annotate DEPENDENCIES/generic/include/boost/intrusive/sgtree_algorithms.hpp @ 133:4acb5d8d80b6 tip

Don't fail environmental check if README.md exists (but .txt and no-suffix don't)
author Chris Cannam
date Tue, 30 Jul 2019 12:25:44 +0100
parents c530137014c0
children
rev   line source
Chris@16 1 /////////////////////////////////////////////////////////////////////////////
Chris@16 2 //
Chris@101 3 // (C) Copyright Ion Gaztanaga 2007-2014
Chris@16 4 //
Chris@16 5 // Distributed under the Boost Software License, Version 1.0.
Chris@16 6 // (See accompanying file LICENSE_1_0.txt or copy at
Chris@16 7 // http://www.boost.org/LICENSE_1_0.txt)
Chris@16 8 //
Chris@16 9 // See http://www.boost.org/libs/intrusive for documentation.
Chris@16 10 //
Chris@16 11 /////////////////////////////////////////////////////////////////////////////
Chris@16 12 //
Chris@16 13 // Scapegoat tree algorithms are taken from the paper titled:
Chris@16 14 // "Scapegoat Trees" by Igal Galperin Ronald L. Rivest.
Chris@16 15 //
Chris@16 16 /////////////////////////////////////////////////////////////////////////////
Chris@16 17 #ifndef BOOST_INTRUSIVE_SGTREE_ALGORITHMS_HPP
Chris@16 18 #define BOOST_INTRUSIVE_SGTREE_ALGORITHMS_HPP
Chris@16 19
Chris@16 20 #include <boost/intrusive/detail/config_begin.hpp>
Chris@101 21 #include <boost/intrusive/intrusive_fwd.hpp>
Chris@16 22
Chris@16 23 #include <cstddef>
Chris@101 24 #include <boost/intrusive/detail/algo_type.hpp>
Chris@16 25 #include <boost/intrusive/bstree_algorithms.hpp>
Chris@16 26
Chris@101 27 #if defined(BOOST_HAS_PRAGMA_ONCE)
Chris@101 28 # pragma once
Chris@101 29 #endif
Chris@16 30
Chris@16 31 namespace boost {
Chris@16 32 namespace intrusive {
Chris@16 33
Chris@16 34 //! sgtree_algorithms is configured with a NodeTraits class, which encapsulates the
Chris@16 35 //! information about the node to be manipulated. NodeTraits must support the
Chris@16 36 //! following interface:
Chris@16 37 //!
Chris@16 38 //! <b>Typedefs</b>:
Chris@16 39 //!
Chris@16 40 //! <tt>node</tt>: The type of the node that forms the binary search tree
Chris@16 41 //!
Chris@16 42 //! <tt>node_ptr</tt>: A pointer to a node
Chris@16 43 //!
Chris@16 44 //! <tt>const_node_ptr</tt>: A pointer to a const node
Chris@16 45 //!
Chris@16 46 //! <b>Static functions</b>:
Chris@16 47 //!
Chris@16 48 //! <tt>static node_ptr get_parent(const_node_ptr n);</tt>
Chris@16 49 //!
Chris@16 50 //! <tt>static void set_parent(node_ptr n, node_ptr parent);</tt>
Chris@16 51 //!
Chris@16 52 //! <tt>static node_ptr get_left(const_node_ptr n);</tt>
Chris@16 53 //!
Chris@16 54 //! <tt>static void set_left(node_ptr n, node_ptr left);</tt>
Chris@16 55 //!
Chris@16 56 //! <tt>static node_ptr get_right(const_node_ptr n);</tt>
Chris@16 57 //!
