1// -*- C++ -*-
2
3// Copyright (C) 2005-2013 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library.  This library is free
6// software; you can redistribute it and/or modify it under the terms
7// of the GNU General Public License as published by the Free Software
8// Foundation; either version 3, or (at your option) any later
9// version.
10
11// This library is distributed in the hope that it will be useful, but
12// WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14// General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23// <http://www.gnu.org/licenses/>.
24
25// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
26
27// Permission to use, copy, modify, sell, and distribute this software
28// is hereby granted without fee, provided that the above copyright
29// notice appears in all copies, and that both that copyright notice
30// and this permission notice appear in supporting documentation. None
31// of the above authors, nor IBM Haifa Research Laboratories, make any
32// representation about the suitability of this software for any
33// purpose. It is provided "as is" without express or implied
34// warranty.
35
36/**
37 * @file splay_tree_/splay_fn_imps.hpp
38 * Contains an implementation class for splay_tree_.
39 */
40
41PB_DS_CLASS_T_DEC
42void
43PB_DS_CLASS_C_DEC::
44splay(node_pointer p_nd)
45{
46  while (p_nd->m_p_parent != base_type::m_p_head)
47    {
48#ifdef _GLIBCXX_DEBUG
49      {
50	node_pointer p_head = base_type::m_p_head;
51	assert_special_imp(p_head, __FILE__, __LINE__);
52      }
53#endif
54
55      PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_nd)
56
57      if (p_nd->m_p_parent->m_p_parent == base_type::m_p_head)
58	{
59	  base_type::rotate_parent(p_nd);
60	  _GLIBCXX_DEBUG_ASSERT(p_nd == this->m_p_head->m_p_parent);
61	}
62      else
63	{
64	  const node_pointer p_parent = p_nd->m_p_parent;
65	  const node_pointer p_grandparent = p_parent->m_p_parent;
66
67#ifdef _GLIBCXX_DEBUG
68	  const size_type total =
69	    base_type::recursive_count(p_grandparent);
70	  _GLIBCXX_DEBUG_ASSERT(total >= 3);
71#endif
72
73	  if (p_parent->m_p_left == p_nd &&
74	      p_grandparent->m_p_right == p_parent)
75	    splay_zig_zag_left(p_nd, p_parent, p_grandparent);
76	  else if (p_parent->m_p_right == p_nd &&
77		   p_grandparent->m_p_left == p_parent)
78	    splay_zig_zag_right(p_nd, p_parent, p_grandparent);
79	  else if (p_parent->m_p_left == p_nd &&
80		   p_grandparent->m_p_left == p_parent)
81	    splay_zig_zig_left(p_nd, p_parent, p_grandparent);
82	  else
83	    splay_zig_zig_right(p_nd, p_parent, p_grandparent);
84	  _GLIBCXX_DEBUG_ASSERT(total ==this->recursive_count(p_nd));
85	}
86
87      PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_nd)
88    }
89}
90
91PB_DS_CLASS_T_DEC
92inline void
93PB_DS_CLASS_C_DEC::
94splay_zig_zag_left(node_pointer p_nd, node_pointer p_parent,
95		   node_pointer p_grandparent)
96{
97  _GLIBCXX_DEBUG_ASSERT(p_parent == p_nd->m_p_parent);
98  _GLIBCXX_DEBUG_ASSERT(p_grandparent == p_parent->m_p_parent);
99
100  PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_grandparent)
101
102  _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_left == p_nd &&
103			p_grandparent->m_p_right == p_parent);
104
105  splay_zz_start(p_nd, p_parent, p_grandparent);
106
107  node_pointer p_b = p_nd->m_p_right;
108  node_pointer p_c = p_nd->m_p_left;
109
110  p_nd->m_p_right = p_parent;
111  p_parent->m_p_parent = p_nd;
112
113  p_nd->m_p_left = p_grandparent;
114  p_grandparent->m_p_parent = p_nd;
115
116  p_parent->m_p_left = p_b;
117  if (p_b != 0)
118    p_b->m_p_parent = p_parent;
119
120  p_grandparent->m_p_right = p_c;
121  if (p_c != 0)
122    p_c->m_p_parent = p_grandparent;
123
124  splay_zz_end(p_nd, p_parent, p_grandparent);
125}
126
127PB_DS_CLASS_T_DEC
128inline void
129PB_DS_CLASS_C_DEC::
130splay_zig_zag_right(node_pointer p_nd, node_pointer p_parent,
131		    node_pointer p_grandparent)
132{
133  _GLIBCXX_DEBUG_ASSERT(p_parent == p_nd->m_p_parent);
134  _GLIBCXX_DEBUG_ASSERT(p_grandparent == p_parent->m_p_parent);
135
136  PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_grandparent)
137
138  _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_right == p_nd &&
