421 lines
18 KiB
Plaintext
421 lines
18 KiB
Plaintext
/////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// (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.
|
|
//
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Scapegoat tree algorithms are taken from the paper titled:
|
|
// "Scapegoat Trees" by Igal Galperin Ronald L. Rivest.
|
|
//
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
#ifndef BOOST_INTRUSIVE_SGTREE_ALGORITHMS_HPP
|
|
#define BOOST_INTRUSIVE_SGTREE_ALGORITHMS_HPP
|
|
|
|
#include <boost/intrusive/detail/config_begin.hpp>
|
|
#include <boost/intrusive/intrusive_fwd.hpp>
|
|
|
|
#include <cstddef>
|
|
#include <boost/intrusive/detail/algo_type.hpp>
|
|
#include <boost/intrusive/bstree_algorithms.hpp>
|
|
|
|
#if defined(BOOST_HAS_PRAGMA_ONCE)
|
|
# pragma once
|
|
#endif
|
|
|
|
namespace boost {
|
|
namespace intrusive {
|
|
|
|
//! sgtree_algorithms is configured with a NodeTraits class, which encapsulates the
|
|
//! information about the node to be manipulated. NodeTraits must support the
|
|
//! following interface:
|
|
//!
|
|
//! <b>Typedefs</b>:
|
|
//!
|
|
//! <tt>node</tt>: The type of the node that forms the binary search tree
|
|
//!
|
|
//! <tt>node_ptr</tt>: A pointer to a node
|
|
//!
|
|
//! <tt>const_node_ptr</tt>: A pointer to a const node
|
|
//!
|
|
//! <b>Static functions</b>:
|
|
//!
|
|
//! <tt>static node_ptr get_parent(const_node_ptr n);</tt>
|
|
//!
|
|
//! <tt>static void set_parent(node_ptr n, node_ptr parent);</tt>
|
|
//!
|
|
//! <tt>static node_ptr get_left(const_node_ptr n);</tt>
|
|
//!
|
|
//! <tt>static void set_left(node_ptr n, node_ptr left);</tt>
|
|
//!
|
|
//! <tt>static node_ptr get_right(const_node_ptr n);</tt>
|
|
//!
|
|
//! <tt>static void set_right(node_ptr n, node_ptr right);</tt>
|
|
template<class NodeTraits>
|
|
class sgtree_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;
|
|
|
|
/// @cond
|
|
private:
|
|
|
|
typedef bstree_algorithms<NodeTraits> bstree_algo;
|
|
|
|
/// @endcond
|
|
|
|
public:
|
|
//! This type is the information that will be
|
|
//! filled by insert_unique_check
|
|
struct insert_commit_data
|
|
: bstree_algo::insert_commit_data
|
|
{
|
|
std::size_t depth;
|
|
};
|
|
|
|
#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::get_header(const const_node_ptr&)
|
|
static node_ptr get_header(const const_node_ptr & n);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::begin_node
|
|
static node_ptr begin_node(const const_node_ptr & header);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::end_node
|
|
static node_ptr end_node(const const_node_ptr & header);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::swap_tree
|
|
static void swap_tree(const node_ptr & header1, const node_ptr & header2);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(const node_ptr&,const node_ptr&)
|
|
static void swap_nodes(const node_ptr & node1, const node_ptr & node2);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(const node_ptr&,const node_ptr&,const node_ptr&,const node_ptr&)
|
|
static void swap_nodes(const node_ptr & node1, const node_ptr & header1, const node_ptr & node2, const node_ptr & header2);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(const node_ptr&,const node_ptr&)
|
|
static void replace_node(const node_ptr & node_to_be_replaced, const node_ptr & new_node);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(const node_ptr&,const node_ptr&,const node_ptr&)
|
|
static void replace_node(const node_ptr & node_to_be_replaced, const node_ptr & header, const node_ptr & new_node);
|
|
|
|
//Unlink is not possible since tree metadata is needed to update the tree
|
|
//!static void unlink(const node_ptr & node);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::unlink_leftmost_without_rebalance
|
|
static node_ptr unlink_leftmost_without_rebalance(const node_ptr & header);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::unique(const const_node_ptr&)
|
|
static bool unique(const const_node_ptr & node);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::size(const const_node_ptr&)
|
|
