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+/* 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 Lesser 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/*
+ * Modified by the GLib Team and others 1997-2000. See the AUTHORS
+ * file for a list of people on the GLib Team. See the ChangeLog
+ * files for a list of changes. These files are distributed with
+ * GLib at ftp://ftp.gtk.org/pub/gtk/.
+ */
+
+/*
+ * MT safe
+ */
+
+#include "config.h"
+
+#include "gtree.h"
+
+#include "gatomic.h"
+#include "gtestutils.h"
+#include "gslice.h"
+
+/**
+ * SECTION:trees-binary
+ * @title: Balanced Binary Trees
+ * @short_description: a sorted collection of key/value pairs optimized
+ * for searching and traversing in order
+ *
+ * The #GTree structure and its associated functions provide a sorted
+ * collection of key/value pairs optimized for searching and traversing
+ * in order.
+ *
+ * To create a new #GTree use g_tree_new().
+ *
+ * To insert a key/value pair into a #GTree use g_tree_insert().
+ *
+ * To lookup the value corresponding to a given key, use
+ * g_tree_lookup() and g_tree_lookup_extended().
+ *
+ * To find out the number of nodes in a #GTree, use g_tree_nnodes(). To
+ * get the height of a #GTree, use g_tree_height().
+ *
+ * To traverse a #GTree, calling a function for each node visited in
+ * the traversal, use g_tree_foreach().
+ *
+ * To remove a key/value pair use g_tree_remove().
+ *
+ * To destroy a #GTree, use g_tree_destroy().
+ **/
+
+#undef G_TREE_DEBUG
+
+#define MAX_GTREE_HEIGHT 40
+
+typedef struct _GTreeNode GTreeNode;
+
+/**
+ * GTree:
+ *
+ * The <structname>GTree</structname> struct is an opaque data
+ * structure representing a <link
+ * linkend="glib-Balanced-Binary-Trees">Balanced Binary Tree</link>. It
+ * should be accessed only by using the following functions.
+ **/
+struct _GTree
+{
+ GTreeNode *root;
+ GCompareDataFunc key_compare;
+ GDestroyNotify key_destroy_func;
+ GDestroyNotify value_destroy_func;
+ gpointer key_compare_data;
+ guint nnodes;
+ gint ref_count;
+};
+
+struct _GTreeNode
+{
+ gpointer key; /* key for this node */
+ gpointer value; /* value stored at this node */
+ GTreeNode *left; /* left subtree */
+ GTreeNode *right; /* right subtree */
+ gint8 balance; /* height (right) - height (left) */
+ guint8 left_child;
+ guint8 right_child;
+};
+
+
+static GTreeNode* g_tree_node_new (gpointer key,
+ gpointer value);
+static void g_tree_insert_internal (GTree *tree,
+ gpointer key,
+ gpointer value,
+ gboolean replace);
+static gboolean g_tree_remove_internal (GTree *tree,
+ gconstpointer key,
+ gboolean steal);
+static GTreeNode* g_tree_node_balance (GTreeNode *node);
+static GTreeNode *g_tree_find_node (GTree *tree,
+ gconstpointer key);
+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,
+ GCompareFunc search_func,
+ gconstpointer data);
+static GTreeNode* g_tree_node_rotate_left (GTreeNode *node);
+static GTreeNode* g_tree_node_rotate_right (GTreeNode *node);
+#ifdef G_TREE_DEBUG
+static void g_tree_node_check (GTreeNode *node);
+#endif
+
+
+static GTreeNode*
+g_tree_node_new (gpointer key,
+ gpointer value)
+{
+ GTreeNode *node = g_slice_new (GTreeNode);
+
+ node->balance = 0;
+ node->left = NULL;
+ node->right = NULL;
+ node->left_child = FALSE;
+ node->right_child = FALSE;
+ node->key = key;
+ node->value = value;
+
+ return node;
+}
+
+/**
+ * g_tree_new:
+ * @key_compare_func: the function used to order the nodes in the #GTree.
+ * It should return values similar to the standard strcmp() function -
+ * 0 if the two arguments are equal, a negative value if the first argument
+ * comes before the second, or a positive value if the first argument comes
+ * after the second.
+ *
+ * Creates a new #GTree.
+ *
+ * Return value: a new #GTree.
