/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Copyright (c) 1996,1997
 * Silicon Graphics Computer Systems, Inc.
 *
 * Copyright (c) 1997
 * Moscow Center for SPARC Technology
 *
 * Copyright (c) 1999 
 * Boris Fomitchev
 *
 * This material is provided "as is", with absolutely no warranty expressed
 * or implied. Any use is at your own risk.
 *
 * Permission to use or copy this software for any purpose is hereby granted 
 * without fee, provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 *
 */

/* NOTE: This is an internal header file, included by other STL headers.
 *   You should not attempt to use it directly.
 */

#ifndef __SGI_STL_INTERNAL_TREE_H
#define __SGI_STL_INTERNAL_TREE_H

/*

Red-black tree class, designed for use in implementing STL
associative containers (set, multiset, map, and multimap). The
insertion and deletion algorithms are based on those in Cormen,
Leiserson, and Rivest, Introduction to Algorithms (MIT Press, 1990),
except that

(1) the header cell is maintained with links not only to the root
but also to the leftmost node of the tree, to enable constant time
begin(), and to the rightmost node of the tree, to enable linear time
performance when used with the generic set algorithms (set_union,
etc.);

(2) when a node being deleted has two children its successor node is
relinked into its place, rather than copied, so that the only
iterators invalidated are those referring to the deleted node.

*/

# ifndef __SGI_STL_INTERNAL_ALGOBASE_H
#  include <stl_algobase.h>
# endif

# ifndef __SGI_STL_INTERNAL_ALLOC_H
#  include <stl_alloc.h>
# endif

# ifndef __SGI_STL_INTERNAL_ITERATOR_H
#  include <stl_iterator.h>
# endif

# ifndef __SGI_STL_INTERNAL_CONSTRUCT_H
#  include <stl_construct.h>
# endif

# ifndef __SGI_STL_INTERNAL_FUNSTION_H
#  include <stl_function.h>
# endif

# if defined ( __STL_USE_ABBREVS )
// ugliness is intentional - to reduce conflicts possibility
#  define _Rb_tree_node_base       _rbT__NB
#  define _Rb_tree_node            _rbT__N
#  define _Rb_base_iterator        _rbTB__It
#  define _Rb_tree_base_iterator   _rbT__It
#  define _Rb_tree_base            _rbT__B
# endif

__STL_BEGIN_NAMESPACE

#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)
#pragma set woff 1375
#endif

# if defined (__STL_DEBUG)
#   define _Make_iterator(__l) iterator(&_M_iter_list,__l) 
#   define _Make_const_iterator(__l) const_iterator(&_M_iter_list,__l)
# else
#   define _Make_iterator iterator
#   define _Make_const_iterator const_iterator
# endif

typedef bool _Rb_tree_Color_type;
const _Rb_tree_Color_type _S_rb_tree_red = false;
const _Rb_tree_Color_type _S_rb_tree_black = true;

struct _Rb_tree_node_base
{
  typedef _Rb_tree_Color_type _Color_type;
  typedef _Rb_tree_node_base* _Base_ptr;

  _Color_type _M_color; 
  _Base_ptr _M_parent;
  _Base_ptr _M_left;
  _Base_ptr _M_right;

  static _Base_ptr _S_minimum(_Base_ptr __x)
  {
    while (__x->_M_left != 0) __x = __x->_M_left;
    return __x;
  }

  static _Base_ptr _S_maximum(_Base_ptr __x)
  {
    while (__x->_M_right != 0) __x = __x->_M_right;
    return __x;
  }
};

template <class _Value>
struct _Rb_tree_node : public _Rb_tree_node_base
{
  _Value _M_value_field;
  __TRIVIAL_STUFF(_Rb_tree_node)
};

struct _Rb_tree_base_iterator;