139	  		p_grandparent->m_p_left == p_parent);
140
141  splay_zz_start(p_nd, p_parent, p_grandparent);
142
143  node_pointer p_b = p_nd->m_p_left;
144  node_pointer p_c = p_nd->m_p_right;
145
146  p_nd->m_p_left = p_parent;
147  p_parent->m_p_parent = p_nd;
148
149  p_nd->m_p_right = p_grandparent;
150  p_grandparent->m_p_parent = p_nd;
151
152  p_parent->m_p_right = p_b;
153  if (p_b != 0)
154    p_b->m_p_parent = p_parent;
155
156  p_grandparent->m_p_left = p_c;
157  if (p_c != 0)
158    p_c->m_p_parent = p_grandparent;
159
160  splay_zz_end(p_nd, p_parent, p_grandparent);
161}
162
163PB_DS_CLASS_T_DEC
164inline void
165PB_DS_CLASS_C_DEC::
166splay_zig_zig_left(node_pointer p_nd, node_pointer p_parent,
167		   node_pointer p_grandparent)
168{
169  _GLIBCXX_DEBUG_ASSERT(p_parent == p_nd->m_p_parent);
170  _GLIBCXX_DEBUG_ASSERT(p_grandparent == p_parent->m_p_parent);
171
172  PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_grandparent)
173
174  _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_left == p_nd &&
175		     p_nd->m_p_parent->m_p_parent->m_p_left == p_nd->m_p_parent);
176
177  splay_zz_start(p_nd, p_parent, p_grandparent);
178
179  node_pointer p_b = p_nd->m_p_right;
180  node_pointer p_c = p_parent->m_p_right;
181
182  p_nd->m_p_right = p_parent;
183  p_parent->m_p_parent = p_nd;
184
185  p_parent->m_p_right = p_grandparent;
186  p_grandparent->m_p_parent = p_parent;
187
188  p_parent->m_p_left = p_b;
189  if (p_b != 0)
190    p_b->m_p_parent = p_parent;
191
192  p_grandparent->m_p_left = p_c;
193  if (p_c != 0)
194    p_c->m_p_parent = p_grandparent;
195
196  splay_zz_end(p_nd, p_parent, p_grandparent);
197}
198
199PB_DS_CLASS_T_DEC
200inline void
201PB_DS_CLASS_C_DEC::
202splay_zig_zig_right(node_pointer p_nd, node_pointer p_parent,
203		    node_pointer p_grandparent)
204{
205  _GLIBCXX_DEBUG_ASSERT(p_parent == p_nd->m_p_parent);
206  _GLIBCXX_DEBUG_ASSERT(p_grandparent == p_parent->m_p_parent);
207  PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_grandparent)
208  _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_right == p_nd &&
209		  p_nd->m_p_parent->m_p_parent->m_p_right == p_nd->m_p_parent);
210
211  splay_zz_start(p_nd, p_parent, p_grandparent);
212
213  node_pointer p_b = p_nd->m_p_left;
214  node_pointer p_c = p_parent->m_p_left;
215
216  p_nd->m_p_left = p_parent;
217  p_parent->m_p_parent = p_nd;
218
219  p_parent->m_p_left = p_grandparent;
220  p_grandparent->m_p_parent = p_parent;
221
222  p_parent->m_p_right = p_b;
223  if (p_b != 0)
224    p_b->m_p_parent = p_parent;
225
226  p_grandparent->m_p_right = p_c;
227  if (p_c != 0)
228    p_c->m_p_parent = p_grandparent;
229
230  base_type::update_to_top(p_grandparent, (node_update*)this);
231  splay_zz_end(p_nd, p_parent, p_grandparent);
232}
233
234PB_DS_CLASS_T_DEC
235inline void
236PB_DS_CLASS_C_DEC::
237splay_zz_start(node_pointer p_nd,
238#ifdef _GLIBCXX_DEBUG
239	       node_pointer p_parent,
240#else
241	       node_pointer /*p_parent*/,
242#endif
243	       node_pointer p_grandparent)
244{
245  _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
246  _GLIBCXX_DEBUG_ASSERT(p_parent != 0);
247  _GLIBCXX_DEBUG_ASSERT(p_grandparent != 0);
248
249  const bool grandparent_head = p_grandparent->m_p_parent == base_type::m_p_head;
250
251  if (grandparent_head)
252    {
253      base_type::m_p_head->m_p_parent = base_type::m_p_head->m_p_parent;
254      p_nd->m_p_parent = base_type::m_p_head;
255      return;
256    }
257
258  node_pointer p_greatgrandparent = p_grandparent->m_p_parent;
259
260  p_nd->m_p_parent = p_greatgrandparent;
261
262  if (p_grandparent == p_greatgrandparent->m_p_left)
263    p_greatgrandparent->m_p_left = p_nd;
264  else
265    p_greatgrandparent->m_p_right = p_nd;
266}
267
268PB_DS_CLASS_T_DEC
269inline void
270PB_DS_CLASS_C_DEC::
271splay_zz_end(node_pointer p_nd, node_pointer p_parent,
272	     node_pointer p_grandparent)
273{
274  if (p_nd->m_p_parent == base_type::m_p_head)
275    base_type::m_p_head->m_p_parent = p_nd;
276
277  this->apply_update(p_grandparent, (node_update*)this);
278  this->apply_update(p_parent, (node_update*)this);
279  this->apply_update(p_nd, (node_update*)this);
280  PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_nd)
281}
282