+ **/
+GTree*
+g_tree_new (GCompareFunc key_compare_func)
+{
+ g_return_val_if_fail (key_compare_func != NULL, NULL);
+
+ return g_tree_new_full ((GCompareDataFunc) key_compare_func, NULL,
+ NULL, NULL);
+}
+
+/**
+ * g_tree_new_with_data:
+ * @key_compare_func: qsort()-style comparison function.
+ * @key_compare_data: data to pass to comparison function.
+ *
+ * Creates a new #GTree with a comparison function that accepts user data.
+ * See g_tree_new() for more details.
+ *
+ * Return value: a new #GTree.
+ **/
+GTree*
+g_tree_new_with_data (GCompareDataFunc key_compare_func,
+ gpointer key_compare_data)
+{
+ g_return_val_if_fail (key_compare_func != NULL, NULL);
+
+ return g_tree_new_full (key_compare_func, key_compare_data,
+ NULL, NULL);
+}
+
+/**
+ * g_tree_new_full:
+ * @key_compare_func: qsort()-style comparison function.
+ * @key_compare_data: data to pass to comparison function.
+ * @key_destroy_func: a function to free the memory allocated for the key
+ * used when removing the entry from the #GTree or %NULL if you don't
+ * want to supply such a function.
+ * @value_destroy_func: a function to free the memory allocated for the
+ * value used when removing the entry from the #GTree or %NULL if you
+ * don't want to supply such a function.
+ *
+ * Creates a new #GTree like g_tree_new() and allows to specify functions
+ * to free the memory allocated for the key and value that get called when
+ * removing the entry from the #GTree.
+ *
+ * Return value: a new #GTree.
+ **/
+GTree*
+g_tree_new_full (GCompareDataFunc key_compare_func,
+ gpointer key_compare_data,
+ GDestroyNotify key_destroy_func,
+ GDestroyNotify value_destroy_func)
+{
+ GTree *tree;
+
+ g_return_val_if_fail (key_compare_func != NULL, NULL);
+
+ tree = g_slice_new (GTree);
+ tree->root = NULL;
+ tree->key_compare = key_compare_func;
+ tree->key_destroy_func = key_destroy_func;
+ tree->value_destroy_func = value_destroy_func;
+ tree->key_compare_data = key_compare_data;
+ tree->nnodes = 0;
+ tree->ref_count = 1;
+
+ return tree;
+}
+
+static inline GTreeNode *
+g_tree_first_node (GTree *tree)
+{
+ GTreeNode *tmp;
+
+ if (!tree->root)
+ return NULL;
+
+ tmp = tree->root;
+
+ while (tmp->left_child)
+ tmp = tmp->left;
+
+ return tmp;
+}
+
+static inline GTreeNode *
+g_tree_node_previous (GTreeNode *node)
+{
+ GTreeNode *tmp;
+
+ tmp = node->left;
+
+ if (node->left_child)
+ while (tmp->right_child)
+ tmp = tmp->right;
+
+ return tmp;
+}
+
+static inline GTreeNode *
+g_tree_node_next (GTreeNode *node)
+{
+ GTreeNode *tmp;
+
+ tmp = node->right;
+
+ if (node->right_child)
+ while (tmp->left_child)
+ tmp = tmp->left;
+
+ return tmp;
+}
+
+static void
+g_tree_remove_all (GTree *tree)
+{
+ GTreeNode *node;
+ GTreeNode *next;
+
+ g_return_if_fail (tree != NULL);
+
+ node = g_tree_first_node (tree);
+
+ while (node)
+ {
+ next = g_tree_node_next (node);
+
+ 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);
+
+ node = next;
+ }
+
+ tree->root = NULL;
+ tree->nnodes = 0;
+}
+
+/**
+ * g_tree_ref:
+ * @tree: a #GTree.
+ *
+ * Increments the reference count of @tree by one. It is safe to call
+ * this function from any thread.
+ *
+ * Return value: the passed in #GTree.
+ *
+ * Since: 2.22
+ **/
+GTree *
+g_tree_ref (GTree *tree)
+{
+ g_return_val_if_fail (tree != NULL, NULL);
+
+ g_atomic_int_inc (&tree->ref_count);
+
+ return tree;
+}
+
+/**
+ * g_tree_unref:
+ * @tree: a #GTree.
+ *
+ * Decrements the reference count of @tree by one. If the reference count
+ * drops to 0, all keys and values will be destroyed (if destroy
+ * functions were specified) and all memory allocated by @tree will be
+ * released.
