* 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
+ * 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
- * Library General Public License for more details.
+ * Lesser 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., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
-#include "glib.h"
+/*
+ * 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 _GRealTree GRealTree;
typedef struct _GTreeNode GTreeNode;
-struct _GRealTree
+/**
+ * GTree:
+ *
+ * The GTree struct is an opaque data structure representing a
+ * [balanced binary tree][glib-Balanced-Binary-Trees]. It should be
+ * accessed only by using the following functions.
+ */
+struct _GTree
{
- GTreeNode *root;
- GCompareFunc key_compare;
+ GTreeNode *root;
+ GCompareDataFunc key_compare;
+ GDestroyNotify key_destroy_func;
+ GDestroyNotify value_destroy_func;
+ gpointer key_compare_data;
+ guint nnodes;
+ gint ref_count;
};
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 */
+ 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_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 GTreeNode *node_free_list = NULL;
+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)
+ gpointer value)
{
- GTreeNode *node;
-
- if (node_free_list)
- {
- node = node_free_list;
- node_free_list = node->right;
- }
- else
- {
- if (!node_mem_chunk)
- node_mem_chunk = g_mem_chunk_new ("GLib GTreeNode mem chunk",
- sizeof (GTreeNode),
- 1024,
- G_ALLOC_ONLY);
-
- node = g_chunk_new (GTreeNode, node_mem_chunk);
- }
+ 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;
}
-static void
-g_tree_node_destroy (GTreeNode *node)
-{
- if (node)
- {
- g_tree_node_destroy (node->right);
- g_tree_node_destroy (node->left);
- node->right = node_free_list;
- node_free_list = node;
- }
-}
-
-
-GTree*
+/**
+ * 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.
+ *
+ * Returns: a newly allocated #GTree
+ */
+GTree *
g_tree_new (GCompareFunc key_compare_func)
{
- GRealTree *rtree;
-
g_return_val_if_fail (key_compare_func != NULL, NULL);
- rtree = g_new (GRealTree, 1);
- rtree->root = NULL;
- rtree->key_compare = key_compare_func;
-
- return (GTree*) rtree;
+ return g_tree_new_full ((GCompareDataFunc) key_compare_func, NULL,
+ NULL, NULL);
}
-void
-g_tree_destroy (GTree *tree)
+/**
+ * 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.
+ *
+ * Returns: a newly allocated #GTree
+ */
+GTree *
+g_tree_new_with_data (GCompareDataFunc key_compare_func,
+ gpointer key_compare_data)
{
- GRealTree *rtree;
-
- g_return_if_fail (tree != NULL);
-
- rtree = (GRealTree*) tree;
+ 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_node_destroy (rtree->root);
- g_free (rtree);
+/**
+ * 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.
+ *
+ * Returns: a newly allocated #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;
}
-void
-g_tree_insert (GTree *tree,
- gpointer key,
- gpointer value)
+static inline GTreeNode *
+g_tree_first_node (GTree *tree)
{
- GRealTree *rtree;
- gint inserted;
+ GTreeNode *tmp;
- g_return_if_fail (tree != NULL);
+ if (!tree->root)
+ return NULL;
- rtree = (GRealTree*) tree;
+ tmp = tree->root;
- inserted = FALSE;
- rtree->root = g_tree_node_insert (rtree->root, rtree->key_compare,
- key, value, &inserted);
-}
+ while (tmp->left_child)
+ tmp = tmp->left;
-void
-g_tree_remove (GTree *tree,
- gpointer key)
+ return tmp;
+}
+
+static inline GTreeNode *
+g_tree_node_previous (GTreeNode *node)
{
- GRealTree *rtree;
+ GTreeNode *tmp;
- g_return_if_fail (tree != NULL);
+ tmp = node->left;
- rtree = (GRealTree*) tree;
+ if (node->left_child)
+ while (tmp->right_child)
+ tmp = tmp->right;
- rtree->root = g_tree_node_remove (rtree->root, rtree->key_compare, key);
