lib/gl_avltree_list.c

/* Sequential list data type implemented by a binary tree.
   Copyright (C) 2006, 2008-2026 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 2006.

   This file is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.

   This file 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 Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

/* Specification.  */
#include "gl_avltree_list.h"

#include <stdlib.h>

/* -------------------------- gl_list_t Data Type -------------------------- */

/* Generic AVL tree code.  */
#include "gl_anyavltree_list1.h"

/* Generic binary tree code.  */
#include "gl_anytree_list1.h"

/* Generic AVL tree code.  */
#include "gl_anyavltree_list2.h"

/* Generic binary tree code.  */
#include "gl_anytree_list2.h"

/* For debugging.  */
static unsigned int _GL_ATTRIBUTE_PURE
check_invariants (gl_list_node_t node, gl_list_node_t parent)
{
  unsigned int left_height =
    (node->left != NULL ? check_invariants (node->left, node) : 0);
  unsigned int right_height =
    (node->right != NULL ? check_invariants (node->right, node) : 0);
  int balance = (int)right_height - (int)left_height;

  if (!(node->parent == parent))
    abort ();
  if (!(node->branch_size
        == (node->left != NULL ? node->left->branch_size : 0)
           + 1 + (node->right != NULL ? node->right->branch_size : 0)))
    abort ();
  if (!(balance >= -1 && balance <= 1))
    abort ();
  if (!(node->balance == balance))
    abort ();

  return 1 + (left_height > right_height ? left_height : right_height);
}
extern void gl_avltree_list_check_invariants (gl_list_t list);
void
gl_avltree_list_check_invariants (gl_list_t list)
{
  if (list->root != NULL)
    (void) check_invariants (list->root, NULL);
}

const struct gl_list_implementation gl_avltree_list_implementation =
  {
    gl_tree_nx_create_empty,
    gl_tree_nx_create,
    gl_tree_size,
    gl_tree_node_value,
    gl_tree_node_nx_set_value,
    gl_tree_next_node,
    gl_tree_previous_node,
    gl_tree_first_node,
    gl_tree_last_node,
    gl_tree_get_at,
    gl_tree_nx_set_at,
    gl_tree_search_from_to,
    gl_tree_indexof_from_to,
    gl_tree_nx_add_first,
    gl_tree_nx_add_last,
    gl_tree_nx_add_before,
    gl_tree_nx_add_after,
    gl_tree_nx_add_at,
    gl_tree_remove_node,
    gl_tree_remove_at,
    gl_tree_remove,
    gl_tree_list_free,
    gl_tree_iterator,
    gl_tree_iterator_from_to,
    gl_tree_iterator_next,
    gl_tree_iterator_free,
    gl_tree_sortedlist_search,
    gl_tree_sortedlist_search_from_to,
    gl_tree_sortedlist_indexof,
    gl_tree_sortedlist_indexof_from_to,
    gl_tree_sortedlist_nx_add,
    gl_tree_sortedlist_remove
  };