+ *
+ * It is safe to call this function from any thread.
+ *
+ * Since: 2.22
+ **/
+void
+g_tree_unref (GTree *tree)
+{
+ g_return_if_fail (tree != NULL);
+
+ if (g_atomic_int_dec_and_test (&tree->ref_count))
+ {
+ g_tree_remove_all (tree);
+ g_slice_free (GTree, tree);
+ }
+}
+
+/**
+ * g_tree_destroy:
+ * @tree: a #GTree.
+ *
+ * Removes all keys and values from the #GTree and decreases its
+ * reference count by one. If keys and/or values are dynamically
+ * allocated, you should either free them first or create the #GTree
+ * using g_tree_new_full(). In the latter case the destroy functions
+ * you supplied will be called on all keys and values before destroying
+ * the #GTree.
+ **/
+void
+g_tree_destroy (GTree *tree)
+{
+ g_return_if_fail (tree != NULL);
+
+ g_tree_remove_all (tree);
+ g_tree_unref (tree);
+}
+
+/**
+ * g_tree_insert:
+ * @tree: a #GTree.
+ * @key: the key to insert.
+ * @value: the value corresponding to the key.
+ *
+ * Inserts a key/value pair into a #GTree. If the given key already exists
+ * in the #GTree its corresponding value is set to the new value. If you
+ * supplied a value_destroy_func when creating the #GTree, the old value is
+ * freed using that function. If you supplied a @key_destroy_func when
+ * creating the #GTree, the passed key is freed using that function.
+ *
+ * The tree is automatically 'balanced' as new key/value pairs are added,
+ * so that the distance from the root to every leaf is as small as possible.
+ **/
+void
+g_tree_insert (GTree *tree,
+ gpointer key,
+ gpointer value)
+{
+ g_return_if_fail (tree != NULL);
+
+ g_tree_insert_internal (tree, key, value, FALSE);
+
+#ifdef G_TREE_DEBUG
+ g_tree_node_check (tree->root);
+#endif
+}
+
+/**
+ * g_tree_replace:
+ * @tree: a #GTree.
+ * @key: the key to insert.
+ * @value: the value corresponding to the key.
+ *
+ * Inserts a new key and value into a #GTree similar to g_tree_insert().
+ * The difference is that if the key already exists in the #GTree, it gets
+ * replaced by the new key. If you supplied a @value_destroy_func when
+ * creating the #GTree, the old value is freed using that function. If you
+ * supplied a @key_destroy_func when creating the #GTree, the old key is
+ * freed using that function.
+ *
+ * The tree is automatically 'balanced' as new key/value pairs are added,
+ * so that the distance from the root to every leaf is as small as possible.
+ **/
+void
+g_tree_replace (GTree *tree,
+ gpointer key,
+ gpointer value)
+{
+ g_return_if_fail (tree != NULL);
+
+ g_tree_insert_internal (tree, key, value, TRUE);
+
+#ifdef G_TREE_DEBUG
+ g_tree_node_check (tree->root);
+#endif
+}
+
+/* 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;
+ }
+}
+
+/**
+ * g_tree_remove:
+ * @tree: a #GTree.
+ * @key: the key to remove.
+ *
+ * Removes a key/value pair from a #GTree.
+ *
+ * If the #GTree was created using g_tree_new_full(), the key and value
+ * are freed using the supplied destroy functions, otherwise you have to
+ * make sure that any dynamically allocated values are freed yourself.
+ * If the key does not exist in the #GTree, the function does nothing.
+ *
+ * Returns: %TRUE if the key was found (prior to 2.8, this function returned
+ * nothing)
+ **/
+gboolean
+g_tree_remove (GTree *tree,
+ gconstpointer key)
+{
+ gboolean removed;
+
+ g_return_val_if_fail (tree != NULL, FALSE);
+
+ removed = g_tree_remove_internal (tree, key, FALSE);
+
+#ifdef G_TREE_DEBUG
+ g_tree_node_check (tree->root);
+#endif
+
+ return removed;
+}
+
+/**
+ * g_tree_steal:
+ * @tree: a #GTree.
+ * @key: the key to remove.
+ *
+ * Removes a key and its associated value from a #GTree without calling
+ * the key and value destroy functions.