+ return tmp;
}
-gpointer
-g_tree_lookup (GTree *tree,
- gpointer key)
+static inline GTreeNode *
+g_tree_node_next (GTreeNode *node)
{
- GRealTree *rtree;
+ GTreeNode *tmp;
- g_return_val_if_fail (tree != NULL, NULL);
+ tmp = node->right;
- rtree = (GRealTree*) tree;
+ if (node->right_child)
+ while (tmp->left_child)
+ tmp = tmp->left;
- return g_tree_node_lookup (rtree->root, rtree->key_compare, key);
+ return tmp;
}
-void
-g_tree_traverse (GTree *tree,
- GTraverseFunc traverse_func,
- GTraverseType traverse_type,
- gpointer data)
+static void
+g_tree_remove_all (GTree *tree)
{
- GRealTree *rtree;
+ GTreeNode *node;
+ GTreeNode *next;
g_return_if_fail (tree != NULL);
- rtree = (GRealTree*) tree;
+ node = g_tree_first_node (tree);
- g_return_if_fail (rtree->root != NULL);
-
- switch (traverse_type)
+ while (node)
{
- case G_PRE_ORDER:
- g_tree_node_pre_order (rtree->root, traverse_func, data);
- break;
+ next = g_tree_node_next (node);
- case G_IN_ORDER:
- g_tree_node_in_order (rtree->root, traverse_func, data);
- break;
+ 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);
- case G_POST_ORDER:
- g_tree_node_post_order (rtree->root, traverse_func, data);
- break;
-
- case G_LEVEL_ORDER:
- g_warning ("g_tree_traverse(): traverse type G_LEVEL_ORDER isn't implemented.");
- break;
+ node = next;
}
+
+ tree->root = NULL;
+ tree->nnodes = 0;
}
-gpointer
-g_tree_search (GTree *tree,
- GSearchFunc search_func,
- gpointer data)
+/**
+ * g_tree_ref:
+ * @tree: a #GTree
+ *
+ * Increments the reference count of @tree by one.
+ *
+ * It is safe to call this function from any thread.
+ *
+ * Returns: the passed in #GTree
+ *
+ * Since: 2.22
+ */
+GTree *
+g_tree_ref (GTree *tree)
{
- GRealTree *rtree;
-
g_return_val_if_fail (tree != NULL, NULL);
- rtree = (GRealTree*) tree;
+ g_atomic_int_inc (&tree->ref_count);
- if (rtree->root)
- return g_tree_node_search (rtree->root, search_func, data);
- return NULL;
+ return tree;
}
-gint
-g_tree_height (GTree *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)
{
- GRealTree *rtree;
+ g_return_if_fail (tree != NULL);
- g_return_val_if_fail (tree != NULL, 0);
+ if (g_atomic_int_dec_and_test (&tree->ref_count))
+ {
+ g_tree_remove_all (tree);
+ g_slice_free (GTree, tree);
+ }
+}
- rtree = (GRealTree*) 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);
- if (rtree->root)
- return g_tree_node_height (rtree->root);
- return 0;
+ g_tree_remove_all (tree);
+ g_tree_unref (tree);
}
-gint
-g_tree_nnodes (GTree *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)
{
- GRealTree *rtree;
+ g_return_if_fail (tree != NULL);
- g_return_val_if_fail (tree != NULL, 0);
+ 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);
- rtree = (GRealTree*) tree;
+ g_tree_insert_internal (tree, key, value, TRUE);
- if (rtree->root)
- return g_tree_node_count (rtree->root);
- return 0;
+#ifdef G_TREE_DEBUG
+ g_tree_node_check (tree->root);
+#endif
}
-static GTreeNode*
-g_tree_node_insert (GTreeNode *node,
- GCompareFunc compare,
- gpointer key,
- gpointer value,
- gint *inserted)
+/* internal insert routine */
+static void
+g_tree_insert_internal (GTree *tree,
+ gpointer key,
+ gpointer value,
+ gboolean replace)
{
- gint old_balance;
- gint cmp;
+ GTreeNode *node;
+ GTreeNode *path[MAX_GTREE_HEIGHT];
+ int idx;
- if (!node)
- {
- *inserted = TRUE;
- return g_tree_node_new (key, value);
- }
+ g_return_if_fail (tree != NULL);
- cmp = (* compare) (key, node->key);
- if (cmp == 0)
+ if (!tree->root)
{
- *inserted = FALSE;
- node->value = value;
- return node;
+ tree->root = g_tree_node_new (key, value);
+ tree->nnodes++;
+ return;
}
- if (cmp < 0)
+ idx = 0;
+ path[idx++] = NULL;
+ node = tree->root;
+
+ while (1)