static std::size_t size(const const_node_ptr & header);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::next_node(const node_ptr&)
|
|
static node_ptr next_node(const node_ptr & node);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::prev_node(const node_ptr&)
|
|
static node_ptr prev_node(const node_ptr & node);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::init(const node_ptr&)
|
|
static void init(const node_ptr & node);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::init_header(const node_ptr&)
|
|
static void init_header(const node_ptr & header);
|
|
#endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::erase(const node_ptr&,const node_ptr&)
|
|
template<class AlphaByMaxSize>
|
|
static node_ptr erase(const node_ptr & header, const node_ptr & z, std::size_t tree_size, std::size_t &max_tree_size, AlphaByMaxSize alpha_by_maxsize)
|
|
{
|
|
bstree_algo::erase(header, z);
|
|
--tree_size;
|
|
if (tree_size > 0 &&
|
|
tree_size < alpha_by_maxsize(max_tree_size)){
|
|
bstree_algo::rebalance(header);
|
|
max_tree_size = tree_size;
|
|
}
|
|
return z;
|
|
}
|
|
|
|
#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::clone(const const_node_ptr&,const node_ptr&,Cloner,Disposer)
|
|
template <class Cloner, class Disposer>
|
|
static void clone
|
|
(const const_node_ptr & source_header, const node_ptr & target_header, Cloner cloner, Disposer disposer);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::clear_and_dispose(const node_ptr&,Disposer)
|
|
template<class Disposer>
|
|
static void clear_and_dispose(const node_ptr & header, Disposer disposer);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
|
|
template<class KeyType, class KeyNodePtrCompare>
|
|
static node_ptr lower_bound
|
|
(const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::upper_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
|
|
template<class KeyType, class KeyNodePtrCompare>
|
|
static node_ptr upper_bound
|
|
(const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::find(const const_node_ptr&, const KeyType&,KeyNodePtrCompare)
|
|
template<class KeyType, class KeyNodePtrCompare>
|
|
static node_ptr find
|
|
(const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::equal_range(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
|
|
template<class KeyType, class KeyNodePtrCompare>
|
|
static std::pair<node_ptr, node_ptr> equal_range
|
|
(const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::bounded_range(const 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 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 const_node_ptr&,const KeyType&,KeyNodePtrCompare)
|
|
template<class KeyType, class KeyNodePtrCompare>
|
|
static std::size_t count(const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
|
|
|
|
#endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal_upper_bound(const node_ptr&,const node_ptr&,NodePtrCompare)
|
|
template<class NodePtrCompare, class H_Alpha>
|
|
static node_ptr insert_equal_upper_bound
|
|
(const node_ptr & h, const node_ptr & new_node, NodePtrCompare comp
|
|
,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
|
|
{
|
|
std::size_t depth;
|
|
bstree_algo::insert_equal_upper_bound(h, new_node, comp, &depth);
|
|
rebalance_after_insertion(new_node, depth, tree_size+1, h_alpha, max_tree_size);
|
|
return new_node;
|
|
}
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal_lower_bound(const node_ptr&,const node_ptr&,NodePtrCompare)
|
|
template<class NodePtrCompare, class H_Alpha>
|
|
static node_ptr insert_equal_lower_bound
|
|
(const node_ptr & h, const node_ptr & new_node, NodePtrCompare comp
|
|
,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
|
|
{
|
|
std::size_t depth;
|
|
bstree_algo::insert_equal_lower_bound(h, new_node, comp, &depth);
|
|
rebalance_after_insertion(new_node, depth, tree_size+1, h_alpha, max_tree_size);
|
|
return new_node;
|
|
}
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal(const node_ptr&,const node_ptr&,const node_ptr&,NodePtrCompare)
|
|
template<class NodePtrCompare, class H_Alpha>
|
|
static node_ptr insert_equal
|
|
(const node_ptr & header, const node_ptr & hint, const node_ptr & new_node, NodePtrCompare comp