+ *
+ * If the key does not exist in the #GTree, the function does nothing.
+ *
+ * Returns: %TRUE if the key was found (prior to 2.8, this function returned
+ * nothing)
+ **/
+gboolean
+g_tree_steal (GTree *tree,
+ gconstpointer key)
+{
+ gboolean removed;
+
+ g_return_val_if_fail (tree != NULL, FALSE);
+
+ removed = g_tree_remove_internal (tree, key, TRUE);
+
+#ifdef G_TREE_DEBUG
+ g_tree_node_check (tree->root);
+#endif
+
+ return removed;
+}
+
+/* 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;
+}
+
+/**
+ * g_tree_lookup:
+ * @tree: a #GTree.
+ * @key: the key to look up.
+ *
+ * Gets the value corresponding to the given key. Since a #GTree is
+ * automatically balanced as key/value pairs are added, key lookup is very
+ * fast.
+ *
+ * Return value: the value corresponding to the key, or %NULL if the key was
+ * not found.
+ **/
+gpointer
+g_tree_lookup (GTree *tree,
+ gconstpointer key)
+{
+ GTreeNode *node;
+
+ g_return_val_if_fail (tree != NULL, NULL);
+
+ node = g_tree_find_node (tree, key);
+
+ return node ? node->value : NULL;
+}
+
+/**
+ * g_tree_lookup_extended:
+ * @tree: a #GTree.
+ * @lookup_key: the key to look up.
+ * @orig_key: returns the original key.
+ * @value: returns the value associated with the key.
+ *
+ * Looks up a key in the #GTree, returning the original key and the
+ * associated value and a #gboolean which is %TRUE if the key was found. This
+ * is useful if you need to free the memory allocated for the original key,
+ * for example before calling g_tree_remove().
+ *
+ * Return value: %TRUE if the key was found in the #GTree.
+ **/
+gboolean
+g_tree_lookup_extended (GTree *tree,
+ gconstpointer lookup_key,
+ gpointer *orig_key,
+ gpointer *value)
+{
+ GTreeNode *node;
+
+ g_return_val_if_fail (tree != NULL, FALSE);
+
+ node = g_tree_find_node (tree, lookup_key);
+
+ if (node)
+ {
+ if (orig_key)
+ *orig_key = node->key;
+ if (value)
+ *value = node->value;
+ return TRUE;
+ }
+ else
+ return FALSE;
+}
+
+/**
+ * g_tree_foreach:
+ * @tree: a #GTree.
+ * @func: the function to call for each node visited. If this function
+ * returns %TRUE, the traversal is stopped.
+ * @user_data: user data to pass to the function.
+ *
+ * Calls the given function for each of the key/value pairs in the #GTree.
+ * The function is passed the key and value of each pair, and the given
+ * @data parameter. The tree is traversed in sorted order.
+ *
+ * The tree may not be modified while iterating over it (you can't
+ * add/remove items). To remove all items matching a predicate, you need
+ * to add each item to a list in your #GTraverseFunc as you walk over
+ * the tree, then walk the list and remove each item.
+ **/
+void
+g_tree_foreach (GTree *tree,
+ GTraverseFunc func,
+ gpointer user_data)
+{
+ GTreeNode *node;
+
+ g_return_if_fail (tree != NULL);
+
+ if (!tree->root)
+ return;
+
+ node = g_tree_first_node (tree);
+
+ while (node)
+ {
+ if ((*func) (node->key, node->value, user_data))
+ break;
+
+ node = g_tree_node_next (node);
+ }
+}
+
+/**
+ * g_tree_traverse:
+ * @tree: a #GTree.
+ * @traverse_func: the function to call for each node visited. If this
+ * function returns %TRUE, the traversal is stopped.
+ * @traverse_type: the order in which nodes are visited, one of %G_IN_ORDER,
+ * %G_PRE_ORDER and %G_POST_ORDER.
+ * @user_data: user data to pass to the function.
+ *
+ * Calls the given function for each node in the #GTree.
+ *
+ * Deprecated:2.2: The order of a balanced tree is somewhat arbitrary. If you
+ * just want to visit all nodes in sorted order, use g_tree_foreach()
+ * instead. If you really need to visit nodes in a different order, consider
+ * using an <link linkend="glib-N-ary-Trees">N-ary Tree</link>.
+ **/
+/**
+ * GTraverseFunc:
+ * @key: a key of a #GTree node.
