Red-Black Trees

A Red-Black Tree container. More...

Files
file	rbtree.c
	Initialize a Red-Black Tree.

Macros
#define	RTEMS_RBTREE_INITIALIZER_EMPTY(name)   RBTREE_INITIALIZER_EMPTY(name)
	RBTree initializer for an empty rbtree with designator name.
#define	RTEMS_RBTREE_DEFINE_EMPTY(name)   RBTREE_DEFINE_EMPTY(name)
	RBTree definition for an empty rbtree with designator name.

Typedefs
typedef RBTree_Node	rtems_rbtree_node
typedef RBTree_Control	rtems_rbtree_control
typedef long	rtems_rbtree_compare_result
	Integer type for compare results. More...
typedef rtems_rbtree_compare_result(*	rtems_rbtree_compare) (const RBTree_Node *first, const RBTree_Node *second)
	Compares two red-black tree nodes. More...

Functions
void	rtems_rbtree_initialize (rtems_rbtree_control *the_rbtree, rtems_rbtree_compare compare, void *starting_address, size_t number_nodes, size_t node_size, bool is_unique)
	Initialize a RBTree header. More...
RTEMS_INLINE_ROUTINE void	rtems_rbtree_initialize_empty (rtems_rbtree_control *the_rbtree)
	Initialize this RBTree as Empty. More...
RTEMS_INLINE_ROUTINE void	rtems_rbtree_set_off_tree (rtems_rbtree_node *node)
	Set off RBtree. More...
RTEMS_INLINE_ROUTINE bool	rtems_rbtree_is_node_off_tree (const rtems_rbtree_node *node)
	Is the Node off RBTree. More...
RTEMS_INLINE_ROUTINE rtems_rbtree_node *	rtems_rbtree_root (const rtems_rbtree_control *the_rbtree)
	Return pointer to RBTree root. More...
RTEMS_INLINE_ROUTINE rtems_rbtree_node *	rtems_rbtree_min (const rtems_rbtree_control *the_rbtree)
	Returns the minimum node of the red-black tree. More...
RTEMS_INLINE_ROUTINE rtems_rbtree_node *	rtems_rbtree_max (const rtems_rbtree_control *the_rbtree)
	Returns the maximum node of the red-black tree. More...
RTEMS_INLINE_ROUTINE rtems_rbtree_node *	rtems_rbtree_left (const rtems_rbtree_node *the_node)
	Return pointer to the left child node from this node. More...
RTEMS_INLINE_ROUTINE rtems_rbtree_node *	rtems_rbtree_right (const rtems_rbtree_node *the_node)
	Return pointer to the right child node from this node. More...
RTEMS_INLINE_ROUTINE rtems_rbtree_node *	rtems_rbtree_parent (const rtems_rbtree_node *the_node)
	Returns a pointer to the parent of this node. More...
RTEMS_INLINE_ROUTINE bool	rtems_rbtree_is_empty (const rtems_rbtree_control *the_rbtree)
	Is the RBTree empty. More...
RTEMS_INLINE_ROUTINE bool	rtems_rbtree_is_min (const rtems_rbtree_control *the_rbtree, const rtems_rbtree_node *the_node)
	Is this the minimum node on the RBTree. More...
RTEMS_INLINE_ROUTINE bool	rtems_rbtree_is_max (const rtems_rbtree_control *the_rbtree, const rtems_rbtree_node *the_node)
	Is this the maximum node on the RBTree. More...
RTEMS_INLINE_ROUTINE bool	rtems_rbtree_is_root (const rtems_rbtree_node *the_node)
	Checks if this node is the root node of a red-black tree. More...
RTEMS_INLINE_ROUTINE bool	rtems_rbtree_is_equal (rtems_rbtree_compare_result compare_result)
RTEMS_INLINE_ROUTINE bool	rtems_rbtree_is_greater (rtems_rbtree_compare_result compare_result)
RTEMS_INLINE_ROUTINE bool	rtems_rbtree_is_lesser (rtems_rbtree_compare_result compare_result)
rtems_rbtree_node *	rtems_rbtree_find (const rtems_rbtree_control *the_rbtree, const rtems_rbtree_node *the_node, rtems_rbtree_compare compare, bool is_unique)
	Tries to find a node for the specified key in the tree. More...
RTEMS_INLINE_ROUTINE rtems_rbtree_node *	rtems_rbtree_predecessor (const rtems_rbtree_node *node)
	Returns the predecessor of a node. More...
RTEMS_INLINE_ROUTINE rtems_rbtree_node *	rtems_rbtree_successor (const rtems_rbtree_node *node)
	Returns the successor of a node. More...
RTEMS_INLINE_ROUTINE void	rtems_rbtree_extract (rtems_rbtree_control *the_rbtree, rtems_rbtree_node *the_node)
	Extracts (removes) the node from the red-black tree. More...
RTEMS_INLINE_ROUTINE rtems_rbtree_node *	rtems_rbtree_get_min (rtems_rbtree_control *the_rbtree)
	Gets a node with the minimum key value from the red-black tree. More...
RTEMS_INLINE_ROUTINE rtems_rbtree_node *	rtems_rbtree_get_max (rtems_rbtree_control *the_rbtree)
	Gets a node with the maximal key value from the red-black tree. More...
RTEMS_INLINE_ROUTINE rtems_rbtree_node *	rtems_rbtree_peek_min (const rtems_rbtree_control *the_rbtree)
	Peek at the min node on a rbtree. More...
RTEMS_INLINE_ROUTINE rtems_rbtree_node *	rtems_rbtree_peek_max (const rtems_rbtree_control *the_rbtree)
	Peek at the max node on a rbtree. More...
rtems_rbtree_node *	rtems_rbtree_insert (RBTree_Control *the_rbtree, RBTree_Node *the_node, rtems_rbtree_compare compare, bool is_unique)
	Inserts the node into the red-black tree. More...

