bin_search_tree_/rotate_fn_imps.hpp

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// -*- C++ -*-

// Copyright (C) 2005, 2006, 2009, 2010, 2011 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the terms
// of the GNU General Public License as published by the Free Software
// Foundation; either version 3, or (at your option) any later
// version.

// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.

// Permission to use, copy, modify, sell, and distribute this software
// is hereby granted without fee, provided that the above copyright
// notice appears in all copies, and that both that copyright notice
// and this permission notice appear in supporting documentation. None
// of the above authors, nor IBM Haifa Research Laboratories, make any
// representation about the suitability of this software for any
// purpose. It is provided "as is" without express or implied
// warranty.

/**
 * @file bin_search_tree_/rotate_fn_imps.hpp
 * Contains imps for rotating nodes.
 */

PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
rotate_left(node_pointer p_x)
{
  node_pointer p_y = p_x->m_p_right;

  p_x->m_p_right = p_y->m_p_left;

  if (p_y->m_p_left != 0)
    p_y->m_p_left->m_p_parent = p_x;

  p_y->m_p_parent = p_x->m_p_parent;

  if (p_x == m_p_head->m_p_parent)
    m_p_head->m_p_parent = p_y;
  else if (p_x == p_x->m_p_parent->m_p_left)
    p_x->m_p_parent->m_p_left = p_y;
  else
    p_x->m_p_parent->m_p_right = p_y;

  p_y->m_p_left = p_x;
  p_x->m_p_parent = p_y;

  PB_DS_ASSERT_NODE_CONSISTENT(p_x)
  PB_DS_ASSERT_NODE_CONSISTENT(p_y)

  apply_update(p_x, (node_update* )this);
  apply_update(p_x->m_p_parent, (node_update* )this);
}

PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
rotate_right(node_pointer p_x)
{
  node_pointer p_y = p_x->m_p_left;

  p_x->m_p_left = p_y->m_p_right;

  if (p_y->m_p_right != 0)
    p_y->m_p_right->m_p_parent = p_x;

  p_y->m_p_parent = p_x->m_p_parent;

  if (p_x == m_p_head->m_p_parent)
    m_p_head->m_p_parent = p_y;
  else if (p_x == p_x->m_p_parent->m_p_right)
    p_x->m_p_parent->m_p_right = p_y;
  else
    p_x->m_p_parent->m_p_left = p_y;

  p_y->m_p_right = p_x;
  p_x->m_p_parent = p_y;

  PB_DS_ASSERT_NODE_CONSISTENT(p_x)
  PB_DS_ASSERT_NODE_CONSISTENT(p_y)

  apply_update(p_x, (node_update* )this);
  apply_update(p_x->m_p_parent, (node_update* )this);
}

PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
rotate_parent(node_pointer p_nd)
{
  node_pointer p_parent = p_nd->m_p_parent;

  if (p_nd == p_parent->m_p_left)
    rotate_right(p_parent);
  else
    rotate_left(p_parent);

  _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_parent = p_nd);
  _GLIBCXX_DEBUG_ASSERT(p_nd->m_p_left == p_parent ||
           p_nd->m_p_right == p_parent);
}

PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
apply_update(node_pointer /*p_nd*/, null_node_update_pointer /*p_update*/)
{ }

PB_DS_CLASS_T_DEC
template<typename Node_Update_>
inline void
PB_DS_CLASS_C_DEC::
apply_update(node_pointer p_nd, Node_Update_*  /*p_update*/)
{
  node_update::operator()(node_iterator(p_nd),
              node_const_iterator(static_cast<node_pointer>(0)));
}

PB_DS_CLASS_T_DEC
template<typename Node_Update_>
inline void
PB_DS_CLASS_C_DEC::
update_to_top(node_pointer p_nd, Node_Update_* p_update)
{
  while (p_nd != m_p_head)
    {
      apply_update(p_nd, p_update);

      p_nd = p_nd->m_p_parent;
    }
}

PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
update_to_top(node_pointer /*p_nd*/, null_node_update_pointer /*p_update*/)
{ }