{
- 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;
- }
+ 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
- {
- *inserted = TRUE;
- node->left = g_tree_node_new (key, value);
- node->balance -= 1;
- }
+ {
+ 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;
+ }
+ }
}
- else if (cmp > 0)
+
+ /* 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)
{
- 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;
- }
+ 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
- {
- *inserted = TRUE;
- node->right = g_tree_node_new (key, value);
- node->balance += 1;
- }
- }
+ bparent->balance += 1;
- if (*inserted)
- {
- if ((node->balance < -1) || (node->balance > 1))
- node = g_tree_node_balance (node);
+ node = bparent;
}
+}
- return node;
+/**
+ * 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;
}
-static GTreeNode*
-g_tree_node_remove (GTreeNode *node,
- GCompareFunc compare,
- gpointer key)
+/**
+ * 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)
{
- GTreeNode *new_root;
- gint old_balance;
- gint cmp;
+ gboolean removed;
- if (!node)
- return NULL;
+ g_return_val_if_fail (tree != NULL, FALSE);
- cmp = (* compare) (key, node->key);
- if (cmp == 0)
- {
- GTreeNode *garbage;
+ 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);
- garbage = node;
+ if (!tree->root)
+ return FALSE;
- if (!node->right)
- {
- node = node->left;
- }
+ 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
- {
- 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);
- }
-
- garbage->right = node_free_list;
- node_free_list = garbage;
+ {
+ if (!node->right_child)
+ return FALSE;
+
+ path[idx++] = node;
+ node = node->right;
+ }
}
- else if (cmp < 0)
+
+ /* 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->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);
- }
+ 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 if (cmp > 0)
+ else /* node has a left child */
{
- 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);
- }
+ 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;
+ }
}
- return node;
+ /* 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;
}
-static GTreeNode*
-g_tree_node_balance (GTreeNode *node)
+/**
+ * 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 O(log n) (where n is the number of key/value pairs in the tree).
+ *
+ * Returns: the value corresponding to the key, or %NULL
+ * if the key was not found
+ */
+gpointer
+g_tree_lookup (GTree *tree,
+ gconstpointer key)
{
- if (node->balance < -1)
+ 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. This is useful if you need to free the memory
+ * allocated for the original key, for example before calling
+ * g_tree_remove().
+ *
+ * Returns: %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 (node->left->balance > 0)
- node->left = g_tree_node_rotate_left (node->left);
- node = g_tree_node_rotate_right (node);
+ if (orig_key)
+ *orig_key = node->key;
+ if (value)
+ *value = node->value;
+ return TRUE;
}
- else if (node->balance > 1)
+ 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 (node->right->balance < 0)
- node->right = g_tree_node_rotate_right (node->right);
- node = g_tree_node_rotate_left (node);
+ if ((*func) (node->key, node->value, user_data))
+ break;
+
+ node = g_tree_node_next (node);
}
-
- return node;
}
-static GTreeNode*
-g_tree_node_remove_leftmost (GTreeNode *node,
- GTreeNode **leftmost)
+/**
+ * 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 [n-ary tree][glib-N-ary-Trees].
+ */
+/**
+ * GTraverseFunc:
+ * @key: a key of a #GTree node
+ * @value: the value corresponding to the key
+ * @data: user data passed to g_tree_traverse()
+ *
+ * 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.