Detailed Description

A Red-Black Tree container.

The red-black tree container offers no internal protection against concurrent access. The user must ensure that at most one thread at once can access a red-black tree instance.

Typedef Documentation

rtems_rbtree_compare

typedef rtems_rbtree_compare_result( * rtems_rbtree_compare) (const RBTree_Node *first, const RBTree_Node *second)

Compares two red-black tree nodes.

Parameters

[in]	first	The first node.
[in]	second	The second node.

Return values

positive	The key value of the first node is greater than the one of the second node.
0	The key value of the first node is equal to the one of the second node.
negative	The key value of the first node is less than the one of the second node.

rtems_rbtree_compare_result

typedef long rtems_rbtree_compare_result

Integer type for compare results.

The type is large enough to represent pointers and 32-bit signed integers.

See also

rtems_rbtree_compare.

rtems_rbtree_control

rtems_rbtree_control

The rbtree's control anchors the rbtree.

rtems_rbtree_node

rtems_rbtree_node

A node that can be manipulated in the rbtree.

Function Documentation

rtems_rbtree_extract()

RTEMS_INLINE_ROUTINE void rtems_rbtree_extract	(	rtems_rbtree_control *	the_rbtree,
		rtems_rbtree_node *	the_node
	)

Extracts (removes) the node from the red-black tree.

This function does not set the node off-tree. In the case this is desired, then call _RBTree_Set_off_tree() after the extraction.

In the case the node to extract is not a node of the tree, then this function yields unpredictable results.

Parameters

[in,out]	the_rbtree	The red-black tree control.
[out]	the_node	The node to extract.

rtems_rbtree_find()

rtems_rbtree_node* rtems_rbtree_find	(	const rtems_rbtree_control *	the_rbtree,
		const rtems_rbtree_node *	the_node,
		rtems_rbtree_compare	compare,
		bool	is_unique
	)

Tries to find a node for the specified key in the tree.

Parameters

[in]	the_rbtree	The red-black tree control.
[in]	the_node	A node specifying the key.
[in]	compare	The node compare function.
[in]	is_unique	If true, then return the first node with a key equal to the one of the node specified if it exits, else return the last node if it exists.