template <class _Dummy>
struct _Rb_global {
  typedef _Rb_tree_node_base* _Base_ptr;
  // those used to be global functions 
  static void _Rebalance(_Rb_tree_node_base* __x, _Rb_tree_node_base*& __root);
  static _Rb_tree_node_base* _Rebalance_for_erase(_Rb_tree_node_base* __z,
						  _Rb_tree_node_base*& __root,
						  _Rb_tree_node_base*& __leftmost,
						  _Rb_tree_node_base*& __rightmost);
  // those are from _Rb_tree_base_iterator - moved here to reduce code bloat
  // moved here to reduce code bloat without templatizing _Rb_tree_base_iterator
  static void _M_increment(_Rb_tree_base_iterator*);
  static void _M_decrement(_Rb_tree_base_iterator*);
};

typedef _Rb_global<bool> _Rb_global_inst;

struct _Rb_tree_base_iterator
# if defined ( __STL_DEBUG )
    : public __owned_link 
# endif
{
  typedef _Rb_tree_node_base::_Base_ptr _Base_ptr;
  typedef bidirectional_iterator_tag iterator_category;
  typedef ptrdiff_t difference_type;
  _Base_ptr _M_node;
# if defined ( __STL_DEBUG )
  _Base_ptr _Owner_node() const {
      const __owned_list* __ptr = _Owner();
      return __ptr ? _Base_ptr(__ptr->_Owner()) : _Base_ptr(0); 
  }
  _Rb_tree_base_iterator() : __owned_link(0) {}
  _Rb_tree_base_iterator(const __owned_list* __root, _Base_ptr __p) : 
      __owned_link(__root), _M_node(__p) {}
# endif

};

inline bool operator==(const _Rb_tree_base_iterator& __x,
                       const _Rb_tree_base_iterator& __y) {
  return __x._M_node == __y._M_node;
}

inline bool operator!=(const _Rb_tree_base_iterator& __x,
                       const _Rb_tree_base_iterator& __y) {
  return __x._M_node != __y._M_node;
}


template <class _Value, class _Traits>
struct _Rb_tree_iterator : public _Rb_tree_base_iterator
{
  typedef _Value value_type;
  typedef typename _Traits::reference  reference;
  typedef typename _Traits::pointer    pointer;
  
  typedef _Rb_tree_iterator<_Value, _Nonconst_traits<_Value> >  iterator;
  typedef _Rb_tree_iterator<_Value, _Const_traits<_Value> > const_iterator;
  typedef _Rb_tree_iterator<_Value, _Traits> _Self;
  typedef _Rb_tree_node<_Value>* _Link_type;

  //  operator const const_iterator& () const { return *(const const_iterator*)this; } 

  _Rb_tree_iterator() {}
# if defined ( __STL_DEBUG )
  _Rb_tree_iterator(const __owned_list* __root, _Link_type __x) :
    _Rb_tree_base_iterator(__root,__x) {}
  _Rb_tree_iterator(const iterator& __it) : 
    _Rb_tree_base_iterator(__it._Owner(),__it._M_node) {}
# else
  _Rb_tree_iterator(_Link_type __x) { _M_node = __x; }
  _Rb_tree_iterator(const iterator& __it) { _M_node = __it._M_node; }
# endif

  reference operator*() const { 
    __stl_verbose_assert(_M_node!=_Owner_node(), _StlMsg_NOT_DEREFERENCEABLE); 
    return _Link_type(_M_node)->_M_value_field; 
  }
  
  __STL_DEFINE_ARROW_OPERATOR

  _Self& operator++() { _Rb_global_inst::_M_increment(this); return *this; }
  _Self operator++(int) {
    _Self __tmp = *this;
    _Rb_global_inst::_M_increment(this);
    return __tmp;
  }
    
  _Self& operator--() { _Rb_global_inst::_M_decrement(this); return *this; }
  _Self operator--(int) {
    _Self __tmp = *this;
    _Rb_global_inst::_M_decrement(this);
    return __tmp;
  }
};

