1/////////////////////////////////////////////////////////////////////////////
2//
3// (C) Copyright Ion Gaztanaga 2007-2014
4//
5// Distributed under the Boost Software License, Version 1.0.
6// (See accompanying file LICENSE_1_0.txt or copy at
7// http://www.boost.org/LICENSE_1_0.txt)
8//
9// See http://www.boost.org/libs/intrusive for documentation.
10//
11/////////////////////////////////////////////////////////////////////////////
12// The implementation of splay trees is based on the article and code published
13// in C++ Users Journal "Implementing Splay Trees in C++" (September 1, 2005).
14//
15// The splay code has been modified and (supposedly) improved by Ion Gaztanaga.
16//
17// Here is the copyright notice of the original file containing the splay code:
18//
19// splay_tree.h -- implementation of a STL compatible splay tree.
20//
21// Copyright (c) 2004 Ralf Mattethat
22//
23// Permission to copy, use, modify, sell and distribute this software
24// is granted provided this copyright notice appears in all copies.
25// This software is provided "as is" without express or implied
26// warranty, and with no claim as to its suitability for any purpose.
27//
28/////////////////////////////////////////////////////////////////////////////
29
30#ifndef BOOST_INTRUSIVE_SPLAYTREE_ALGORITHMS_HPP
31#define BOOST_INTRUSIVE_SPLAYTREE_ALGORITHMS_HPP
32
33#include <boost/intrusive/detail/config_begin.hpp>
34#include <boost/intrusive/intrusive_fwd.hpp>
35#include <boost/intrusive/detail/assert.hpp>
36#include <boost/intrusive/detail/algo_type.hpp>
37#include <boost/intrusive/detail/uncast.hpp>
38#include <boost/intrusive/bstree_algorithms.hpp>
39
40#include <cstddef>
41
42#if defined(BOOST_HAS_PRAGMA_ONCE)
43# pragma once
44#endif
45
46namespace boost {
47namespace intrusive {
48
49/// @cond
50namespace detail {
51
52template<class NodeTraits>
53struct splaydown_assemble_and_fix_header
54{
55 typedef typename NodeTraits::node_ptr node_ptr;
56
57 splaydown_assemble_and_fix_header(node_ptr t, node_ptr header, node_ptr leftmost, node_ptr rightmost) BOOST_NOEXCEPT
58 : t_(t)
59 , null_node_(header)
60 , l_(null_node_)
61 , r_(null_node_)
62 , leftmost_(leftmost)
63 , rightmost_(rightmost)
64 {}
65
66 ~splaydown_assemble_and_fix_header()
67 {
68 this->assemble();
69
70 //Now recover the original header except for the
71 //splayed root node.
72 //"t_" is the current root and "null_node_" is the header node
73 NodeTraits::set_parent(null_node_, t_);
74 NodeTraits::set_parent(t_, null_node_);
75 //Recover leftmost/rightmost pointers
76 NodeTraits::set_left (null_node_, leftmost_);
77 NodeTraits::set_right(null_node_, rightmost_);
78 }
79
80 private:
81
82 void assemble() BOOST_NOEXCEPT
83 {
84 //procedure assemble;
85 // left(r), right(l) := right(t), left(t);
86 // left(t), right(t) := right(null), left(null);
87 //end assemble;
88 { // left(r), right(l) := right(t), left(t);
89
90 node_ptr const old_t_left = NodeTraits::get_left(t_);
91 node_ptr const old_t_right = NodeTraits::get_right(t_);
92 NodeTraits::set_right(l_, old_t_left);
93 NodeTraits::set_left (r_, old_t_right);
94 if(old_t_left){
95 NodeTraits::set_parent(old_t_left, l_);
96 }
97 if(old_t_right){
98 NodeTraits::set_parent(old_t_right, r_);
99 }
100 }
101 { // left(t), right(t) := right(null), left(null);
102 node_ptr const null_right = NodeTraits::get_right(null_node_);
103 node_ptr const null_left = NodeTraits::get_left(null_node_);
104 NodeTraits::set_left (t_, null_right);
105 NodeTraits::set_right(t_, null_left);
106 if(null_right){
107 NodeTraits::set_parent(null_right, t_);
108 }
109 if(null_left){
110 NodeTraits::set_parent(null_left, t_);
111 }
112 }
113 }
114
115 public:
116 node_ptr t_, null_node_, l_, r_, leftmost_, rightmost_;
117};
118
119} //namespace detail {
120/// @endcond
121
122//! A splay tree is an implementation of a binary search tree. The tree is
123//! self balancing using the splay algorithm as described in
124//!