Return values

node	A node corresponding to the key. If the tree is not unique and contains duplicate keys, the set of duplicate keys acts as FIFO.
NULL	No node exists in the tree for the key.

rtems_rbtree_get_max()

RTEMS_INLINE_ROUTINE rtems_rbtree_node* rtems_rbtree_get_max

(

rtems_rbtree_control *

the_rbtree

)

Gets a node with the maximal key value from the red-black tree.

This function extracts a node with the maximum key value from tree and returns a pointer to that node if it exists. In case multiple nodes with a maximum key value exist, then they are extracted in LIFO order.

Parameters

[in]

the_rbtree

The red-black tree control.

Return values

NULL	The tree is empty.
node	A node with the maximal key value on the tree.

rtems_rbtree_get_min()

RTEMS_INLINE_ROUTINE rtems_rbtree_node* rtems_rbtree_get_min

(

rtems_rbtree_control *

the_rbtree

)

Gets a node with the minimum key value from the red-black tree.

This function extracts a node with the minimum key value from tree and returns a pointer to that node if it exists. In case multiple nodes with a minimum key value exist, then they are extracted in FIFO order.

Parameters

[in]

the_rbtree

The red-black tree control.

Return values

NULL	The tree is empty.
node	A node with the minimal key value on the tree.

rtems_rbtree_initialize()

void rtems_rbtree_initialize	(	rtems_rbtree_control *	the_rbtree,
		rtems_rbtree_compare	compare,
		void *	starting_address,
		size_t	number_nodes,
		size_t	node_size,
		bool	is_unique
	)

Initialize a RBTree header.

This routine initializes the_rbtree structure to manage the contiguous array of number_nodes nodes which starts at starting_address. Each node is of node_size bytes.

Parameters

[in]	the_rbtree	is the pointer to rbtree header
[in]	compare	The node compare function.
[in]	starting_address	is the starting address of first node
[in]	number_nodes	is the number of nodes in rbtree
[in]	node_size	is the size of node in bytes
[in]	is_unique	If true, then reject nodes with a duplicate key, else otherwise.

rtems_rbtree_initialize_empty()

RTEMS_INLINE_ROUTINE void rtems_rbtree_initialize_empty

(

rtems_rbtree_control *

the_rbtree

)

Initialize this RBTree as Empty.

This routine initializes the_rbtree to contain zero nodes.

rtems_rbtree_insert()

rtems_rbtree_node* rtems_rbtree_insert	(	RBTree_Control *	the_rbtree,
		RBTree_Node *	the_node,
		rtems_rbtree_compare	compare,
		bool	is_unique
	)

Inserts the node into the red-black tree.

In case the node is already a node of a tree, then this function yields unpredictable results.

Parameters

[in]	the_rbtree	The red-black tree control.
[in]	the_node	The node to insert.
[in]	compare	The node compare function.
[in]	is_unique	If true, then reject nodes with a duplicate key, else insert nodes in FIFO order in case the key value is equal to existing nodes.

Return values

NULL	Successfully inserted.
existing_node	This is a unique insert and there exists a node with an equal key in the tree already.

rtems_rbtree_is_empty()

RTEMS_INLINE_ROUTINE bool rtems_rbtree_is_empty

(

const rtems_rbtree_control *

the_rbtree

)

Is the RBTree empty.

This function returns true if there a no nodes on the_rbtree and false otherwise.

rtems_rbtree_is_max()

RTEMS_INLINE_ROUTINE bool rtems_rbtree_is_max	(	const rtems_rbtree_control *	the_rbtree,
		const rtems_rbtree_node *	the_node
	)

Is this the maximum node on the RBTree.

This function returns true if the_node is the max node on the_rbtree and false otherwise.

rtems_rbtree_is_min()

RTEMS_INLINE_ROUTINE bool rtems_rbtree_is_min	(	const rtems_rbtree_control *	the_rbtree,
		const rtems_rbtree_node *	the_node
	)

Is this the minimum node on the RBTree.

This function returns true if the_node is the min node on the_rbtree and false otherwise.

rtems_rbtree_is_node_off_tree()

RTEMS_INLINE_ROUTINE bool rtems_rbtree_is_node_off_tree

(

const rtems_rbtree_node *

node

)

Is the Node off RBTree.