+ *
+ * Returns: %TRUE to stop the traversal
+ */
+void
+g_tree_traverse (GTree *tree,
+ GTraverseFunc traverse_func,
+ GTraverseType traverse_type,
+ gpointer user_data)
{
- gint old_balance;
+ g_return_if_fail (tree != NULL);
+
+ if (!tree->root)
+ return;
- if (!node->left)
+ switch (traverse_type)
{
- *leftmost = node;
- return node->right;
- }
+ 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;
- 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);
+ 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;
+ }
}
-static GTreeNode*
-g_tree_node_restore_left_balance (GTreeNode *node,
- gint old_balance)
+/**
+ * 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.
+ *
+ * Returns: 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)
{
- if (!node->left)
- node->balance += 1;
- else if ((node->left->balance != old_balance) &&
- (node->left->balance == 0))
- node->balance += 1;
+ g_return_val_if_fail (tree != NULL, NULL);
- if (node->balance > 1)
- return g_tree_node_balance (node);
- return node;
+ if (tree->root)
+ return g_tree_node_search (tree->root, search_func, user_data);
+ else
+ return NULL;
}
-static GTreeNode*
-g_tree_node_restore_right_balance (GTreeNode *node,
- gint old_balance)
+/**
+ * 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.
+ *
+ * Returns: the height of @tree
+ */
+gint
+g_tree_height (GTree *tree)
{
- if (!node->right)
- node->balance -= 1;
- else if ((node->right->balance != old_balance) &&
- (node->right->balance == 0))
- node->balance -= 1;
+ GTreeNode *node;
+ gint height;
- if (node->balance < -1)
- return g_tree_node_balance (node);
- return node;
+ 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;
+ }
}
-static gpointer
-g_tree_node_lookup (GTreeNode *node,
- GCompareFunc compare,
- gpointer key)
+/**
+ * g_tree_nnodes:
+ * @tree: a #GTree
+ *
+ * Gets the number of nodes in a #GTree.
+ *
+ * Returns: the number of nodes in @tree
+ */
+gint
+g_tree_nnodes (GTree *tree)
{
- gint cmp;
-
- if (!node)
- return NULL;
+ g_return_val_if_fail (tree != NULL, 0);
- cmp = (* compare) (key, node->key);
- if (cmp == 0)
- return node->value;
+ return tree->nnodes;
+}
- if (cmp < 0)
+static GTreeNode *
+g_tree_node_balance (GTreeNode *node)
+{
+ if (node->balance < -1)
{
- if (node->left)
- return g_tree_node_lookup (node->left, compare, key);
+ if (node->left->balance > 0)
+ node->left = g_tree_node_rotate_left (node->left);
+ node = g_tree_node_rotate_right (node);
}
- else if (cmp > 0)
+ else if (node->balance > 1)
{
- if (node->right)
- return g_tree_node_lookup (node->right, compare, key);
+ if (node->right->balance < 0)
+ node->right = g_tree_node_rotate_right (node->right);
+ node = g_tree_node_rotate_left (node);
}
- return NULL;
+ return node;
}
-static gint
-g_tree_node_count (GTreeNode *node)
+static GTreeNode *
+g_tree_find_node (GTree *tree,
+ gconstpointer key)
{
- gint count;
+ GTreeNode *node;
+ gint cmp;
- count = 1;
- if (node->left)
- count += g_tree_node_count (node->left);
- if (node->right)
- count += g_tree_node_count (node->right);
+ 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;
- return count;
+ node = node->right;
+ }
+ }
}
static gint
g_tree_node_pre_order (GTreeNode *node,
- GTraverseFunc traverse_func,
- gpointer data)
+ GTraverseFunc traverse_func,
+ gpointer data)
{
if ((*traverse_func) (node->key, node->value, data))
return TRUE;
- if (node->left)
+
+ if (node->left_child)
{
if (g_tree_node_pre_order (node->left, traverse_func, data))
