gtk/glib/gtree.c

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C
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1997-11-24 22:37:52 +00:00
/* GLIB - Library of useful routines for C programming
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "glib.h"
typedef struct _GRealTree GRealTree;
typedef struct _GTreeNode GTreeNode;
struct _GRealTree
{
GTreeNode *root;
GCompareFunc key_compare;
};
struct _GTreeNode
{
gint balance; /* height (left) - height (right) */
GTreeNode *left; /* left subtree */
GTreeNode *right; /* right subtree */
gpointer key; /* key for this node */
gpointer value; /* value stored at this node */
};
static GTreeNode* g_tree_node_new (gpointer key,
gpointer value);
static void g_tree_node_destroy (GTreeNode *node);
static GTreeNode* g_tree_node_insert (GTreeNode *node,
GCompareFunc compare,
gpointer key,
gpointer value,
gint *inserted);
static GTreeNode* g_tree_node_remove (GTreeNode *node,
GCompareFunc compare,
gpointer key);
static GTreeNode* g_tree_node_balance (GTreeNode *node);
static GTreeNode* g_tree_node_remove_leftmost (GTreeNode *node,
GTreeNode **leftmost);
static GTreeNode* g_tree_node_restore_left_balance (GTreeNode *node,
gint old_balance);
static GTreeNode* g_tree_node_restore_right_balance (GTreeNode *node,
gint old_balance);
static gpointer g_tree_node_lookup (GTreeNode *node,
GCompareFunc compare,
gpointer key);
static gint g_tree_node_count (GTreeNode *node);
static gint g_tree_node_pre_order (GTreeNode *node,
GTraverseFunc traverse_func,
gpointer data);
static gint g_tree_node_in_order (GTreeNode *node,
GTraverseFunc traverse_func,
gpointer data);
static gint g_tree_node_post_order (GTreeNode *node,
GTraverseFunc traverse_func,
gpointer data);
static gpointer g_tree_node_search (GTreeNode *node,
GSearchFunc search_func,
gpointer data);
static gint g_tree_node_height (GTreeNode *node);
static GTreeNode* g_tree_node_rotate_left (GTreeNode *node);
static GTreeNode* g_tree_node_rotate_right (GTreeNode *node);
static void g_tree_node_check (GTreeNode *node);
static GMemChunk *node_mem_chunk = NULL;
static GSList *node_free_list = NULL;
GTree*
g_tree_new (GCompareFunc key_compare_func)
{
GRealTree *rtree;
rtree = g_new (GRealTree, 1);
rtree->root = NULL;
rtree->key_compare = key_compare_func;
return (GTree*) rtree;
}
void
g_tree_destroy (GTree *tree)
{
GRealTree *rtree;
g_return_if_fail (tree != NULL);
rtree = (GRealTree*) tree;
g_tree_node_destroy (rtree->root);
g_free (rtree);
}
void
g_tree_insert (GTree *tree,
gpointer key,
gpointer value)
{
GRealTree *rtree;
gint inserted;
g_return_if_fail (tree != NULL);
rtree = (GRealTree*) tree;
inserted = FALSE;
rtree->root = g_tree_node_insert (rtree->root, rtree->key_compare,
key, value, &inserted);
}
void
g_tree_remove (GTree *tree,
gpointer key)
{
GRealTree *rtree;
g_return_if_fail (tree != NULL);
rtree = (GRealTree*) tree;
rtree->root = g_tree_node_remove (rtree->root, rtree->key_compare, key);
}
gpointer
g_tree_lookup (GTree *tree,
gpointer key)
{
GRealTree *rtree;
g_return_val_if_fail (tree != NULL, NULL);
rtree = (GRealTree*) tree;
return g_tree_node_lookup (rtree->root, rtree->key_compare, key);
}
void
g_tree_traverse (GTree *tree,
GTraverseFunc traverse_func,
GTraverseType traverse_type,
gpointer data)
{
GRealTree *rtree;
g_return_if_fail (tree != NULL);
rtree = (GRealTree*) tree;
g_return_if_fail (rtree->root != NULL);
switch (traverse_type)
{
case G_PRE_ORDER:
g_tree_node_pre_order (rtree->root, traverse_func, data);
break;
case G_IN_ORDER:
g_tree_node_in_order (rtree->root, traverse_func, data);
break;
case G_POST_ORDER:
g_tree_node_post_order (rtree->root, traverse_func, data);
break;
}
}
gpointer
g_tree_search (GTree *tree,
GSearchFunc search_func,
gpointer data)
{
GRealTree *rtree;
g_return_val_if_fail (tree != NULL, NULL);
rtree = (GRealTree*) tree;
if (rtree->root)
return g_tree_node_search (rtree->root, search_func, data);
return NULL;
}
gint
g_tree_height (GTree *tree)
{
GRealTree *rtree;
g_return_val_if_fail (tree != NULL, 0);
rtree = (GRealTree*) tree;
if (rtree->root)
return g_tree_node_height (rtree->root);
return 0;
}
gint
g_tree_nnodes (GTree *tree)
{
GRealTree *rtree;