+ * @value: the value corresponding to the key.
+ * @data: user data passed to g_tree_traverse().
+ * @Returns: %TRUE to stop the traversal.
+ *
+ * Specifies the type of function passed to g_tree_traverse(). It is
+ * passed the key and value of each node, together with the @user_data
+ * parameter passed to g_tree_traverse(). If the function returns
+ * %TRUE, the traversal is stopped.
+ **/
+/**
+ * GTraverseType:
+ * @G_IN_ORDER: vists a node's left child first, then the node itself,
+ * then its right child. This is the one to use if you
+ * want the output sorted according to the compare
+ * function.
+ * @G_PRE_ORDER: visits a node, then its children.
+ * @G_POST_ORDER: visits the node's children, then the node itself.
+ * @G_LEVEL_ORDER: is not implemented for <link
+ * linkend="glib-Balanced-Binary-Trees">Balanced Binary
+ * Trees</link>. For <link
+ * linkend="glib-N-ary-Trees">N-ary Trees</link>, it
+ * vists the root node first, then its children, then
+ * its grandchildren, and so on. Note that this is less
+ * efficient than the other orders.
+ *
+ * Specifies the type of traveral performed by g_tree_traverse(),
+ * g_node_traverse() and g_node_find().
+ **/
+void
+g_tree_traverse (GTree *tree,
+ GTraverseFunc traverse_func,
+ GTraverseType traverse_type,
+ gpointer user_data)
+{
+ g_return_if_fail (tree != NULL);
+
+ if (!tree->root)
+ return;
+
+ switch (traverse_type)
+ {
+ case G_PRE_ORDER:
+ g_tree_node_pre_order (tree->root, traverse_func, user_data);
+ break;
+
+ case G_IN_ORDER:
+ g_tree_node_in_order (tree->root, traverse_func, user_data);
+ break;
+
+ case G_POST_ORDER:
+ g_tree_node_post_order (tree->root, traverse_func, user_data);
+ break;
+
+ case G_LEVEL_ORDER:
+ g_warning ("g_tree_traverse(): traverse type G_LEVEL_ORDER isn't implemented.");
+ break;
+ }
+}
+
+/**
+ * g_tree_search:
+ * @tree: a #GTree
+ * @search_func: a function used to search the #GTree
+ * @user_data: the data passed as the second argument to @search_func
+ *
+ * Searches a #GTree using @search_func.
+ *
+ * The @search_func is called with a pointer to the key of a key/value
+ * pair in the tree, and the passed in @user_data. If @search_func returns
+ * 0 for a key/value pair, then the corresponding value is returned as
+ * the result of g_tree_search(). If @search_func returns -1, searching
+ * will proceed among the key/value pairs that have a smaller key; if
+ * @search_func returns 1, searching will proceed among the key/value
+ * pairs that have a larger key.
+ *
+ * Return value: the value corresponding to the found key, or %NULL if
+ * the key was not found.
+ */
+gpointer
+g_tree_search (GTree *tree,
+ GCompareFunc search_func,
+ gconstpointer user_data)
+{
+ g_return_val_if_fail (tree != NULL, NULL);
+
+ if (tree->root)
+ return g_tree_node_search (tree->root, search_func, user_data);
+ else
+ return NULL;
+}
+
+/**
+ * g_tree_height:
+ * @tree: a #GTree.
+ *
+ * Gets the height of a #GTree.
+ *
+ * If the #GTree contains no nodes, the height is 0.
+ * If the #GTree contains only one root node the height is 1.
+ * If the root node has children the height is 2, etc.
+ *
+ * Return value: the height of the #GTree.
+ **/
+gint
+g_tree_height (GTree *tree)
+{
+ GTreeNode *node;
+ gint height;
+
+ g_return_val_if_fail (tree != NULL, 0);
+
+ if (!tree->root)
+ return 0;
+
+ height = 0;
+ node = tree->root;
+
+ while (1)
+ {
+ height += 1 + MAX(node->balance, 0);
+
+ if (!node->left_child)
+ return height;
+
+ node = node->left;
+ }
+}
+
+/**
+ * g_tree_nnodes:
+ * @tree: a #GTree.
+ *
+ * Gets the number of nodes in a #GTree.
+ *
+ * Return value: the number of nodes in the #GTree.
