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;
}
/* internal remove routine */
static gboolean
g_tree_remove_internal (GTree *tree,
gconstpointer key,
gboolean steal)
{
GTreeNode *node, *parent, *balance;
GTreeNode *path[MAX_GTREE_HEIGHT];
int idx;
gboolean left_node;
g_return_val_if_fail (tree != NULL, FALSE);
if (!tree->root)
return FALSE;
idx = 0;
path[idx++] = NULL;
node = tree->root;
while (1)
{
int cmp = tree->key_compare (key, node->key, tree->key_compare_data);
if (cmp == 0)
break;
else if (cmp < 0)
{
if (!node->left_child)
return FALSE;
path[idx++] = node;
node = node->left;
}
else
{
if (!node->right_child)
return FALSE;
path[idx++] = node;
node = node->right;
}
}
/* The following code is almost equal to g_tree_remove_node,
* except that we do not have to call g_tree_node_parent.
*/
balance = parent = path[--idx];
g_assert (!parent || parent->left == node || parent->right == node);
left_node = (parent && node == parent->left);
if (!node->left_child)
{
if (!node->right_child)
{
if (!parent)
tree->root = NULL;
else if (left_node)
{
parent->left_child = FALSE;
parent->left = node->left;
parent->balance += 1;
}
else
{
parent->right_child = FALSE;
parent->right = node->right;
parent->balance -= 1;
}
}
else /* node has a right child */
{
GTreeNode *tmp = g_tree_node_next (node);
tmp->left = node->left;
if (!parent)
tree->root = node->right;
else if (left_node)
{
parent->left = node->right;
parent->balance += 1;
}
else
{
parent->right = node->right;
parent->balance -= 1;
}
}
}
else /* node has a left child */
{
if (!node->right_child)
{
GTreeNode *tmp = g_tree_node_previous (node);
tmp->right = node->right;
if (parent == NULL)
tree->root = node->left;
else if (left_node)
{
parent->left = node->left;
parent->balance += 1;
}
else
{
parent->right = node->left;
parent->balance -= 1;
}
}
else /* node has a both children (pant, pant!) */
{
GTreeNode *prev = node->left;
GTreeNode *next = node->right;
GTreeNode *nextp = node;
int old_idx = idx + 1;
idx++;
/* path[idx] == parent */
/* find the immediately next node (and its parent) */
while (next->left_child)
{
path[++idx] = nextp = next;
next = next->left;
}
path[old_idx] = next;
balance = path[idx];
/* remove 'next' from the tree */
if (nextp != node)
{
if (next->right_child)
nextp->left = next->right;
else
nextp->left_child = FALSE;
nextp->balance += 1;
next->right_child = TRUE;
next->right = node->right;
}
else
node->balance -= 1;
/* set the prev to point to the right place */
while (prev->right_child)
prev = prev->right;
prev->right = next;
/* prepare 'next' to replace 'node' */
next->left_child = TRUE;
next->left = node->left;
next->balance = node->balance;
if (!parent)
tree->root = next;
else if (left_node)
parent->left = next;
else
parent->right = next;
}
}
/* restore balance */
if (balance)
while (1)
{
GTreeNode *bparent = path[--idx];
g_assert (!bparent || bparent->left == balance || bparent->right == balance);
left_node = (bparent && balance == bparent->left);
if(balance->balance < -1 || balance->balance > 1)
{
balance = g_tree_node_balance (balance);
if (!bparent)
tree->root = balance;
else if (left_node)
bparent->left = balance;
else
bparent->right = balance;
}
if (balance->balance != 0 || !bparent)
break;
if (left_node)
bparent->balance += 1;
else
bparent->balance -= 1;
balance = bparent;
}
if (!steal)
{
if (tree->key_destroy_func)
tree->key_destroy_func (node->key);
if (tree->value_destroy_func)
tree->value_destroy_func (node->value);
}
g_slice_free (GTreeNode, node);
tree->nnodes--;
return TRUE;
}
/* internal insert routine */
static void
g_tree_insert_internal (GTree *tree,
gpointer key,
gpointer value,
gboolean replace)
{
GTreeNode *node;
GTreeNode *path[MAX_GTREE_HEIGHT];
int idx;
g_return_if_fail (tree != NULL);
if (!tree->root)
{
tree->root = g_tree_node_new (key, value);
tree->nnodes++;
return;
}
idx = 0;
path[idx++] = NULL;
node = tree->root;
while (1)
{
int cmp = tree->key_compare (key, node->key, tree->key_compare_data);
if (cmp == 0)
{
if (tree->value_destroy_func)
tree->value_destroy_func (node->value);
node->value = value;
if (replace)
{
if (tree->key_destroy_func)
tree->key_destroy_func (node->key);
node->key = key;
}
else
{
/* free the passed key */
if (tree->key_destroy_func)
tree->key_destroy_func (key);
}
return;
}
else if (cmp < 0)
{
if (node->left_child)
{
path[idx++] = node;
node = node->left;
}
else
{
GTreeNode *child = g_tree_node_new (key, value);
child->left = node->left;
child->right = node;
node->left = child;
node->left_child = TRUE;
node->balance -= 1;
tree->nnodes++;
break;
}
}
else
{
if (node->right_child)
{
path[idx++] = node;
node = node->right;
}
else
{
GTreeNode *child = g_tree_node_new (key, value);
child->right = node->right;
child->left = node;
node->right = child;
node->right_child = TRUE;
node->balance += 1;
tree->nnodes++;
break;
}
}
}
/* Restore balance. This is the goodness of a non-recursive
* implementation, when we are done with balancing we 'break'
* the loop and we are done.
*/
while (1)
{
GTreeNode *bparent = path[--idx];
gboolean left_node = (bparent && node == bparent->left);
g_assert (!bparent || bparent->left == node || bparent->right == node);
if (node->balance < -1 || node->balance > 1)
{
node = g_tree_node_balance (node);
if (bparent == NULL)
tree->root = node;
else if (left_node)
bparent->left = node;
else
bparent->right = node;
}
if (node->balance == 0 || bparent == NULL)
break;
if (left_node)
bparent->balance -= 1;
else
bparent->balance += 1;
node = bparent;
}
}
static GTreeNode*
g_tree_node_insert (GTree *tree,
GTreeNode *node,
gpointer key,
gpointer value,
gboolean replace,
gboolean *inserted)
{
gint old_balance;
gint cmp;
if (!node)
{
*inserted = TRUE;
return g_tree_node_new (key, value);
}
cmp = tree->key_compare (key, node->key, tree->key_compare_data);
if (cmp == 0)
{
*inserted = FALSE;
if (tree->value_destroy_func)
tree->value_destroy_func (node->value);
node->value = value;
if (replace)
{
if (tree->key_destroy_func)
tree->key_destroy_func (node->key);
node->key = key;
}
else
{
/* free the passed key */
if (tree->key_destroy_func)
tree->key_destroy_func (key);
}
return node;
}
if (cmp < 0)
{
if (node->left)
{
old_balance = node->left->balance;
node->left = g_tree_node_insert (tree,
node->left,
key, value,
replace, 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 (tree,
node->right,
key, value,
replace, 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;
}