125//! "Self-Adjusting Binary Search Trees
126//! by Daniel Dominic Sleator and Robert Endre Tarjan
127//! AT&T Bell Laboratories, Murray Hill, NJ
128//! Journal of the ACM, Vol 32, no 3, July 1985, pp 652-686
129//!
130//! splaytree_algorithms is configured with a NodeTraits class, which encapsulates the
131//! information about the node to be manipulated. NodeTraits must support the
132//! following interface:
133//!
134//! <b>Typedefs</b>:
135//!
136//! <tt>node</tt>: The type of the node that forms the binary search tree
137//!
138//! <tt>node_ptr</tt>: A pointer to a node
139//!
140//! <tt>const_node_ptr</tt>: A pointer to a const node
141//!
142//! <b>Static functions</b>:
143//!
144//! <tt>static node_ptr get_parent(const_node_ptr n);</tt>
145//!
146//! <tt>static void set_parent(node_ptr n, node_ptr parent);</tt>
147//!
148//! <tt>static node_ptr get_left(const_node_ptr n);</tt>
149//!
150//! <tt>static void set_left(node_ptr n, node_ptr left);</tt>
151//!
152//! <tt>static node_ptr get_right(const_node_ptr n);</tt>
153//!
154//! <tt>static void set_right(node_ptr n, node_ptr right);</tt>
155template<class NodeTraits>
156class splaytree_algorithms
157 #ifndef BOOST_INTRUSIVE_DOXYGEN_INVOKED
158 : public bstree_algorithms<NodeTraits>
159 #endif
160{
161 /// @cond
162 private:
163 typedef bstree_algorithms<NodeTraits> bstree_algo;
164 /// @endcond
165
166 public:
167 typedef typename NodeTraits::node node;
168 typedef NodeTraits node_traits;
169 typedef typename NodeTraits::node_ptr node_ptr;
170 typedef typename NodeTraits::const_node_ptr const_node_ptr;
171
172 //! This type is the information that will be
173 //! filled by insert_unique_check
174 typedef typename bstree_algo::insert_commit_data insert_commit_data;
175
176 public:
177 #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
178 //! @copydoc ::boost::intrusive::bstree_algorithms::get_header(const_node_ptr)
179 static node_ptr get_header(const_node_ptr n) BOOST_NOEXCEPT;
180
181 //! @copydoc ::boost::intrusive::bstree_algorithms::begin_node
182 static node_ptr begin_node(const_node_ptr header) BOOST_NOEXCEPT;
183
184 //! @copydoc ::boost::intrusive::bstree_algorithms::end_node
185 static node_ptr end_node(const_node_ptr header) BOOST_NOEXCEPT;
186
187 //! @copydoc ::boost::intrusive::bstree_algorithms::swap_tree
188 static void swap_tree(node_ptr header1, node_ptr header2);
189
190 //! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(node_ptr,node_ptr)
191 static void swap_nodes(node_ptr node1, node_ptr node2) BOOST_NOEXCEPT;
192
193 //! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(node_ptr,node_ptr,node_ptr,node_ptr)
194 static void swap_nodes(node_ptr node1, node_ptr header1, node_ptr node2, node_ptr header2) BOOST_NOEXCEPT;
195
196 //! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(node_ptr,node_ptr)
197 static void replace_node(node_ptr node_to_be_replaced, node_ptr new_node) BOOST_NOEXCEPT;
198
199 //! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(node_ptr,node_ptr,node_ptr)
200 static void replace_node(node_ptr node_to_be_replaced, node_ptr header, node_ptr new_node) BOOST_NOEXCEPT;
201
202 //! @copydoc ::boost::intrusive::bstree_algorithms::unlink(node_ptr)
203 static void unlink(node_ptr n) BOOST_NOEXCEPT;
204
205 //! @copydoc ::boost::intrusive::bstree_algorithms::unlink_leftmost_without_rebalance
206 static node_ptr unlink_leftmost_without_rebalance(node_ptr header) BOOST_NOEXCEPT;