- return TRUE;
+ return TRUE;
}
- if (node->right)
+
+ if (node->right_child)
{
if (g_tree_node_pre_order (node->right, traverse_func, data))
- return TRUE;
+ return TRUE;
}
return FALSE;
static gint
g_tree_node_in_order (GTreeNode *node,
- GTraverseFunc traverse_func,
- gpointer data)
+ GTraverseFunc traverse_func,
+ gpointer data)
{
- if (node->left)
+ if (node->left_child)
{
if (g_tree_node_in_order (node->left, traverse_func, data))
- return TRUE;
+ return TRUE;
}
+
if ((*traverse_func) (node->key, node->value, data))
return TRUE;
- if (node->right)
+
+ if (node->right_child)
{
if (g_tree_node_in_order (node->right, traverse_func, data))
- return TRUE;
+ return TRUE;
}
-
+
return FALSE;
}
static gint
g_tree_node_post_order (GTreeNode *node,
- GTraverseFunc traverse_func,
- gpointer data)
+ GTraverseFunc traverse_func,
+ gpointer data)
{
- if (node->left)
+ if (node->left_child)
{
if (g_tree_node_post_order (node->left, traverse_func, data))
- return TRUE;
+ return TRUE;
}
- if (node->right)
+
+ if (node->right_child)
{
if (g_tree_node_post_order (node->right, traverse_func, data))
- return TRUE;
+ return TRUE;
}
+
if ((*traverse_func) (node->key, node->value, data))
return TRUE;
}
static gpointer
-g_tree_node_search (GTreeNode *node,
- GSearchFunc search_func,
- gpointer data)
+g_tree_node_search (GTreeNode *node,
+ GCompareFunc search_func,
+ gconstpointer 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)
+ while (1)
{
- 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);
+ 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;
- return MAX (left_height, right_height) + 1;
+ node = node->right;
+ }
}
-
- return 0;
}
-static GTreeNode*
+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;
+ if (right->left_child)
+ node->right = right->left;
+ else
+ {
+ node->right_child = FALSE;
+ right->left_child = TRUE;
+ }
right->left = node;
a_bal = node->balance;
if (b_bal <= 0)
{
if (a_bal >= 1)
- right->balance = b_bal - 1;
+ right->balance = b_bal - 1;
else
- right->balance = a_bal + b_bal - 2;
+ right->balance = a_bal + b_bal - 2;
node->balance = a_bal - 1;
}
else
{
if (a_bal <= b_bal)
- right->balance = a_bal - 2;
+ right->balance = a_bal - 2;
else
- right->balance = b_bal - 1;
+ right->balance = b_bal - 1;
node->balance = a_bal - b_bal - 1;
}
return right;
}
-static GTreeNode*
+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;
+ if (left->right_child)
+ node->left = left->right;
+ else
+ {
+ node->left_child = FALSE;
+ left->right_child = TRUE;
+ }
left->right = node;
a_bal = node->balance;
if (b_bal <= 0)
{
if (b_bal > a_bal)
- left->balance = b_bal + 1;
+ left->balance = b_bal + 1;
else
- left->balance = a_bal + 2;
+ left->balance = a_bal + 2;
node->balance = a_bal - b_bal + 1;
}
else
{
if (a_bal <= -1)
- left->balance = b_bal + 1;
+ left->balance = b_bal + 1;
else
- left->balance = a_bal + b_bal + 2;
+ 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)
- left_height = g_tree_node_height (node->left);
- if (node->right)
- right_height = g_tree_node_height (node->right);
+ 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;
- if (balance != node->balance)
- g_log (g_log_domain_glib, G_LOG_LEVEL_INFO,
- "g_tree_node_check: failed: %d ( %d )\n",
- balance, node->balance);
+ g_assert (balance == node->balance);
- if (node->left)
- g_tree_node_check (node->left);
- if (node->right)
- g_tree_node_check (node->right);
+ 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