|
|
,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
|
|
{
|
|
std::size_t depth;
|
|
bstree_algo::insert_equal(header, hint, new_node, comp, &depth);
|
|
rebalance_after_insertion(new_node, depth, tree_size+1, h_alpha, max_tree_size);
|
|
return new_node;
|
|
}
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_before(const node_ptr&,const node_ptr&,const node_ptr&)
|
|
template<class H_Alpha>
|
|
static node_ptr insert_before
|
|
(const node_ptr & header, const node_ptr & pos, const node_ptr & new_node
|
|
,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
|
|
{
|
|
std::size_t depth;
|
|
bstree_algo::insert_before(header, pos, new_node, &depth);
|
|
rebalance_after_insertion(new_node, depth, tree_size+1, h_alpha, max_tree_size);
|
|
return new_node;
|
|
}
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::push_back(const node_ptr&,const node_ptr&)
|
|
template<class H_Alpha>
|
|
static void push_back(const node_ptr & header, const node_ptr & new_node
|
|
,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
|
|
{
|
|
std::size_t depth;
|
|
bstree_algo::push_back(header, new_node, &depth);
|
|
rebalance_after_insertion(new_node, depth, tree_size+1, h_alpha, max_tree_size);
|
|
}
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::push_front(const node_ptr&,const node_ptr&)
|
|
template<class H_Alpha>
|
|
static void push_front(const node_ptr & header, const node_ptr & new_node
|
|
,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
|
|
{
|
|
std::size_t depth;
|
|
bstree_algo::push_front(header, new_node, &depth);
|
|
rebalance_after_insertion(new_node, depth, tree_size+1, h_alpha, max_tree_size);
|
|
}
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_check(const const_node_ptr&,const KeyType&,KeyNodePtrCompare,insert_commit_data&)
|
|
template<class KeyType, class KeyNodePtrCompare>
|
|
static std::pair<node_ptr, bool> insert_unique_check
|
|
(const const_node_ptr & header, const KeyType &key
|
|
,KeyNodePtrCompare comp, insert_commit_data &commit_data)
|
|
{
|
|
std::size_t depth;
|
|
std::pair<node_ptr, bool> ret =
|
|
bstree_algo::insert_unique_check(header, key, comp, commit_data, &depth);
|
|
commit_data.depth = depth;
|
|
return ret;
|
|
}
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_check(const const_node_ptr&,const node_ptr&,const KeyType&,KeyNodePtrCompare,insert_commit_data&)
|
|
template<class KeyType, class KeyNodePtrCompare>
|
|
static std::pair<node_ptr, bool> insert_unique_check
|
|
(const const_node_ptr & header, const node_ptr &hint, const KeyType &key
|
|
,KeyNodePtrCompare comp, insert_commit_data &commit_data)
|
|
{
|
|
std::size_t depth;
|
|
std::pair<node_ptr, bool> ret =
|
|
bstree_algo::insert_unique_check
|
|
(header, hint, key, comp, commit_data, &depth);
|
|
commit_data.depth = depth;
|
|
return ret;
|
|
}
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_commit(const node_ptr&,const node_ptr&,const insert_commit_data&)
|
|
template<class H_Alpha>
|
|
BOOST_INTRUSIVE_FORCEINLINE static void insert_unique_commit
|
|
(const node_ptr & header, const node_ptr & new_value, const insert_commit_data &commit_data
|
|
,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
|
|
{ return insert_commit(header, new_value, commit_data, tree_size, h_alpha, max_tree_size); }
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::transfer_unique
|
|
template<class NodePtrCompare, class H_Alpha, class AlphaByMaxSize>
|
|
static bool transfer_unique
|
|
( const node_ptr & header1, NodePtrCompare comp, std::size_t tree1_size, std::size_t &max_tree1_size
|
|
, const node_ptr &header2, const node_ptr & z, std::size_t tree2_size, std::size_t &max_tree2_size
|
|
,H_Alpha h_alpha, AlphaByMaxSize alpha_by_maxsize)
|
|
{
|
|
insert_commit_data commit_data;
|
|
bool const transferable = insert_unique_check(header1, z, comp, commit_data).second;
|
|
if(transferable){
|
|
erase(header2, z, tree2_size, max_tree2_size, alpha_by_maxsize);
|
|
insert_commit(header1, z, commit_data, tree1_size, h_alpha, max_tree1_size);
|
|
}
|
|
return transferable;
|
|
}
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::transfer_equal
