GLib.Tree¶

Fields¶

None

Methods¶

class	`new_full` (key_compare_func, key_compare_data, key_destroy_func)
	`destroy` ()
	`foreach` (func, *user_data)
	`foreach_node` (func, *user_data)
	`height` ()
	`insert` (key, value)
	`insert_node` (key, value)
	`lookup` (key)
	`lookup_extended` (lookup_key)
	`lookup_node` (key)
	`lower_bound` (key)
	`nnodes` ()
	`node_first` ()
	`node_last` ()
	`ref` ()
	`remove` (key)
	`remove_all` ()
	`replace` (key, value)
	`replace_node` (key, value)
	`search` (search_func, *user_data)
	`search_node` (search_func, *user_data)
	`steal` (key)
	`traverse` (traverse_func, traverse_type, *user_data)
	`unref` ()
	`upper_bound` (key)

Details¶

class GLib.Tree¶

The GLib.Tree struct is an opaque data structure representing a balanced binary tree. It should be accessed only by using the following functions.

classmethod new_full(key_compare_func, key_compare_data, key_destroy_func)[source]¶

Parameters:

key_compare_func (GLib.CompareDataFunc) – qsort()-style comparison function
key_compare_data (object or None) – data to pass to comparison function
key_destroy_func (GLib.DestroyNotify) – a function to free the memory allocated for the key used when removing the entry from the GLib.Tree or None if you don’t want to supply such a function

Returns:

a newly allocated GLib.Tree

Return type:

GLib.Tree

Creates a new GLib.Tree 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 GLib.Tree.

destroy()[source]¶: Removes all keys and values from the GLib.Tree and decreases its reference count by one. If keys and/or values are dynamically allocated, you should either free them first or create the GLib.Tree using GLib.Tree.new_full(). In the latter case the destroy functions you supplied will be called on all keys and values before destroying the GLib.Tree.

foreach(func, *user_data)[source]¶

Parameters:

func (GLib.TraverseFunc) – the function to call for each node visited. If this function returns True, the traversal is stopped.
user_data (object or None) – user data to pass to the function

Calls the given function for each of the key/value pairs in the GLib.Tree. 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 GLib.TraverseFunc as you walk over the tree, then walk the list and remove each item.

foreach_node(func, *user_data)[source]¶

Parameters:

func (GLib.TraverseNodeFunc) – the function to call for each node visited. If this function returns True, the traversal is stopped.
user_data (object or None) – user data to pass to the function

Calls the given function for each of the nodes in the GLib.Tree. The function is passed the pointer to the particular node, and the given data parameter. The tree traversal happens in-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 GLib.TraverseFunc as you walk over the tree, then walk the list and remove each item.

New in version 2.68.

height()[source]¶

Returns:: the height of self
Return type:: int

Gets the height of a GLib.Tree.

If the GLib.Tree contains no nodes, the height is 0. If the GLib.Tree contains only one root node the height is 1. If the root node has children the height is 2, etc.

insert(key, value)[source]¶

Parameters:

key (object or None) – the key to insert
value (object or None) – the value corresponding to the key

Inserts a key/value pair into a GLib.Tree.

Inserts a new key and value into a GLib.Tree as GLib.Tree.insert_node() does, only this function does not return the inserted or set node.

insert_node(key, value)[source]¶

Parameters:

key (object or None) – the key to insert
value (object or None) – the value corresponding to the key

Returns:

the inserted (or set) node or None if insertion would overflow the tree node counter.

Return type:

GLib.TreeNode or None

Inserts a key/value pair into a GLib.Tree.

If the given key already exists in the GLib.Tree its corresponding value is set to the new value. If you supplied a value_destroy_func when creating the GLib.Tree, the old value is freed using that function. If you supplied a key_destroy_func when creating the GLib.Tree, 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. The cost of maintaining a balanced tree while inserting new key/value result in a O(n log(n)) operation where most of the other operations are O(log(n)).

New in version 2.68.

lookup(key)[source]¶

Parameters:: key (object or None) – the key to look up
Returns:: the value corresponding to the key, or None if the key was not found
Return type:: object or None

Gets the value corresponding to the given key. Since a GLib.Tree 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).

lookup_extended(lookup_key)[source]¶

Parameters:

lookup_key (object or None) – the key to look up

Returns:

True if the key was found in the GLib.Tree

orig_key:: returns the original key
value:: returns the value associated with the key

Return type:

(bool, orig_key: object, value: object)

Looks up a key in the GLib.Tree, 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 GLib.Tree.remove().

lookup_node(key)[source]¶

Parameters:: key (object or None) – the key to look up
Returns:: the tree node corresponding to the key, or None if the key was not found
Return type:: GLib.TreeNode or None

Gets the tree node corresponding to the given key. Since a GLib.Tree 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).