This function returns true if the node is not on a rbtree. A node is off rbtree if the next and previous fields are set to NULL.

rtems_rbtree_is_root()

RTEMS_INLINE_ROUTINE bool rtems_rbtree_is_root

(

const rtems_rbtree_node *

the_node

)

Checks if this node is the root node of a red-black tree.

The root node may change after insert or extract operations. In case the node is not a node of a tree, then this function yields unpredictable results.

Parameters

the_node

The node of interest.

Return values

true	the_node is the root node.
false	the_node is not the root node.

See also

_RBTree_Root().

rtems_rbtree_left()

RTEMS_INLINE_ROUTINE rtems_rbtree_node* rtems_rbtree_left

(

const rtems_rbtree_node *

the_node

)

Return pointer to the left child node from this node.

This function returns a pointer to the left child node of the_node.

rtems_rbtree_max()

RTEMS_INLINE_ROUTINE rtems_rbtree_node* rtems_rbtree_max

(

const rtems_rbtree_control *

the_rbtree

)

Returns the maximum node of the red-black tree.

Parameters

the_rbtree

The red-black tree control.

Return values

node	The maximum node.
NULL	The red-black tree is empty.

rtems_rbtree_min()

RTEMS_INLINE_ROUTINE rtems_rbtree_node* rtems_rbtree_min

(

const rtems_rbtree_control *

the_rbtree

)

Returns the minimum node of the red-black tree.

Parameters

the_rbtree

The red-black tree control.

Return values

node	The minimum node.
NULL	The red-black tree is empty.

rtems_rbtree_parent()

RTEMS_INLINE_ROUTINE rtems_rbtree_node* rtems_rbtree_parent

(

const rtems_rbtree_node *

the_node

)

Returns a pointer to the parent of this node.

The node must have a parent, thus it is invalid to use this function for the root node or a node that is not part of a tree. To test for the root node compare with _RBTree_Root() or use _RBTree_Is_root().

Parameters

the_node

The node of interest.

Return values

parent	The parent of this node.
undefined	The node is the root node or not part of a tree.

rtems_rbtree_peek_max()

RTEMS_INLINE_ROUTINE rtems_rbtree_node* rtems_rbtree_peek_max

(

const rtems_rbtree_control *

the_rbtree

)

Peek at the max node on a rbtree.

This function returns a pointer to the max node from the_rbtree without changing the tree. If the_rbtree is empty, then NULL is returned.

rtems_rbtree_peek_min()

RTEMS_INLINE_ROUTINE rtems_rbtree_node* rtems_rbtree_peek_min

(

const rtems_rbtree_control *

the_rbtree

)

Peek at the min node on a rbtree.

This function returns a pointer to the min node from the_rbtree without changing the tree. If the_rbtree is empty, then NULL is returned.

rtems_rbtree_predecessor()

RTEMS_INLINE_ROUTINE rtems_rbtree_node* rtems_rbtree_predecessor

(

const rtems_rbtree_node *

node

)

Returns the predecessor of a node.

Parameters

node	is the node.

Return values

node	The predecessor node.
NULL	The predecessor does not exist.

rtems_rbtree_right()

RTEMS_INLINE_ROUTINE rtems_rbtree_node* rtems_rbtree_right

(

const rtems_rbtree_node *

the_node

)

Return pointer to the right child node from this node.

This function returns a pointer to the right child node of the_node.

rtems_rbtree_root()

RTEMS_INLINE_ROUTINE rtems_rbtree_node* rtems_rbtree_root

(

const rtems_rbtree_control *

the_rbtree

)

Return pointer to RBTree root.

This function returns a pointer to the root node of the_rbtree.

rtems_rbtree_set_off_tree()

RTEMS_INLINE_ROUTINE void rtems_rbtree_set_off_tree

(

rtems_rbtree_node *

node

)

Set off RBtree.

This function sets the next and previous fields of the node to NULL indicating the node is not part of any rbtree.

rtems_rbtree_successor()

RTEMS_INLINE_ROUTINE rtems_rbtree_node* rtems_rbtree_successor

(

const rtems_rbtree_node *

node

)

Returns the successor of a node.

Parameters

node	is the node.

Return values

node	The successor node.
NULL	The successor does not exist.