|
|
template<class NodePtrCompare, class H_Alpha, class AlphaByMaxSize>
|
|
static void transfer_equal
|
|
( const node_ptr & header1, NodePtrCompare comp, std::size_t tree1_size, std::size_t &max_tree1_size
|
|
, const node_ptr &header2, const node_ptr & z, std::size_t tree2_size, std::size_t &max_tree2_size
|
|
,H_Alpha h_alpha, AlphaByMaxSize alpha_by_maxsize)
|
|
{
|
|
insert_commit_data commit_data;
|
|
insert_equal_upper_bound_check(header1, z, comp, commit_data);
|
|
erase(header2, z, tree2_size, max_tree2_size, alpha_by_maxsize);
|
|
insert_commit(header1, z, commit_data, tree1_size, h_alpha, max_tree1_size);
|
|
}
|
|
|
|
#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::is_header
|
|
static bool is_header(const const_node_ptr & p);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::is_header
|
|
static void rebalance(const node_ptr & header);
|
|
|
|
//! @copydoc ::boost::intrusive::bstree_algorithms::rebalance_subtree
|
|
static node_ptr rebalance_subtree(const node_ptr & old_root)
|
|
#endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
|
|
|
|
/// @cond
|
|
private:
|
|
|
|
template<class KeyType, class KeyNodePtrCompare>
|
|
static void insert_equal_upper_bound_check
|
|
(const node_ptr & header, const KeyType &key
|
|
,KeyNodePtrCompare comp, insert_commit_data &commit_data)
|
|
{
|
|
std::size_t depth;
|
|
bstree_algo::insert_equal_upper_bound_check(header, key, comp, commit_data, &depth);
|
|
commit_data.depth = depth;
|
|
}
|
|
|
|
template<class H_Alpha>
|
|
static void insert_commit
|
|
(const node_ptr & header, const node_ptr & new_value, const insert_commit_data &commit_data
|
|
,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
|
|
{
|
|
bstree_algo::insert_unique_commit(header, new_value, commit_data);
|
|
rebalance_after_insertion(new_value, commit_data.depth, tree_size+1, h_alpha, max_tree_size);
|
|
}
|
|
|
|
template<class H_Alpha>
|
|
static void rebalance_after_insertion
|
|
(const node_ptr &x, std::size_t depth
|
|
, std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
|
|
{
|
|
if(tree_size > max_tree_size)
|
|
max_tree_size = tree_size;
|
|
|
|
if(tree_size > 2 && //Nothing to do with only the root
|
|
//Check if the root node is unbalanced
|
|
//Scapegoat paper depth counts root depth as zero and "depth" counts root as 1,
|
|
//but since "depth" is the depth of the ancestor of x, i == depth
|
|
depth > h_alpha(tree_size)){
|
|
|
|
//Find the first non height-balanced node
|
|
//as described in the section 4.2 of the paper.
|
|
//This method is the alternative method described
|
|
//in the paper. Authors claim that this method
|
|
//may tend to yield more balanced trees on the average
|
|
//than the weight balanced method.
|
|
node_ptr s = x;
|
|
std::size_t size = 1;
|
|
for(std::size_t ancestor = 1; ancestor != depth; ++ancestor){
|
|
const node_ptr s_parent = NodeTraits::get_parent(s);
|
|
const node_ptr s_parent_left = NodeTraits::get_left(s_parent);
|
|
//Obtain parent's size (previous size + parent + sibling tree)
|
|
const node_ptr s_sibling = s_parent_left == s ? NodeTraits::get_right(s_parent) : s_parent_left;
|
|
size += 1 + bstree_algo::subtree_size(s_sibling);
|
|
s = s_parent;
|
|
if(ancestor > h_alpha(size)){ //is 's' scapegoat?
|
|
bstree_algo::rebalance_subtree(s);
|
|
return;
|
|
}
|
|
}
|
|
//The whole tree must be rebuilt
|
|
max_tree_size = tree_size;
|
|
bstree_algo::rebalance_subtree(NodeTraits::get_parent(s));
|
|
}
|
|
}
|
|
/// @endcond
|
|
};
|
|
|
|
/// @cond
|
|
|
|
template<class NodeTraits>
|
|
struct get_algo<SgTreeAlgorithms, NodeTraits>
|
|
{
|
|
typedef sgtree_algorithms<NodeTraits> type;
|
|
};
|
|
|
|
template <class ValueTraits, class NodePtrCompare, class ExtraChecker>
|
|
struct get_node_checker<SgTreeAlgorithms, ValueTraits, NodePtrCompare, ExtraChecker>
|
|
{
|
|
typedef detail::bstree_node_checker<ValueTraits, NodePtrCompare, ExtraChecker> type;
|
|
};
|
|
|
|
/// @endcond
|
|
|
|
} //namespace intrusive
|
|
} //namespace boost
|
|
|
|
#include <boost/intrusive/detail/config_end.hpp>
|
|
|
|
#endif //BOOST_INTRUSIVE_SGTREE_ALGORITHMS_HPP
|