Chris@16 58 //! <tt>static void set_right(node_ptr n, node_ptr right);</tt>
Chris@16 59 template<class NodeTraits>
Chris@16 60 class sgtree_algorithms
Chris@16 61 #ifndef BOOST_INTRUSIVE_DOXYGEN_INVOKED
Chris@16 62 : public bstree_algorithms<NodeTraits>
Chris@16 63 #endif
Chris@16 64 {
Chris@16 65 public:
Chris@16 66 typedef typename NodeTraits::node node;
Chris@16 67 typedef NodeTraits node_traits;
Chris@16 68 typedef typename NodeTraits::node_ptr node_ptr;
Chris@16 69 typedef typename NodeTraits::const_node_ptr const_node_ptr;
Chris@16 70
Chris@16 71 /// @cond
Chris@16 72 private:
Chris@16 73
Chris@16 74 typedef bstree_algorithms<NodeTraits> bstree_algo;
Chris@16 75
Chris@16 76 /// @endcond
Chris@16 77
Chris@16 78 public:
Chris@16 79 //! This type is the information that will be
Chris@16 80 //! filled by insert_unique_check
Chris@16 81 struct insert_commit_data
Chris@16 82 : bstree_algo::insert_commit_data
Chris@16 83 {
Chris@16 84 std::size_t depth;
Chris@16 85 };
Chris@16 86
Chris@16 87 #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
Chris@16 88 //! @copydoc ::boost::intrusive::bstree_algorithms::get_header(const const_node_ptr&)
Chris@16 89 static node_ptr get_header(const const_node_ptr & n);
Chris@16 90
Chris@16 91 //! @copydoc ::boost::intrusive::bstree_algorithms::begin_node
Chris@16 92 static node_ptr begin_node(const const_node_ptr & header);
Chris@16 93
Chris@16 94 //! @copydoc ::boost::intrusive::bstree_algorithms::end_node
Chris@16 95 static node_ptr end_node(const const_node_ptr & header);
Chris@16 96
Chris@16 97 //! @copydoc ::boost::intrusive::bstree_algorithms::swap_tree
Chris@16 98 static void swap_tree(const node_ptr & header1, const node_ptr & header2);
Chris@16 99
Chris@16 100 //! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(const node_ptr&,const node_ptr&)
Chris@16 101 static void swap_nodes(const node_ptr & node1, const node_ptr & node2);
Chris@16 102
Chris@16 103 //! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(const node_ptr&,const node_ptr&,const node_ptr&,const node_ptr&)
Chris@16 104 static void swap_nodes(const node_ptr & node1, const node_ptr & header1, const node_ptr & node2, const node_ptr & header2);
Chris@16 105
Chris@16 106 //! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(const node_ptr&,const node_ptr&)
Chris@16 107 static void replace_node(const node_ptr & node_to_be_replaced, const node_ptr & new_node);
Chris@16 108
Chris@16 109 //! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(const node_ptr&,const node_ptr&,const node_ptr&)
Chris@16 110 static void replace_node(const node_ptr & node_to_be_replaced, const node_ptr & header, const node_ptr & new_node);
Chris@16 111
Chris@16 112 //Unlink is not possible since tree metadata is needed to update the tree
Chris@16 113 //!static void unlink(const node_ptr & node);
Chris@16 114
Chris@16 115 //! @copydoc ::boost::intrusive::bstree_algorithms::unlink_leftmost_without_rebalance
Chris@16 116 static node_ptr unlink_leftmost_without_rebalance(const node_ptr & header);
Chris@16 117
Chris@16 118 //! @copydoc ::boost::intrusive::bstree_algorithms::unique(const const_node_ptr&)
Chris@16 119 static bool unique(const const_node_ptr & node);
Chris@16 120
Chris@16 121 //! @copydoc ::boost::intrusive::bstree_algorithms::size(const const_node_ptr&)
Chris@16 122 static std::size_t size(const const_node_ptr & header);
Chris@16 123
Chris@16 124 //! @copydoc ::boost::intrusive::bstree_algorithms::next_node(const node_ptr&)
Chris@16 125 static node_ptr next_node(const node_ptr & node);
Chris@16 126
Chris@16 127 //! @copydoc ::boost::intrusive::bstree_algorithms::prev_node(const node_ptr&)
Chris@16 128 static node_ptr prev_node(const node_ptr & node);
Chris@16 129
Chris@16 130 //! @copydoc ::boost::intrusive::bstree_algorithms::init(const node_ptr&)
Chris@16 131 static void init(const node_ptr & node);
Chris@16 132
Chris@16 133 //! @copydoc ::boost::intrusive::bstree_algorithms::init_header(const node_ptr&)
Chris@16 134 static void init_header(const node_ptr & header);
Chris@16 135 #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
Chris@16 136
Chris@16 137 //! @copydoc ::boost::intrusive::bstree_algorithms::erase(const node_ptr&,const node_ptr&)