207
208 //! @copydoc ::boost::intrusive::bstree_algorithms::unique(const_node_ptr)
209 static bool unique(const_node_ptr n) BOOST_NOEXCEPT;
210
211 //! @copydoc ::boost::intrusive::bstree_algorithms::size(const_node_ptr)
212 static std::size_t size(const_node_ptr header) BOOST_NOEXCEPT;
213
214 //! @copydoc ::boost::intrusive::bstree_algorithms::next_node(node_ptr)
215 static node_ptr next_node(node_ptr n) BOOST_NOEXCEPT;
216
217 //! @copydoc ::boost::intrusive::bstree_algorithms::prev_node(node_ptr)
218 static node_ptr prev_node(node_ptr n) BOOST_NOEXCEPT;
219
220 //! @copydoc ::boost::intrusive::bstree_algorithms::init(node_ptr)
221 static void init(node_ptr n) BOOST_NOEXCEPT;
222
223 //! @copydoc ::boost::intrusive::bstree_algorithms::init_header(node_ptr)
224 static void init_header(node_ptr header) BOOST_NOEXCEPT;
225
226 #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
227
228 //! @copydoc ::boost::intrusive::bstree_algorithms::erase(node_ptr,node_ptr)
229 //! Additional notes: the previous node of z is splayed to speed up range deletions.
230 static void erase(node_ptr header, node_ptr z) BOOST_NOEXCEPT
231 {
232 //posibility 1
233 if(NodeTraits::get_left(z)){
234 splay_up(n: bstree_algo::prev_node(z), header);
235 }
236
237 //possibility 2
238 //if(NodeTraits::get_left(z)){
239 // node_ptr l = NodeTraits::get_left(z);
240 // splay_up(l, header);
241 //}
242
243 //if(NodeTraits::get_left(z)){
244 // node_ptr l = bstree_algo::prev_node(z);
245 // splay_up_impl(l, z);
246 //}
247
248 //possibility 4
249 //splay_up(z, header);
250
251 bstree_algo::erase(header, z);
252 }
253
254 //! @copydoc ::boost::intrusive::bstree_algorithms::transfer_unique
255 template<class NodePtrCompare>
256 static bool transfer_unique
257 (node_ptr header1, NodePtrCompare comp, node_ptr header2, node_ptr z)
258 {
259 typename bstree_algo::insert_commit_data commit_data;
260 bool const transferable = bstree_algo::insert_unique_check(header1, z, comp, commit_data).second;
261 if(transferable){
262 erase(header: header2, z);
263 bstree_algo::insert_commit(header1, z, commit_data);
264 splay_up(n: z, header: header1);
265 }
266 return transferable;
267 }
268
269 //! @copydoc ::boost::intrusive::bstree_algorithms::transfer_equal
270 template<class NodePtrCompare>
271 static void transfer_equal
272 (node_ptr header1, NodePtrCompare comp, node_ptr header2, node_ptr z)
273 {
274 insert_commit_data commit_data;
275 splay_down(header1, z, comp);
276 bstree_algo::insert_equal_upper_bound_check(header1, z, comp, commit_data);
277 erase(header: header2, z);
278 bstree_algo::insert_commit(header1, z, commit_data);
279 }
280
281 #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
282 //! @copydoc ::boost::intrusive::bstree_algorithms::clone(const_node_ptr,node_ptr,Cloner,Disposer)
283 template <class Cloner, class Disposer>
284 static void clone
285 (const_node_ptr source_header, node_ptr target_header, Cloner cloner, Disposer disposer);
286
287 //! @copydoc ::boost::intrusive::bstree_algorithms::clear_and_dispose(node_ptr,Disposer)
288 template<class Disposer>
289 static void clear_and_dispose(node_ptr header, Disposer disposer) BOOST_NOEXCEPT;
290
291 #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
292 //! @copydoc ::boost::intrusive::bstree_algorithms::count(const_node_ptr,const KeyType&,KeyNodePtrCompare)
293 //! Additional notes: an element with key `key` is splayed.
