GTree

typedef struct _GTree GTree;

The GTree struct is an opaque data structure representing a Balanced Binary Tree. It should be accessed only by using the following functions.

g_tree_new ()

GTree*      g_tree_new                      (GCompareFunc key_compare_func);

Creates a new GTree.

g_tree_new_with_data ()

GTree*      g_tree_new_with_data            (GCompareDataFunc key_compare_func,
                                             gpointer key_compare_data);

Creates a new GTree with a comparison function that accepts user data. See g_tree_new() for more details.

g_tree_new_full ()

GTree*      g_tree_new_full                 (GCompareDataFunc key_compare_func,
                                             gpointer key_compare_data,
                                             GDestroyNotify key_destroy_func,
                                             GDestroyNotify value_destroy_func);

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.

g_tree_insert ()

void        g_tree_insert                   (GTree *tree,
                                             gpointer key,
                                             gpointer value);

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.

g_tree_replace ()

void        g_tree_replace                  (GTree *tree,
                                             gpointer key,
                                             gpointer value);

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.

g_tree_nnodes ()

gint        g_tree_nnodes                   (GTree *tree);

Gets the number of nodes in a GTree.

g_tree_height ()

gint        g_tree_height                   (GTree *tree);

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.

g_tree_lookup ()

gpointer    g_tree_lookup                   (GTree *tree,
                                             gconstpointer key);

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.

g_tree_lookup_extended ()

gboolean    g_tree_lookup_extended          (GTree *tree,
                                             gconstpointer lookup_key,
                                             gpointer *orig_key,
                                             gpointer *value);

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().

g_tree_foreach ()

void        g_tree_foreach                  (GTree *tree,
                                             GTraverseFunc func,
                                             gpointer user_data);

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.

g_tree_traverse ()

void        g_tree_traverse                 (GTree *tree,
                                             GTraverseFunc traverse_func,
                                             GTraverseType traverse_type,
                                             gpointer user_data);

Calls the given function for each node in the GTree.

GTraverseFunc ()

gboolean    (*GTraverseFunc)                (gpointer key,
                                             gpointer value,
                                             gpointer data);

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.

enum GTraverseType

typedef enum
{
  G_IN_ORDER,
  G_PRE_ORDER,
  G_POST_ORDER,
  G_LEVEL_ORDER
} GTraverseType;

Specifies the type of traveral performed by g_tree_traverse(), g_node_traverse() and g_node_find().

g_tree_search ()

gpointer    g_tree_search                   (GTree *tree,
                                             GCompareFunc search_func,
                                             gconstpointer user_data);

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 g_tree_search_func() will return the value of that pair. 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.

g_tree_remove ()

void        g_tree_remove                   (GTree *tree,
                                             gconstpointer key);

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.

g_tree_steal ()

void        g_tree_steal                    (GTree *tree,
                                             gconstpointer key);

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.

g_tree_destroy ()

void        g_tree_destroy                  (GTree *tree);

Destroys the GTree. 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.