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      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 
     41 PB_DS_CLASS_T_DEC
     42 void
     43 PB_DS_CLASS_C_DEC::
     44 splay(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 
     91 PB_DS_CLASS_T_DEC
     92 inline void
     93 PB_DS_CLASS_C_DEC::
     94 splay_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 
    127 PB_DS_CLASS_T_DEC
    128 inline void
    129 PB_DS_CLASS_C_DEC::
    130 splay_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 
    163 PB_DS_CLASS_T_DEC
    164 inline void
    165 PB_DS_CLASS_C_DEC::
    166 splay_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 
    199 PB_DS_CLASS_T_DEC
    200 inline void
    201 PB_DS_CLASS_C_DEC::
    202 splay_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 
    234 PB_DS_CLASS_T_DEC
    235 inline void
    236 PB_DS_CLASS_C_DEC::
    237 splay_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 
    268 PB_DS_CLASS_T_DEC
    269 inline void
    270 PB_DS_CLASS_C_DEC::
    271 splay_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