294 template<class KeyType, class KeyNodePtrCompare>
295 static std::size_t count
296 (node_ptr header, const KeyType &key, KeyNodePtrCompare comp)
297 {
298 std::pair<node_ptr, node_ptr> ret = equal_range(header, key, comp);
299 std::size_t n = 0;
300 while(ret.first != ret.second){
301 ++n;
302 ret.first = next_node(ret.first);
303 }
304 return n;
305 }
306
307 //! @copydoc ::boost::intrusive::bstree_algorithms::count(const_node_ptr,const KeyType&,KeyNodePtrCompare)
308 //! Additional note: no splaying is performed
309 template<class KeyType, class KeyNodePtrCompare>
310 static std::size_t count
311 (const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp)
312 { return bstree_algo::count(header, key, comp); }
313
314 //! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound(const_node_ptr,const KeyType&,KeyNodePtrCompare)
315 //! Additional notes: the first node of the range is splayed.
316 template<class KeyType, class KeyNodePtrCompare>
317 static node_ptr lower_bound
318 (node_ptr header, const KeyType &key, KeyNodePtrCompare comp)
319 {
320 splay_down(detail::uncast(header), key, comp);
321 node_ptr y = bstree_algo::lower_bound(header, key, comp);
322 //splay_up(y, detail::uncast(header));
323 return y;
324 }
325
326 //! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound(const_node_ptr,const KeyType&,KeyNodePtrCompare)
327 //! Additional note: no splaying is performed
328 template<class KeyType, class KeyNodePtrCompare>
329 static node_ptr lower_bound
330 (const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp)
331 { return bstree_algo::lower_bound(header, key, comp); }
332
333 //! @copydoc ::boost::intrusive::bstree_algorithms::upper_bound(const_node_ptr,const KeyType&,KeyNodePtrCompare)
334 //! Additional notes: the first node of the range is splayed.
335 template<class KeyType, class KeyNodePtrCompare>
336 static node_ptr upper_bound
337 (node_ptr header, const KeyType &key, KeyNodePtrCompare comp)
338 {
339 splay_down(detail::uncast(header), key, comp);
340 node_ptr y = bstree_algo::upper_bound(header, key, comp);
341 //splay_up(y, detail::uncast(header));
342 return y;
343 }
344
345 //! @copydoc ::boost::intrusive::bstree_algorithms::upper_bound(const_node_ptr,const KeyType&,KeyNodePtrCompare)
346 //! Additional note: no splaying is performed
347 template<class KeyType, class KeyNodePtrCompare>
348 static node_ptr upper_bound
349 (const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp)
350 { return bstree_algo::upper_bound(header, key, comp); }
351
352 //! @copydoc ::boost::intrusive::bstree_algorithms::find(const_node_ptr, const KeyType&,KeyNodePtrCompare)
353 //! Additional notes: the found node of the lower bound is splayed.
354 template<class KeyType, class KeyNodePtrCompare>
355 static node_ptr find
356 (node_ptr header, const KeyType &key, KeyNodePtrCompare comp)
357 {
358 splay_down(detail::uncast(header), key, comp);
359 return bstree_algo::find(header, key, comp);
360 }
361
362 //! @copydoc ::boost::intrusive::bstree_algorithms::find(const_node_ptr, const KeyType&,KeyNodePtrCompare)
363 //! Additional note: no splaying is performed
364 template<class KeyType, class KeyNodePtrCompare>
365 static node_ptr find
366 (const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp)
367 { return bstree_algo::find(header, key, comp); }
368
369 //! @copydoc ::boost::intrusive::bstree_algorithms::equal_range(const_node_ptr,const KeyType&,KeyNodePtrCompare)
370 //! Additional notes: the first node of the range is splayed.