Chris@16 138 template<class AlphaByMaxSize>
Chris@16 139 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)
Chris@16 140 {
Chris@16 141 //typename bstree_algo::data_for_rebalance info;
Chris@16 142 bstree_algo::erase(header, z);
Chris@16 143 --tree_size;
Chris@16 144 if (tree_size > 0 &&
Chris@16 145 tree_size < alpha_by_maxsize(max_tree_size)){
Chris@16 146 bstree_algo::rebalance(header);
Chris@16 147 max_tree_size = tree_size;
Chris@16 148 }
Chris@16 149 return z;
Chris@16 150 }
Chris@16 151
Chris@16 152 #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
Chris@16 153 //! @copydoc ::boost::intrusive::bstree_algorithms::clone(const const_node_ptr&,const node_ptr&,Cloner,Disposer)
Chris@16 154 template <class Cloner, class Disposer>
Chris@16 155 static void clone
Chris@16 156 (const const_node_ptr & source_header, const node_ptr & target_header, Cloner cloner, Disposer disposer);
Chris@16 157
Chris@16 158 //! @copydoc ::boost::intrusive::bstree_algorithms::clear_and_dispose(const node_ptr&,Disposer)
Chris@16 159 template<class Disposer>
Chris@16 160 static void clear_and_dispose(const node_ptr & header, Disposer disposer);
Chris@16 161
Chris@16 162 //! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
Chris@16 163 template<class KeyType, class KeyNodePtrCompare>
Chris@16 164 static node_ptr lower_bound
Chris@16 165 (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
Chris@16 166
Chris@16 167 //! @copydoc ::boost::intrusive::bstree_algorithms::upper_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
Chris@16 168 template<class KeyType, class KeyNodePtrCompare>
Chris@16 169 static node_ptr upper_bound
Chris@16 170 (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
Chris@16 171
Chris@16 172 //! @copydoc ::boost::intrusive::bstree_algorithms::find(const const_node_ptr&, const KeyType&,KeyNodePtrCompare)
Chris@16 173 template<class KeyType, class KeyNodePtrCompare>
Chris@16 174 static node_ptr find
Chris@16 175 (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
Chris@16 176
Chris@16 177 //! @copydoc ::boost::intrusive::bstree_algorithms::equal_range(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
Chris@16 178 template<class KeyType, class KeyNodePtrCompare>
Chris@16 179 static std::pair<node_ptr, node_ptr> equal_range
Chris@16 180 (const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
Chris@16 181
Chris@16 182 //! @copydoc ::boost::intrusive::bstree_algorithms::bounded_range(const const_node_ptr&,const KeyType&,const KeyType&,KeyNodePtrCompare,bool,bool)
Chris@16 183 template<class KeyType, class KeyNodePtrCompare>
Chris@16 184 static std::pair<node_ptr, node_ptr> bounded_range
Chris@16 185 (const const_node_ptr & header, const KeyType &lower_key, const KeyType &upper_key, KeyNodePtrCompare comp
Chris@16 186 , bool left_closed, bool right_closed);
Chris@16 187
Chris@16 188 //! @copydoc ::boost::intrusive::bstree_algorithms::count(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
Chris@16 189 template<class KeyType, class KeyNodePtrCompare>
Chris@16 190 static std::size_t count(const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
Chris@101 191
Chris@16 192 #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
Chris@16 193
Chris@16 194 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal_upper_bound(const node_ptr&,const node_ptr&,NodePtrCompare)
Chris@16 195 template<class NodePtrCompare, class H_Alpha>
Chris@16 196 static node_ptr insert_equal_upper_bound
Chris@16 197 (const node_ptr & h, const node_ptr & new_node, NodePtrCompare comp
Chris@16 198 ,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
Chris@16 199 {
Chris@16 200 std::size_t depth;
Chris@16 201 bstree_algo::insert_equal_upper_bound(h, new_node, comp, &depth);
Chris@16 202 rebalance_after_insertion(new_node, depth, tree_size+1, h_alpha, max_tree_size);
Chris@16 203 return new_node;
Chris@16 204 }
Chris@16 205
Chris@16 206 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal_lower_bound(const node_ptr&,const node_ptr&,NodePtrCompare)
Chris@16 207 template<class NodePtrCompare, class H_Alpha>
Chris@16 208 static node_ptr insert_equal_lower_bound