+ **/
+gint
+g_tree_nnodes (GTree *tree)
+{
+ g_return_val_if_fail (tree != NULL, 0);
+
+ return tree->nnodes;
+}
+
+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_find_node (GTree *tree,
+ gconstpointer key)
+{
+ GTreeNode *node;
+ gint cmp;
+
+ node = tree->root;
+ if (!node)
+ return NULL;
+
+ while (1)
+ {
+ cmp = tree->key_compare (key, node->key, tree->key_compare_data);
+ if (cmp == 0)
+ return node;
+ else if (cmp < 0)
+ {
+ if (!node->left_child)
+ return NULL;
+
+ node = node->left;
+ }
+ else
+ {
+ if (!node->right_child)
+ return NULL;
+
+ node = node->right;
+ }
+ }
+}
+
+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_child)
+ {
+ if (g_tree_node_pre_order (node->left, traverse_func, data))
+ return TRUE;
+ }
+
+ if (node->right_child)
+ {
+ 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_child)
+ {
+ 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_child)
+ {
+ 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_child)
+ {
+ if (g_tree_node_post_order (node->left, traverse_func, data))
+ return TRUE;
+ }
+
+ if (node->right_child)
+ {
+ 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,
+ GCompareFunc search_func,
+ gconstpointer data)
+{
+ gint dir;
+
+ if (!node)
+ return NULL;
+
+ while (1)
+ {
+ dir = (* search_func) (node->key, data);
+ if (dir == 0)
+ return node->value;
+ else if (dir < 0)
+ {
+ if (!node->left_child)
+ return NULL;
+
+ node = node->left;
+ }
+ else
+ {
+ if (!node->right_child)
+ return NULL;
+
+ node = node->right;
+ }
+ }
+}
+
+static GTreeNode*
+g_tree_node_rotate_left (GTreeNode *node)
+{
+ GTreeNode *right;
+ gint a_bal;
+ gint b_bal;
+
+ right = node->right;
+
+ if (right->left_child)
+ node->right = right->left;
+ else
+ {
+ node->right_child = FALSE;
+ right->left_child = TRUE;
+ }
+ 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;
+ gint a_bal;
+ gint b_bal;
+
+ left = node->left;
+
+ if (left->right_child)
+ node->left = left->right;
+ else
+ {
+ node->left_child = FALSE;
+ left->right_child = TRUE;
+ }
+ 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;
+}
+
+#ifdef G_TREE_DEBUG
+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_child)
+ left_height = g_tree_node_height (node->left);
+
+ if (node->right_child)
+ right_height = g_tree_node_height (node->right);
+
+ return MAX (left_height, right_height) + 1;
+ }
+
+ return 0;
+}
+
+static void
+g_tree_node_check (GTreeNode *node)
+{
+ gint left_height;
+ gint right_height;
+ gint balance;
+ GTreeNode *tmp;
+
+ if (node)
+ {
+ if (node->left_child)
+ {
+ tmp = g_tree_node_previous (node);
+ g_assert (tmp->right == node);
+ }
+
+ if (node->right_child)
+ {
+ tmp = g_tree_node_next (node);
+ g_assert (tmp->left == node);
+ }
+
+ left_height = 0;
+ right_height = 0;
+
+ if (node->left_child)
+ left_height = g_tree_node_height (node->left);
+ if (node->right_child)
+ right_height = g_tree_node_height (node->right);
+
+ balance = right_height - left_height;
+ g_assert (balance == node->balance);
+
+ if (node->left_child)
+ g_tree_node_check (node->left);
+ if (node->right_child)
+ g_tree_node_check (node->right);
+ }
+}
+
+static void
+g_tree_node_dump (GTreeNode *node,
+ gint indent)
+{
+ g_print ("%*s%c\n", indent, "", *(char *)node->key);
+
+ if (node->left_child)
+ g_tree_node_dump (node->left, indent + 2);
+ else if (node->left)
+ g_print ("%*s<%c\n", indent + 2, "", *(char *)node->left->key);
+
+ if (node->right_child)
+ g_tree_node_dump (node->right, indent + 2);
+ else if (node->right)
+ g_print ("%*s>%c\n", indent + 2, "", *(char *)node->right->key);
+}
+
+
+void
+g_tree_dump (GTree *tree)
+{
+ if (tree->root)
+ g_tree_node_dump (tree->root, 0);
+}
+#endif
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