# ifndef __STL_CLASS_PARTIAL_SPECIALIZATION


template <class _Value, class _Traits>
inline _Value*
value_type(const _Rb_tree_iterator<_Value, _Traits>&) {
  return (_Value*)0;
}


inline bidirectional_iterator_tag
iterator_category(const _Rb_tree_base_iterator&) {
  return bidirectional_iterator_tag();
}

inline ptrdiff_t*
distance_type(const _Rb_tree_base_iterator&) {
  return (ptrdiff_t*) 0;
}

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

// Base class to help EH

template <class _Tp, class _Alloc>
struct _Rb_tree_base
{
  typedef _Rb_tree_node<_Tp> _Node;
  typedef typename _Alloc_traits<_Tp, _Alloc>::allocator_type allocator_type;

  _Rb_tree_base(const allocator_type& __a) : 
    _M_header(__STL_CONVERT_ALLOCATOR(__a, _Node), (_Node*)0) { 
      _M_header._M_data = _M_header.allocate(1); 
      __stl_debug_do(_M_iter_list._Safe_init(_M_header._M_data));
  }
  ~_Rb_tree_base() { 
    __stl_debug_do(_M_iter_list._Invalidate());
    _M_header.deallocate(_M_header._M_data,1); 
  }
  allocator_type get_allocator() const { 
    return __STL_CONVERT_ALLOCATOR(_M_header, _Tp); 
  }
protected:
  typedef typename _Alloc_traits<_Node, _Alloc>::allocator_type _M_node_allocator_type;
  _STL_alloc_proxy<_Node*, _Node, _M_node_allocator_type> _M_header;
  
# if defined (__STL_DEBUG)
protected:
    friend class __owned_link;
    mutable __owned_list _M_iter_list;
public:
    void _Invalidate_all() {_M_iter_list._Invalidate_all();}
# endif
};


template <class _Key, class _Value, class _KeyOfValue, class _Compare,
          __STL_DEFAULT_ALLOCATOR_SELECT(_Value) >
class _Rb_tree : protected _Rb_tree_base<_Value, _Alloc> {
  typedef _Rb_tree_base<_Value, _Alloc> _Base;
protected:
  typedef _Rb_tree_node_base* _Base_ptr;
  typedef _Rb_tree_node<_Value> _Node;
  typedef _Rb_tree_Color_type _Color_type;
public:
  typedef _Key key_type;
  typedef _Value value_type;
  typedef value_type* pointer;
  typedef const value_type* const_pointer;
  typedef value_type& reference;
  typedef const value_type& const_reference;
  typedef _Rb_tree_node<_Value>* _Link_type;
  typedef size_t size_type;
  typedef ptrdiff_t difference_type;

  typedef typename _Base::allocator_type allocator_type;
  __STL_USING_BASE_MEMBER _Rb_tree_base<_Value, _Alloc>::get_allocator;

protected:
#if defined( __STL_HAS_NAMESPACES )
  __STL_USING_BASE_MEMBER _Rb_tree_base<_Value, _Alloc>::_M_header;
#endif /* __STL_USE_NAMESPACES */

protected:

  _Link_type _M_create_node(const value_type& __x)
  {
    _Link_type __tmp = _M_header.allocate(1);
    __STL_TRY {
      construct(&__tmp->_M_value_field, __x);
    }
    __STL_UNWIND(_M_header.deallocate(__tmp,1));
    return __tmp;
  }

  _Link_type _M_clone_node(_Link_type __x)
  {
    _Link_type __tmp = _M_create_node(__x->_M_value_field);
    __tmp->_M_color = __x->_M_color;
    __tmp->_M_left = 0;
    __tmp->_M_right = 0;
    return __tmp;
  }

  void destroy_node(_Link_type __p)
  {
    destroy(&__p->_M_value_field);
    _M_header.deallocate(__p,1);
  }

protected:
  size_type _M_node_count; // keeps track of size of tree
  _Compare _M_key_compare;

  _Link_type& _M_root() const