371 template<class KeyType, class KeyNodePtrCompare>
372 static std::pair<node_ptr, node_ptr> equal_range
373 (node_ptr header, const KeyType &key, KeyNodePtrCompare comp)
374 {
375 splay_down(detail::uncast(header), key, comp);
376 std::pair<node_ptr, node_ptr> ret = bstree_algo::equal_range(header, key, comp);
377 //splay_up(ret.first, detail::uncast(header));
378 return ret;
379 }
380
381 //! @copydoc ::boost::intrusive::bstree_algorithms::equal_range(const_node_ptr,const KeyType&,KeyNodePtrCompare)
382 //! Additional note: no splaying is performed
383 template<class KeyType, class KeyNodePtrCompare>
384 static std::pair<node_ptr, node_ptr> equal_range
385 (const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp)
386 { return bstree_algo::equal_range(header, key, comp); }
387
388 //! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound_range(const_node_ptr,const KeyType&,KeyNodePtrCompare)
389 //! Additional notes: the first node of the range is splayed.
390 template<class KeyType, class KeyNodePtrCompare>
391 static std::pair<node_ptr, node_ptr> lower_bound_range
392 (node_ptr header, const KeyType &key, KeyNodePtrCompare comp)
393 {
394 splay_down(detail::uncast(header), key, comp);
395 std::pair<node_ptr, node_ptr> ret = bstree_algo::lower_bound_range(header, key, comp);
396 //splay_up(ret.first, detail::uncast(header));
397 return ret;
398 }
399
400 //! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound_range(const_node_ptr,const KeyType&,KeyNodePtrCompare)
401 //! Additional note: no splaying is performed
402 template<class KeyType, class KeyNodePtrCompare>
403 static std::pair<node_ptr, node_ptr> lower_bound_range
404 (const_node_ptr header, const KeyType &key, KeyNodePtrCompare comp)
405 { return bstree_algo::lower_bound_range(header, key, comp); }
406
407 //! @copydoc ::boost::intrusive::bstree_algorithms::bounded_range(const_node_ptr,const KeyType&,const KeyType&,KeyNodePtrCompare,bool,bool)
408 //! Additional notes: the first node of the range is splayed.
409 template<class KeyType, class KeyNodePtrCompare>
410 static std::pair<node_ptr, node_ptr> bounded_range
411 (node_ptr header, const KeyType &lower_key, const KeyType &upper_key, KeyNodePtrCompare comp
412 , bool left_closed, bool right_closed)
413 {
414 splay_down(detail::uncast(header), lower_key, comp);
415 std::pair<node_ptr, node_ptr> ret =
416 bstree_algo::bounded_range(header, lower_key, upper_key, comp, left_closed, right_closed);
417 //splay_up(ret.first, detail::uncast(header));
418 return ret;
419 }
420
421 //! @copydoc ::boost::intrusive::bstree_algorithms::bounded_range(const_node_ptr,const KeyType&,const KeyType&,KeyNodePtrCompare,bool,bool)
422 //! Additional note: no splaying is performed
423 template<class KeyType, class KeyNodePtrCompare>
424 static std::pair<node_ptr, node_ptr> bounded_range
425 (const_node_ptr header, const KeyType &lower_key, const KeyType &upper_key, KeyNodePtrCompare comp
426 , bool left_closed, bool right_closed)
427 { return bstree_algo::bounded_range(header, lower_key, upper_key, comp, left_closed, right_closed); }
428
429 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal_upper_bound(node_ptr,node_ptr,NodePtrCompare)
430 //! Additional note: the inserted node is splayed
431 template<class NodePtrCompare>
432 static node_ptr insert_equal_upper_bound
433 (node_ptr header, node_ptr new_node, NodePtrCompare comp)
434 {
435 splay_down(header, new_node, comp);
436 return bstree_algo::insert_equal_upper_bound(header, new_node, comp);
437 }
438
439 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal_lower_bound(node_ptr,node_ptr,NodePtrCompare)
440 //! Additional note: the inserted node is splayed
441 template<class NodePtrCompare>
