance x_parent_balance = NodeTraits::get_balance(x_parent);
const bool x_is_leftchild(x == x_parent_left);
if(x_parent_balance == NodeTraits::zero()){
// if x is left, parent will have parent->bal_factor = negative
// else, parent->bal_factor = NodeTraits::positive()
NodeTraits::set_balance( x_parent, x_is_leftchild ? NodeTraits::negative() : NodeTraits::positive() );
x = x_parent;
}
else if(x_parent_balance == NodeTraits::positive()){
// if x is a left child, parent->bal_factor = zero
if (x_is_leftchild)
NodeTraits::set_balance(x_parent, NodeTraits::zero());
else{ // x is a right child, needs rebalancing
if (NodeTraits::get_balance(x) == NodeTraits::negative())
avl_rotate_right_left(x_parent, x, header);
else
avl_rotate_left(x_parent, x, header);
}
break;
}
else if(x_parent_balance == NodeTraits::negative()){
// if x is a left child, needs rebalancing
if (x_is_leftchild) {
if (NodeTraits::get_balance(x) == NodeTraits::positive())
avl_rotate_left_right(x_parent, x, header);
else
avl_rotate_right(x_parent, x, header);
}
else
NodeTraits::set_balance(x_parent, NodeTraits::zero());
break;
}
else{
BOOST_INTRUSIVE_INVARIANT_ASSERT(false); // never reached
}
}
}
static void left_right_balancing(node_ptr a, node_ptr b, node_ptr c) BOOST_NOEXCEPT
{
// balancing...
const balance c_balance = NodeTraits::get_balance(c);
const balance zero_balance = NodeTraits::zero();
const balance posi_balance = NodeTraits::positive();
const balance nega_balance = NodeTraits::negative();
NodeTraits::set_balance(c, zero_balance);
if(c_balance == nega_balance){
NodeTraits::set_balance(a, posi_balance);
NodeTraits::set_balance(b, zero_balance);
}
else if(c_balance == zero_balance){
NodeTraits::set_balance(a, zero_balance);
NodeTraits::set_balance(b, zero_balance);
}
else if(c_balance == posi_balance){
NodeTraits::set_balance(a, zero_balance);
NodeTraits::set_balance(b, nega_balance);
}
else{
BOOST_INTRUSIVE_INVARIANT_ASSERT(false); // never reached
}
}
static node_ptr avl_rotate_left_right(const node_ptr a, const node_ptr a_oldleft, node_ptr hdr) BOOST_NOEXCEPT
{ // [note: 'a_oldleft' is 'b']
// | | //
// a(-2) c //
// / \ / \ //
// / \ ==> / \ //
// (pos)b [g] b a //
// / \ / \ / \ //
// [d] c [d] e f [g] //
// / \ //
// e f //
const node_ptr c = NodeTraits::get_right(a_oldleft);
bstree_algo::rotate_left_no_parent_fix(a_oldleft, c);
//No need to link c with a [NodeTraits::set_parent(c, a) + NodeTraits::set_left(a, c)]
//as c is not root and another rotation is coming
bstree_algo::rotate_right(a, c, NodeTraits::get_parent(a), hdr);
left_right_balancing(a, a_oldleft, c);
return c;
}
static node_ptr avl_rotate_right_left(const node_ptr a, const node_ptr a_oldright, node_ptr hdr) BOOST_NOEXCEPT
{ // [note: 'a_oldright' is 'b']
// | | //
// a(pos) c //
// / \ / \ //
// / \ / \ //
// [d] b(neg) ==> a b //
// / \ / \ / \ //
// c [g] [d] e f [g] //
// / \ //
// e f //
const node_ptr c (NodeTraits::get_left(a_oldright));
bstree_algo::rotate_right_no_parent_fix(a_oldright, c);
//No need to link c with a [NodeTraits::set_parent(c, a) + NodeTraits::set_right(a, c)]
//as c is not root and another rotation is coming.
bstree_algo::rotate_left(a, c, NodeTraits::get_parent(a), hdr);
left_right_balancing(a_oldright, a, c);
return c;
}
static void avl_rotate_left(node_ptr x, node_ptr x_oldright, node_ptr hdr) BOOST_NOEXCEPT
{
bstree_algo::rotate_left(x, x_oldright, NodeTraits::get_parent(x), hdr);
// reset the balancing factor
if (NodeTraits::get_balance(x_oldright) == NodeTraits::positive()) {
NodeTraits::set_balance(x, NodeTraits::zero());
NodeTraits::set_balance(x_oldright, NodeTraits::zero());
}
else { // this doesn't happen during insertions
NodeTraits::set_balance(x, NodeTraits::positive());
NodeTraits::set_balance(x_oldright, NodeTraits::negative());
}
}
static void avl_rotate_right(node_ptr x, node_ptr x_oldleft, node_ptr hdr) BOOST_NOEXCEPT
{
bstree_algo::rotate_right(x, x_oldleft, NodeTraits::get_parent(x), hdr);
// reset the balancing factor
if (NodeTraits::get_balance(x_oldleft) == NodeTraits::negative()) {
NodeTraits::set_balance(x, NodeTraits::zero());
NodeTraits::set_balance(x_oldleft, NodeTraits::zero());
}
else { // this doesn't happen during insertions
NodeTraits::set_balance(x, NodeTraits::negative());
NodeTraits::set_balance(x_oldleft, NodeTraits::positive());
}
}
/// @endcond
};
/// @cond
template<class NodeTraits>
struct get_algo<AvlTreeAlgorithms, NodeTraits>
{
typedef avltree_algorithms<NodeTraits> type;
};
template <class ValueTraits, class NodePtrCompare, class ExtraChecker>
struct get_node_checker<AvlTreeAlgorithms, ValueTraits, NodePtrCompare, ExtraChecker>
{
typedef detail::avltree_node_checker<ValueTraits, NodePtrCompare, ExtraChecker> type;
};
/// @endcond
} //namespace intrusive
} //namespace boost
#include <boost/intrusive/detail/config_end.hpp>
#endif //BOOST_INTRUSIVE_AVLTREE_ALGORITHMS_HPP