Chris@16 209 (const node_ptr & h, const node_ptr & new_node, NodePtrCompare comp
Chris@16 210 ,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
Chris@16 211 {
Chris@16 212 std::size_t depth;
Chris@16 213 bstree_algo::insert_equal_lower_bound(h, new_node, comp, &depth);
Chris@16 214 rebalance_after_insertion(new_node, depth, tree_size+1, h_alpha, max_tree_size);
Chris@16 215 return new_node;
Chris@16 216 }
Chris@16 217
Chris@16 218 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal(const node_ptr&,const node_ptr&,const node_ptr&,NodePtrCompare)
Chris@16 219 template<class NodePtrCompare, class H_Alpha>
Chris@16 220 static node_ptr insert_equal
Chris@16 221 (const node_ptr & header, const node_ptr & hint, const node_ptr & new_node, NodePtrCompare comp
Chris@16 222 ,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
Chris@16 223 {
Chris@16 224 std::size_t depth;
Chris@16 225 bstree_algo::insert_equal(header, hint, new_node, comp, &depth);
Chris@16 226 rebalance_after_insertion(new_node, depth, tree_size+1, h_alpha, max_tree_size);
Chris@16 227 return new_node;
Chris@16 228 }
Chris@16 229
Chris@16 230 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_before(const node_ptr&,const node_ptr&,const node_ptr&)
Chris@16 231 template<class H_Alpha>
Chris@16 232 static node_ptr insert_before
Chris@16 233 (const node_ptr & header, const node_ptr & pos, const node_ptr & new_node
Chris@16 234 ,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
Chris@16 235 {
Chris@16 236 std::size_t depth;
Chris@16 237 bstree_algo::insert_before(header, pos, new_node, &depth);
Chris@16 238 rebalance_after_insertion(new_node, depth, tree_size+1, h_alpha, max_tree_size);
Chris@16 239 return new_node;
Chris@16 240 }
Chris@16 241
Chris@16 242 //! @copydoc ::boost::intrusive::bstree_algorithms::push_back(const node_ptr&,const node_ptr&)
Chris@16 243 template<class H_Alpha>
Chris@16 244 static void push_back(const node_ptr & header, const node_ptr & new_node
Chris@16 245 ,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
Chris@16 246 {
Chris@16 247 std::size_t depth;
Chris@16 248 bstree_algo::push_back(header, new_node, &depth);
Chris@16 249 rebalance_after_insertion(new_node, depth, tree_size+1, h_alpha, max_tree_size);
Chris@16 250 }
Chris@16 251
Chris@16 252 //! @copydoc ::boost::intrusive::bstree_algorithms::push_front(const node_ptr&,const node_ptr&)
Chris@16 253 template<class H_Alpha>
Chris@16 254 static void push_front(const node_ptr & header, const node_ptr & new_node
Chris@16 255 ,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
Chris@16 256 {
Chris@16 257 std::size_t depth;
Chris@16 258 bstree_algo::push_front(header, new_node, &depth);
Chris@16 259 rebalance_after_insertion(new_node, depth, tree_size+1, h_alpha, max_tree_size);
Chris@16 260 }
Chris@16 261
Chris@16 262 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_check(const const_node_ptr&,const KeyType&,KeyNodePtrCompare,insert_commit_data&)
Chris@16 263 template<class KeyType, class KeyNodePtrCompare>
Chris@16 264 static std::pair<node_ptr, bool> insert_unique_check
Chris@16 265 (const const_node_ptr & header, const KeyType &key
Chris@16 266 ,KeyNodePtrCompare comp, insert_commit_data &commit_data)
Chris@16 267 {
Chris@16 268 std::size_t depth;
Chris@16 269 std::pair<node_ptr, bool> ret =
Chris@16 270 bstree_algo::insert_unique_check(header, key, comp, commit_data, &depth);
Chris@16 271 commit_data.depth = depth;
Chris@16 272 return ret;
Chris@16 273 }
Chris@16 274
Chris@16 275 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_check(const const_node_ptr&,const node_ptr&,const KeyType&,KeyNodePtrCompare,insert_commit_data&)
Chris@16 276 template<class KeyType, class KeyNodePtrCompare>
Chris@16 277 static std::pair<node_ptr, bool> insert_unique_check
Chris@16 278 (const const_node_ptr & header, const node_ptr &hint, const KeyType &key
Chris@16 279 ,KeyNodePtrCompare comp, insert_commit_data &commit_data)
Chris@16 280 {
Chris@16 281 std::size_t depth;
Chris@16 282 std::pair<node_ptr, bool> ret =
Chris@16 283 bstree_algo::insert_unique_check
Chris@16 284 (header, hint, key, comp, commit_data, &depth);
Chris@16 285 commit_data.depth = depth;