442 static node_ptr insert_equal_lower_bound
443 (node_ptr header, node_ptr new_node, NodePtrCompare comp)
444 {
445 splay_down(header, new_node, comp);
446 return bstree_algo::insert_equal_lower_bound(header, new_node, comp);
447 }
448
449 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal(node_ptr,node_ptr,node_ptr,NodePtrCompare)
450 //! Additional note: the inserted node is splayed
451 template<class NodePtrCompare>
452 static node_ptr insert_equal
453 (node_ptr header, node_ptr hint, node_ptr new_node, NodePtrCompare comp)
454 {
455 splay_down(header, new_node, comp);
456 return bstree_algo::insert_equal(header, hint, new_node, comp);
457 }
458
459 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_before(node_ptr,node_ptr,node_ptr)
460 //! Additional note: the inserted node is splayed
461 static node_ptr insert_before
462 (node_ptr header, node_ptr pos, node_ptr new_node) BOOST_NOEXCEPT
463 {
464 bstree_algo::insert_before(header, pos, new_node);
465 splay_up(n: new_node, header);
466 return new_node;
467 }
468
469 //! @copydoc ::boost::intrusive::bstree_algorithms::push_back(node_ptr,node_ptr)
470 //! Additional note: the inserted node is splayed
471 static void push_back(node_ptr header, node_ptr new_node) BOOST_NOEXCEPT
472 {
473 bstree_algo::push_back(header, new_node);
474 splay_up(n: new_node, header);
475 }
476
477 //! @copydoc ::boost::intrusive::bstree_algorithms::push_front(node_ptr,node_ptr)
478 //! Additional note: the inserted node is splayed
479 static void push_front(node_ptr header, node_ptr new_node) BOOST_NOEXCEPT
480 {
481 bstree_algo::push_front(header, new_node);
482 splay_up(n: new_node, header);
483 }
484
485 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_check(const_node_ptr,const KeyType&,KeyNodePtrCompare,insert_commit_data&)
486 //! Additional note: nodes with the given key are splayed
487 template<class KeyType, class KeyNodePtrCompare>
488 static std::pair<node_ptr, bool> insert_unique_check
489 (node_ptr header, const KeyType &key
490 ,KeyNodePtrCompare comp, insert_commit_data &commit_data)
491 {
492 splay_down(header, key, comp);
493 return bstree_algo::insert_unique_check(header, key, comp, commit_data);
494 }
495
496 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_check(const_node_ptr,node_ptr,const KeyType&,KeyNodePtrCompare,insert_commit_data&)
497 //! Additional note: nodes with the given key are splayed
498 template<class KeyType, class KeyNodePtrCompare>
499 static std::pair<node_ptr, bool> insert_unique_check
500 (node_ptr header, node_ptr hint, const KeyType &key
501 ,KeyNodePtrCompare comp, insert_commit_data &commit_data)
502 {
503 splay_down(header, key, comp);
504 return bstree_algo::insert_unique_check(header, hint, key, comp, commit_data);
505 }
506
507 #ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
508 //! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_commit(node_ptr,node_ptr,const insert_commit_data&)
509 static void insert_unique_commit
510 (node_ptr header, node_ptr new_value, const insert_commit_data &commit_data) BOOST_NOEXCEPT;
511
512 //! @copydoc ::boost::intrusive::bstree_algorithms::is_header
513 static bool is_header(const_node_ptr p) BOOST_NOEXCEPT;
514
515 //! @copydoc ::boost::intrusive::bstree_algorithms::rebalance
516 static void rebalance(node_ptr header) BOOST_NOEXCEPT;
517
518 //! @copydoc ::boost::intrusive::bstree_algorithms::rebalance_subtree
519 static node_ptr rebalance_subtree(node_ptr old_root) BOOST_NOEXCEPT;
520
521 #endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
522
523 // bottom-up splay, use data_ as parent for n | complexity : logarithmic | exception : nothrow
524 static void splay_up(node_ptr n, node_ptr header) BOOST_NOEXCEPT
