rbtree.c File Reference

Implementation of a redblack tree. More...

#include "config.h"
#include "log.h"
#include "fptr_wlist.h"
#include "util/rbtree.h"

Macros

#define BLACK   0
 Node colour black.
 
#define RED   1
 Node colour red.
 

Functions

static void rbtree_rotate_left (rbtree_type *rbtree, rbnode_type *node)
 rotate subtree left (to preserve redblack property)
 
static void rbtree_rotate_right (rbtree_type *rbtree, rbnode_type *node)
 rotate subtree right (to preserve redblack property)
 
static void rbtree_insert_fixup (rbtree_type *rbtree, rbnode_type *node)
 Fixup node colours when insert happened.
 
static void rbtree_delete_fixup (rbtree_type *rbtree, rbnode_type *child, rbnode_type *child_parent)
 Fixup node colours when delete happened.
 
rbtree_typerbtree_create (int(*cmpf)(const void *, const void *))
 Create new tree (malloced) with given key compare function. More...
 
void rbtree_init (rbtree_type *rbtree, int(*cmpf)(const void *, const void *))
 Init a new tree (malloced by caller) with given key compare function. More...
 
rbnode_typerbtree_insert (rbtree_type *rbtree, rbnode_type *data)
 Insert data into the tree. More...
 
rbnode_typerbtree_search (rbtree_type *rbtree, const void *key)
 Find key in tree. More...
 
static void swap_int8 (uint8_t *x, uint8_t *y)
 helpers for delete: swap node colours
 
static void swap_np (rbnode_type **x, rbnode_type **y)
 helpers for delete: swap node pointers
 
static void change_parent_ptr (rbtree_type *rbtree, rbnode_type *parent, rbnode_type *old, rbnode_type *new)
 Update parent pointers of child trees of 'parent'.
 
static void change_child_ptr (rbnode_type *child, rbnode_type *old, rbnode_type *new)
 Update parent pointer of a node 'child'.
 
rbnode_typerbtree_delete (rbtree_type *rbtree, const void *key)
 Delete element from tree. More...
 
int rbtree_find_less_equal (rbtree_type *rbtree, const void *key, rbnode_type **result)
 Find, but match does not have to be exact. More...
 
rbnode_typerbtree_first (rbtree_type *rbtree)
 Returns first (smallest) node in the tree. More...
 
rbnode_typerbtree_last (rbtree_type *rbtree)
 Returns last (largest) node in the tree. More...
 
rbnode_typerbtree_next (rbnode_type *node)
 Returns next larger node in the tree. More...
 
rbnode_typerbtree_previous (rbnode_type *node)
 Returns previous smaller node in the tree. More...
 
static void traverse_post (void(*func)(rbnode_type *, void *), void *arg, rbnode_type *node)
 recursive descent traverse
 
void traverse_postorder (rbtree_type *tree, void(*func)(rbnode_type *, void *), void *arg)
 Call function for all elements in the redblack tree, such that leaf elements are called before parent elements. More...
 

Variables

rbnode_type rbtree_null_node
 the NULL node, global alloc More...
 

Detailed Description

Implementation of a redblack tree.

Function Documentation

◆ rbtree_create()

rbtree_type* rbtree_create ( int(*)(const void *, const void *)  cmpf)

Create new tree (malloced) with given key compare function.

Parameters
cmpfcompare function (like strcmp) takes pointers to two keys.
Returns
: new tree, empty.

References rbtree_init().

Referenced by anchors_create(), iter_apply_cfg(), macro_store_create(), main(), and outside_network_create().

◆ rbtree_init()

◆ rbtree_insert()

◆ rbtree_search()

◆ rbtree_delete()

◆ rbtree_find_less_equal()

int rbtree_find_less_equal ( rbtree_type rbtree,
const void *  key,
rbnode_type **  result 
)

Find, but match does not have to be exact.

Parameters
rbtreetree to find in.
keykey to find position of.
resultset to the exact node if present, otherwise to element that precedes the position of key in the tree. NULL if no smaller element.
Returns
: true if exact match in result. Else result points to <= element, or NULL if key is smaller than the smallest key.

References rbtree_type::cmp, fptr_ok, fptr_whitelist_rbtree_cmp(), rbnode_type::key, rbnode_type::left, log_assert, RBTREE_NULL, rbnode_type::right, and rbtree_type::root.

Referenced by addr_tree_lookup(), anchors_lookup(), auth_zone_find_less_equal(), az_find_domain(), forwards_lookup(), local_zones_find_le(), local_zones_tags_lookup(), name_tree_lookup(), name_tree_next_root(), neg_closest_data(), neg_closest_data_parent(), neg_closest_zone_parent(), rbtree_search(), and reuse_tcp_find().

◆ rbtree_first()

◆ rbtree_last()

rbnode_type* rbtree_last ( rbtree_type rbtree)

Returns last (largest) node in the tree.

Parameters
rbtreetree
Returns
: largest element or NULL if tree empty.

References RBTREE_NULL, rbnode_type::right, and rbtree_type::root.

Referenced by az_nsec3_find_cover(), neg_nsec3_getnc(), and reuse_tcp_select_id().

◆ rbtree_next()

◆ rbtree_previous()

rbnode_type* rbtree_previous ( rbnode_type rbtree)

Returns previous smaller node in the tree.

Parameters
rbtreetree
Returns
: previous smaller element or NULL if no previous in tree.

References rbnode_type::left, rbnode_type::parent, RBTREE_NULL, and rbnode_type::right.

Referenced by neg_find_nsec(), respip_sockaddr_delete(), and reuse_tcp_find().

◆ traverse_postorder()

void traverse_postorder ( rbtree_type tree,
void(*)(rbnode_type *, void *)  func,
void *  arg 
)

Call function for all elements in the redblack tree, such that leaf elements are called before parent elements.

So that all elements can be safely free()d. Note that your function must not remove the nodes from the tree. Since that may trigger rebalances of the rbtree.

Parameters
treethe tree
funcfunction called with element and user arg. The function must not alter the rbtree.
arguser argument.

References rbtree_type::root, and traverse_post().

Referenced by anchors_delete(), apply_axfr(), apply_http(), auth_zone_delete(), auth_zone_read_zonefile(), auth_zones_delete(), dns64_deinit(), infra_adjust(), infra_delete(), iter_deinit(), local_zones_delete(), locks_free(), macro_store_delete(), neg_cache_delete(), outside_network_delete(), respip_set_delete(), reuse_cb_and_decommission(), reuse_del_readwait(), tcl_list_delete(), and views_delete().

Variable Documentation

◆ rbtree_null_node

rbnode_type rbtree_null_node
Initial value:
= {
NULL,
}
#define BLACK
Node colour black.
Definition: rbtree.c:48
#define RBTREE_NULL
The nullpointer, points to empty node.
Definition: rbtree.h:69

the NULL node, global alloc

the global empty node