g_return_val_if_fail (tree != NULL, 0);
rtree = (GRealTree*) tree;
if (rtree->root)
return g_tree_node_count (rtree->root);
return 0;
}
static GTreeNode*
g_tree_node_new (gpointer key,
gpointer value)
{
GTreeNode *node;
GSList *tmp_list;
if (node_free_list)
{
tmp_list = node_free_list;
node_free_list = node_free_list->next;
node = tmp_list->data;
{
GListAllocator *tmp_allocator = g_list_set_allocator (NULL);
g_slist_free_1 (tmp_list);
g_list_set_allocator (tmp_allocator);
}
}
else
{
if (!node_mem_chunk)
node_mem_chunk = g_mem_chunk_new ("tree node mem chunk", sizeof (GTreeNode), 1024, G_ALLOC_ONLY);
node = g_chunk_new (GTreeNode, node_mem_chunk);
}
node->balance = 0;
node->left = NULL;
node->right = NULL;
node->key = key;
node->value = value;
return node;
}
static void
g_tree_node_destroy (GTreeNode *node)
{
if (node)
{
node_free_list = g_slist_prepend (node_free_list, node);
g_tree_node_destroy (node->right);
g_tree_node_destroy (node->left);
}
}
static GTreeNode*
g_tree_node_insert (GTreeNode *node,
GCompareFunc compare,
gpointer key,
gpointer value,
gint *inserted)
{
gint old_balance;
gint cmp;
if (!node)
{
*inserted = TRUE;
return g_tree_node_new (key, value);
}
cmp = (* compare) (key, node->key);
if (cmp == 0)
{
*inserted = FALSE;
node->value = value;
return node;
}
if (cmp < 0)
{
if (node->left)
{
old_balance = node->left->balance;
node->left = g_tree_node_insert (node->left, compare, key, value, inserted);
if ((old_balance != node->left->balance) && node->left->balance)
node->balance -= 1;
}
else
{
*inserted = TRUE;
node->left = g_tree_node_new (key, value);
node->balance -= 1;
}
}
else if (cmp > 0)
{
if (node->right)
{
old_balance = node->right->balance;
node->right = g_tree_node_insert (node->right, compare, key, value, inserted);
if ((old_balance != node->right->balance) && node->right->balance)
node->balance += 1;
}
else
{
*inserted = TRUE;
node->right = g_tree_node_new (key, value);
node->balance += 1;
}
}
if (*inserted)
{
if ((node->balance < -1) || (node->balance > 1))
node = g_tree_node_balance (node);
}
return node;
}
static GTreeNode*
g_tree_node_remove (GTreeNode *node,
GCompareFunc compare,
gpointer key)
{
GTreeNode *garbage;
GTreeNode *new_root;
gint old_balance;
gint cmp;
if (!node)
return NULL;
cmp = (* compare) (key, node->key);
if (cmp == 0)
{
garbage = node;
if (!node->right)
{
node = node->left;
}
else
{
old_balance = node->right->balance;
node->right = g_tree_node_remove_leftmost (node->right, &new_root);
new_root->left = node->left;
new_root->right = node->right;
new_root->balance = node->balance;
node = g_tree_node_restore_right_balance (new_root, old_balance);
}
node_free_list = g_slist_prepend (node_free_list, garbage);
}
else if (cmp < 0)
{
if (node->left)
{
old_balance = node->left->balance;
node->left = g_tree_node_remove (node->left, compare, key);
node = g_tree_node_restore_left_balance (node, old_balance);
}
}
else if (cmp > 0)
{
if (node->right)
{
old_balance = node->right->balance;
node->right = g_tree_node_remove (node->right, compare, key);
node = g_tree_node_restore_right_balance (node, old_balance);
}
}
return node;
}
static GTreeNode*
g_tree_node_balance (GTreeNode *node)
{
if (node->balance < -1)
{
if (node->left->balance > 0)
node->left = g_tree_node_rotate_left (node->left);
node = g_tree_node_rotate_right (node);
}
else if (node->balance > 1)
{
if (node->right->balance < 0)
node->right = g_tree_node_rotate_right (node->right);
node = g_tree_node_rotate_left (node);
}
return node;
}
static GTreeNode*
g_tree_node_remove_leftmost (GTreeNode *node,
GTreeNode **leftmost)
{
gint old_balance;
if (!node->left)
{
*leftmost = node;
return node->right;
}
old_balance = node->left->balance;
node->left = g_tree_node_remove_leftmost (node->left, leftmost);
return g_tree_node_restore_left_balance (node, old_balance);
}
static GTreeNode*
g_tree_node_restore_left_balance (GTreeNode *node,
gint old_balance)
{
if (!node->left)
node->balance += 1;
else if ((node->left->balance != old_balance) &&
(node->left->balance == 0))
node->balance += 1;
if (node->balance > 1)
return g_tree_node_balance (node);
return node;
}
static GTreeNode*
g_tree_node_restore_right_balance (GTreeNode *node,