Chris@16 286 return ret;
Chris@16 287 }
Chris@16 288
Chris@16 289 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_commit(const node_ptr&,const node_ptr&,const insert_commit_data&)
Chris@16 290 template<class H_Alpha>
Chris@16 291 static void insert_unique_commit
Chris@16 292 (const node_ptr & header, const node_ptr & new_value, const insert_commit_data &commit_data
Chris@16 293 ,std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
Chris@16 294 {
Chris@16 295 bstree_algo::insert_unique_commit(header, new_value, commit_data);
Chris@16 296 rebalance_after_insertion(new_value, commit_data.depth, tree_size+1, h_alpha, max_tree_size);
Chris@16 297 }
Chris@16 298
Chris@16 299 #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
Chris@16 300 //! @copydoc ::boost::intrusive::bstree_algorithms::is_header
Chris@16 301 static bool is_header(const const_node_ptr & p);
Chris@16 302
Chris@16 303 //! @copydoc ::boost::intrusive::bstree_algorithms::is_header
Chris@16 304 static void rebalance(const node_ptr & header);
Chris@16 305
Chris@16 306 //! @copydoc ::boost::intrusive::bstree_algorithms::rebalance_subtree
Chris@16 307 static node_ptr rebalance_subtree(const node_ptr & old_root)
Chris@16 308 #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
Chris@16 309
Chris@16 310 /// @cond
Chris@16 311 private:
Chris@16 312
Chris@16 313 template<class H_Alpha>
Chris@16 314 static void rebalance_after_insertion
Chris@16 315 (const node_ptr &x, std::size_t depth
Chris@16 316 , std::size_t tree_size, H_Alpha h_alpha, std::size_t &max_tree_size)
Chris@16 317 {
Chris@16 318 if(tree_size > max_tree_size)
Chris@16 319 max_tree_size = tree_size;
Chris@16 320
Chris@101 321 if(tree_size > 2 && //Nothing to do with only the root
Chris@16 322 //Check if the root node is unbalanced
Chris@16 323 //Scapegoat paper depth counts root depth as zero and "depth" counts root as 1,
Chris@16 324 //but since "depth" is the depth of the ancestor of x, i == depth
Chris@16 325 depth > h_alpha(tree_size)){
Chris@101 326
Chris@16 327 //Find the first non height-balanced node
Chris@16 328 //as described in the section 4.2 of the paper.
Chris@16 329 //This method is the alternative method described
Chris@16 330 //in the paper. Authors claim that this method
Chris@16 331 //may tend to yield more balanced trees on the average
Chris@16 332 //than the weight balanced method.
Chris@16 333 node_ptr s = x;
Chris@16 334 std::size_t size = 1;
Chris@101 335 for(std::size_t ancestor = 1; ancestor != depth; ++ancestor){
Chris@101 336 const node_ptr s_parent = NodeTraits::get_parent(s);
Chris@101 337 const node_ptr s_parent_left = NodeTraits::get_left(s_parent);
Chris@101 338 //Obtain parent's size (previous size + parent + sibling tree)
Chris@101 339 const node_ptr s_sibling = s_parent_left == s ? NodeTraits::get_right(s_parent) : s_parent_left;
Chris@101 340 size += 1 + bstree_algo::subtree_size(s_sibling);
Chris@101 341 s = s_parent;
Chris@101 342 if(ancestor > h_alpha(size)){ //is 's' scapegoat?
Chris@101 343 bstree_algo::rebalance_subtree(s);
Chris@101 344 return;
Chris@16 345 }
Chris@16 346 }
Chris@101 347 //The whole tree must be rebuilt
Chris@101 348 max_tree_size = tree_size;
Chris@101 349 bstree_algo::rebalance_subtree(NodeTraits::get_parent(s));
Chris@16 350 }
Chris@16 351 }
Chris@16 352 /// @endcond
Chris@16 353 };
Chris@16 354
Chris@16 355 /// @cond
Chris@16 356
Chris@16 357 template<class NodeTraits>
Chris@16 358 struct get_algo<SgTreeAlgorithms, NodeTraits>
Chris@16 359 {
Chris@16 360 typedef sgtree_algorithms<NodeTraits> type;
Chris@16 361 };
Chris@16 362
Chris@101 363 template <class ValueTraits, class NodePtrCompare, class ExtraChecker>
Chris@101 364 struct get_node_checker<SgTreeAlgorithms, ValueTraits, NodePtrCompare, ExtraChecker>
Chris@101 365 {
Chris@101 366 typedef detail::bstree_node_checker<ValueTraits, NodePtrCompare, ExtraChecker> type;
Chris@101 367 };
Chris@101 368
Chris@16 369 /// @endcond
Chris@16 370
Chris@16 371 } //namespace intrusive
Chris@16 372 } //namespace boost
Chris@16 373
Chris@16 374 #include <boost/intrusive/detail/config_end.hpp>
Chris@16 375
Chris@16 376 #endif //BOOST_INTRUSIVE_SGTREE_ALGORITHMS_HPP