New in version 2.68.

lower_bound(key)[source]¶

Parameters:: key (object or None) – the key to calculate the lower bound for
Returns:: the tree node corresponding to the lower bound, or None if the tree is empty or has only keys strictly lower than the searched key.
Return type:: GLib.TreeNode or None

Gets the lower bound node corresponding to the given key, or None if the tree is empty or all the nodes in the tree have keys that are strictly lower than the searched key.

The lower bound is the first node that has its key greater than or equal to the searched key.

New in version 2.68.

nnodes()[source]¶

Returns:

the number of nodes in self

The node counter value type is really a int, but it is returned as a int due to backward compatibility issues (can be cast back to int to support its full range of values).

Return type:

int

Gets the number of nodes in a GLib.Tree.

node_first()[source]¶

Returns:: the first node in the tree
Return type:: GLib.TreeNode or None

Returns the first in-order node of the tree, or None for an empty tree.

New in version 2.68.

node_last()[source]¶

Returns:: the last node in the tree
Return type:: GLib.TreeNode or None

Returns the last in-order node of the tree, or None for an empty tree.

New in version 2.68.

ref()[source]¶

Returns:: the passed in GLib.Tree
Return type:: GLib.Tree

Increments the reference count of self by one.

It is safe to call this function from any thread.

New in version 2.22.

remove(key)[source]¶

Parameters:: key (object or None) – the key to remove
Returns:: True if the key was found (prior to 2.8, this function returned nothing)
Return type:: bool

Removes a key/value pair from a GLib.Tree.

If the GLib.Tree was created using GLib.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 GLib.Tree, the function does nothing.

The cost of maintaining a balanced tree while removing a key/value result in a O(n log(n)) operation where most of the other operations are O(log(n)).

remove_all()[source]¶: Removes all nodes from a GLib.Tree and destroys their keys and values, then resets the GLib.Tree’s root to None.

New in version 2.70.

replace(key, value)[source]¶

Parameters:

key (object or None) – the key to insert
value (object or None) – the value corresponding to the key

Inserts a new key and value into a GLib.Tree as GLib.Tree.replace_node() does, only this function does not return the inserted or set node.

replace_node(key, value)[source]¶

Parameters:

key (object or None) – the key to insert
value (object or None) – the value corresponding to the key

Returns:

the inserted (or set) node or None if insertion would overflow the tree node counter.

Return type:

GLib.TreeNode or None

Inserts a new key and value into a GLib.Tree similar to GLib.Tree.insert_node(). The difference is that if the key already exists in the GLib.Tree, it gets replaced by the new key. If you supplied a value_destroy_func when creating the GLib.Tree, the old value is freed using that function. If you supplied a key_destroy_func when creating the GLib.Tree, 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.

New in version 2.68.

search(search_func, *user_data)[source]¶

Parameters:

search_func (GLib.CompareFunc) – a function used to search the GLib.Tree
user_data (object or None) – the data passed as the second argument to search_func

Returns:

the value corresponding to the found key, or None if the key was not found

Return type:

object or None

Searches a GLib.Tree 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 GLib.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.

search_node(search_func, *user_data)[source]¶

Parameters:

search_func (GLib.CompareFunc) – a function used to search the GLib.Tree
user_data (object or None) – the data passed as the second argument to search_func

Returns:

the node corresponding to the found key, or None if the key was not found

Return type:

GLib.TreeNode or None

Searches a GLib.Tree 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 node is returned as the result of GLib.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.

New in version 2.68.

steal(key)[source]¶

Parameters:: key (object or None) – the key to remove
Returns:: True if the key was found (prior to 2.8, this function returned nothing)
Return type:: bool

Removes a key and its associated value from a GLib.Tree without calling the key and value destroy functions.

If the key does not exist in the GLib.Tree, the function does nothing.

traverse(traverse_func, traverse_type, *user_data)[source]¶

Parameters:

traverse_func (GLib.TraverseFunc) – the function to call for each node visited. If this function returns True, the traversal is stopped.
traverse_type (GLib.TraverseType) – the order in which nodes are visited, one of GLib.TraverseType.IN_ORDER, GLib.TraverseType.PRE_ORDER and GLib.TraverseType.POST_ORDER
user_data (object or None) – user data to pass to the function

Calls the given function for each node in the GLib.Tree.

Deprecated since version 2.2: The order of a balanced tree is somewhat arbitrary. If you just want to visit all nodes in sorted order, use GLib.Tree.foreach() instead. If you really need to visit nodes in a different order, consider using an n-ary tree.

unref()[source]¶

Decrements the reference count of self 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 self will be released.

It is safe to call this function from any thread.

New in version 2.22.

upper_bound(key)[source]¶

Parameters:: key (object or None) – the key to calculate the upper bound for
Returns:: the tree node corresponding to the upper bound, or None if the tree is empty or has only keys lower than or equal to the searched key.
Return type:: GLib.TreeNode or None

Gets the upper bound node corresponding to the given key, or None if the tree is empty or all the nodes in the tree have keys that are lower than or equal to the searched key.

The upper bound is the first node that has its key strictly greater than the searched key.

New in version 2.68.