525 { priv_splay_up<true>(n, header); }
526
527 // top-down splay | complexity : logarithmic | exception : strong, note A
528 template<class KeyType, class KeyNodePtrCompare>
529 static node_ptr splay_down(node_ptr header, const KeyType &key, KeyNodePtrCompare comp, bool *pfound = 0)
530 { return priv_splay_down<true>(header, key, comp, pfound); }
531
532 private:
533
534 /// @cond
535
536 // bottom-up splay, use data_ as parent for n | complexity : logarithmic | exception : nothrow
537 template<bool SimpleSplay>
538 static void priv_splay_up(node_ptr n, node_ptr header) BOOST_NOEXCEPT
539 {
540 // If (node == header) do a splay for the right most node instead
541 // this is to boost performance of equal_range/count on equivalent containers in the case
542 // where there are many equal elements at the end
543 if(n == header)
544 n = NodeTraits::get_right(header);
545
546 node_ptr t(header);
547
548 if( n == t ) return;
549
550 for( ;; ){
551 node_ptr p(NodeTraits::get_parent(n));
552 node_ptr g(NodeTraits::get_parent(p));
553
554 if( p == t ) break;
555
556 if( g == t ){
557 // zig
558 rotate(n);
559 }
560 else if ((NodeTraits::get_left(p) == n && NodeTraits::get_left(g) == p) ||
561 (NodeTraits::get_right(p) == n && NodeTraits::get_right(g) == p) ){
562 // zig-zig
563 rotate(n: p);
564 rotate(n);
565 }
566 else {
567 // zig-zag
568 rotate(n);
569 if(!SimpleSplay){
570 rotate(n);
571 }
572 }
573 }
574 }
575
576 template<bool SimpleSplay, class KeyType, class KeyNodePtrCompare>
577 static node_ptr priv_splay_down(node_ptr header, const KeyType &key, KeyNodePtrCompare comp, bool *pfound = 0)
578 {
579 //Most splay tree implementations use a dummy/null node to implement.
580 //this function. This has some problems for a generic library like Intrusive:
581 //
582 // * The node might not have a default constructor.
583 // * The default constructor could throw.
584 //
585 //We already have a header node. Leftmost and rightmost nodes of the tree
586 //are not changed when splaying (because the invariants of the tree don't
587 //change) We can back up them, use the header as the null node and
588 //reassign old values after the function has been completed.
589 node_ptr const old_root = NodeTraits::get_parent(header);
590 node_ptr const leftmost = NodeTraits::get_left(header);
591 node_ptr const rightmost = NodeTraits::get_right(header);
592 if(leftmost == rightmost){ //Empty or unique node
593 if(pfound){
594 *pfound = old_root && !comp(key, old_root) && !comp(old_root, key);
595 }
596 return old_root ? old_root : header;
597 }
598 else{
599 //Initialize "null node" (the header in our case)
600 NodeTraits::set_left (header, node_ptr());
601 NodeTraits::set_right(header, node_ptr());
602 //Class that will backup leftmost/rightmost from header, commit the assemble(),
603 //and will restore leftmost/rightmost to header even if "comp" throws
604 detail::splaydown_assemble_and_fix_header<NodeTraits> commit(old_root, header, leftmost, rightmost);
605 bool found = false;
606
607 for( ;; ){
608 if(comp(key, commit.t_)){
609 node_ptr const t_left = NodeTraits::get_left(commit.t_);
610 if(!t_left)
611 break;
612 if(comp(key, t_left)){
613 bstree_algo::rotate_right_no_parent_fix(commit.t_, t_left);
614 commit.t_ = t_left;
615 if( !NodeTraits::get_left(commit.t_) )
616 break;
617 link_right(t&: commit.t_, r&: commit.r_);
618 }
619 else{
620 link_right(t&: commit.t_, r&: commit.r_);
621 if(!SimpleSplay && comp(t_left, key)){
622 if( !NodeTraits::get_right(commit.t_) )
623 break;
624 link_left(t&: commit.t_, l&: commit.l_);
625 }
626 }
627 }
628 else if(comp(commit.t_, key)){
629 node_ptr const t_right = NodeTraits::get_right(commit.t_);