gint old_balance)
{
if (!node->right)
node->balance -= 1;
else if ((node->right->balance != old_balance) &&
(node->right->balance == 0))
node->balance -= 1;
if (node->balance < -1)
return g_tree_node_balance (node);
return node;
}
static gpointer
g_tree_node_lookup (GTreeNode *node,
GCompareFunc compare,
gpointer key)
{
gint cmp;
if (!node)
return NULL;
cmp = (* compare) (key, node->key);
if (cmp == 0)
return node->value;
if (cmp < 0)
{
if (node->left)
return g_tree_node_lookup (node->left, compare, key);
}
else if (cmp > 0)
{
if (node->right)
return g_tree_node_lookup (node->right, compare, key);
}
return NULL;
}
static gint
g_tree_node_count (GTreeNode *node)
{
gint count;
count = 1;
if (node->left)
count += g_tree_node_count (node->left);
if (node->right)
count += g_tree_node_count (node->right);
return count;
}
static gint
g_tree_node_pre_order (GTreeNode *node,
GTraverseFunc traverse_func,
gpointer data)
{
if ((*traverse_func) (node->key, node->value, data))
return TRUE;
if (node->left)
{
if (g_tree_node_pre_order (node->left, traverse_func, data))
return TRUE;
}
if (node->right)
{
if (g_tree_node_pre_order (node->right, traverse_func, data))
return TRUE;
}
return FALSE;
}
static gint
g_tree_node_in_order (GTreeNode *node,
GTraverseFunc traverse_func,
gpointer data)
{
if (node->left)
{
if (g_tree_node_in_order (node->left, traverse_func, data))
return TRUE;
}
if ((*traverse_func) (node->key, node->value, data))
return TRUE;
if (node->right)
{
if (g_tree_node_in_order (node->right, traverse_func, data))
return TRUE;
}
return FALSE;
}
static gint
g_tree_node_post_order (GTreeNode *node,
GTraverseFunc traverse_func,
gpointer data)
{
if (node->left)
{
if (g_tree_node_post_order (node->left, traverse_func, data))
return TRUE;
}
if (node->right)
{
if (g_tree_node_post_order (node->right, traverse_func, data))
return TRUE;
}
if ((*traverse_func) (node->key, node->value, data))
return TRUE;
return FALSE;
}
static gpointer
g_tree_node_search (GTreeNode *node,
GSearchFunc search_func,
gpointer data)
{
gint dir;
if (!node)
return NULL;
do {
dir = (* search_func) (node->key, data);
if (dir == 0)
return node->value;
if (dir < 0)
node = node->left;
else if (dir > 0)
node = node->right;
} while (node && (dir != 0));
return NULL;
}
static gint
g_tree_node_height (GTreeNode *node)
{
gint left_height;
gint right_height;
if (node)
{
left_height = 0;
right_height = 0;
if (node->left)
left_height = g_tree_node_height (node->left);
if (node->right)
right_height = g_tree_node_height (node->right);
return MAX (left_height, right_height) + 1;
}
return 0;
}
static GTreeNode*
g_tree_node_rotate_left (GTreeNode *node)
{
GTreeNode *left;
GTreeNode *right;
gint a_bal;
gint b_bal;
left = node->left;
right = node->right;
node->right = right->left;
right->left = node;
a_bal = node->balance;
b_bal = right->balance;
if (b_bal <= 0)
{
if (a_bal >= 1)
right->balance = b_bal - 1;
else
right->balance = a_bal + b_bal - 2;
node->balance = a_bal - 1;
}
else
{
if (a_bal <= b_bal)
right->balance = a_bal - 2;
else
right->balance = b_bal - 1;
node->balance = a_bal - b_bal - 1;
}
return right;
}
static GTreeNode*
g_tree_node_rotate_right (GTreeNode *node)
{
GTreeNode *left;
GTreeNode *right;
gint a_bal;
gint b_bal;
left = node->left;
right = node->right;
node->left = left->right;
left->right = node;
a_bal = node->balance;
b_bal = left->balance;
if (b_bal <= 0)
{
if (b_bal > a_bal)
left->balance = b_bal + 1;
else
left->balance = a_bal + 2;
node->balance = a_bal - b_bal + 1;
}
else
{
if (a_bal <= -1)
left->balance = b_bal + 1;
else
left->balance = a_bal + b_bal + 2;
node->balance = a_bal + 1;
}
return left;
}
static void
g_tree_node_check (GTreeNode *node)
{
gint left_height;
gint right_height;
gint balance;
if (node)
{
left_height = 0;
right_height = 0;
if (node->left)
left_height = g_tree_node_height (node->left);
if (node->right)
right_height = g_tree_node_height (node->right);
balance = right_height - left_height;
if (balance != node->balance)
g_print ("g_tree_node_check: failed: %d ( %d )\n",
balance, node->balance);
if (node->left)
g_tree_node_check (node->left);
if (node->right)
g_tree_node_check (node->right);
}
}