630 if(!t_right)
631 break;
632
633 if(comp(t_right, key)){
634 bstree_algo::rotate_left_no_parent_fix(commit.t_, t_right);
635 commit.t_ = t_right;
636 if( !NodeTraits::get_right(commit.t_) )
637 break;
638 link_left(t&: commit.t_, l&: commit.l_);
639 }
640 else{
641 link_left(t&: commit.t_, l&: commit.l_);
642 if(!SimpleSplay && comp(key, t_right)){
643 if( !NodeTraits::get_left(commit.t_) )
644 break;
645 link_right(t&: commit.t_, r&: commit.r_);
646 }
647 }
648 }
649 else{
650 found = true;
651 break;
652 }
653 }
654
655 //commit.~splaydown_assemble_and_fix_header<NodeTraits>() will first
656 //"assemble()" + link the new root & recover header's leftmost & rightmost
657 if(pfound){
658 *pfound = found;
659 }
660 return commit.t_;
661 }
662 }
663
664 // break link to left child node and attach it to left tree pointed to by l | complexity : constant | exception : nothrow
665 static void link_left(node_ptr & t, node_ptr & l) BOOST_NOEXCEPT
666 {
667 //procedure link_left;
668 // t, l, right(l) := right(t), t, t
669 //end link_left
670 NodeTraits::set_right(l, t);
671 NodeTraits::set_parent(t, l);
672 l = t;
673 t = NodeTraits::get_right(t);
674 }
675
676 // break link to right child node and attach it to right tree pointed to by r | complexity : constant | exception : nothrow
677 static void link_right(node_ptr & t, node_ptr & r) BOOST_NOEXCEPT
678 {
679 //procedure link_right;
680 // t, r, left(r) := left(t), t, t
681 //end link_right;
682 NodeTraits::set_left(r, t);
683 NodeTraits::set_parent(t, r);
684 r = t;
685 t = NodeTraits::get_left(t);
686 }
687
688 // rotate n with its parent | complexity : constant | exception : nothrow
689 static void rotate(node_ptr n) BOOST_NOEXCEPT
690 {
691 //procedure rotate_left;
692 // t, right(t), left(right(t)) := right(t), left(right(t)), t
693 //end rotate_left;
694 node_ptr p = NodeTraits::get_parent(n);
695 node_ptr g = NodeTraits::get_parent(p);
696 //Test if g is header before breaking tree
697 //invariants that would make is_header invalid
698 bool g_is_header = bstree_algo::is_header(g);
699
700 if(NodeTraits::get_left(p) == n){
701 NodeTraits::set_left(p, NodeTraits::get_right(n));
702 if(NodeTraits::get_left(p))
703 NodeTraits::set_parent(NodeTraits::get_left(p), p);
704 NodeTraits::set_right(n, p);
705 }
706 else{ // must be ( p->right == n )
707 NodeTraits::set_right(p, NodeTraits::get_left(n));
708 if(NodeTraits::get_right(p))
709 NodeTraits::set_parent(NodeTraits::get_right(p), p);
710 NodeTraits::set_left(n, p);
711 }
712
713 NodeTraits::set_parent(p, n);
714 NodeTraits::set_parent(n, g);
715
716 if(g_is_header){
717 if(NodeTraits::get_parent(g) == p)
718 NodeTraits::set_parent(g, n);
719 else{//must be ( g->right == p )
720 BOOST_INTRUSIVE_INVARIANT_ASSERT(false);
721 NodeTraits::set_right(g, n);
722 }
723 }
724 else{
725 if(NodeTraits::get_left(g) == p)
726 NodeTraits::set_left(g, n);
727 else //must be ( g->right == p )
728 NodeTraits::set_right(g, n);
729 }
730 }
731
732 /// @endcond
733};
734
735/// @cond
736
737template<class NodeTraits>
738struct get_algo<SplayTreeAlgorithms, NodeTraits>
739{
740 typedef splaytree_algorithms<NodeTraits> type;
741};
742
743template <class ValueTraits, class NodePtrCompare, class ExtraChecker>
744struct get_node_checker<SplayTreeAlgorithms, ValueTraits, NodePtrCompare, ExtraChecker>
745{
746 typedef detail::bstree_node_checker<ValueTraits, NodePtrCompare, ExtraChecker> type;
747};
748
749/// @endcond
750
751} //namespace intrusive
752} //namespace boost
753
754#include <boost/intrusive/detail/config_end.hpp>
755
756#endif //BOOST_INTRUSIVE_SPLAYTREE_ALGORITHMS_HPP
757

source code of boost/libs/intrusive/include/boost/intrusive/splaytree_algorithms.hpp