152 lines
5.4 KiB
C
152 lines
5.4 KiB
C
/*
|
|
Red Black Trees
|
|
(C) 1999 Andrea Arcangeli <andrea@suse.de>
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program 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 General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
|
|
linux/include/linux/rbtree.h
|
|
|
|
To use rbtrees you'll have to implement your own insert and search cores.
|
|
This will avoid us to use callbacks and to drop drammatically performances.
|
|
I know it's not the cleaner way, but in C (not in C++) to get
|
|
performances and genericity...
|
|
|
|
See Documentation/rbtree.txt for documentation and samples.
|
|
*/
|
|
|
|
#ifndef _LINUX_RBTREE_H
|
|
#define _LINUX_RBTREE_H
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/stddef.h>
|
|
#include <linux/rcupdate.h>
|
|
|
|
struct rb_node {
|
|
unsigned long __rb_parent_color;
|
|
struct rb_node *rb_right;
|
|
struct rb_node *rb_left;
|
|
} __attribute__((aligned(sizeof(long))));
|
|
/* The alignment might seem pointless, but allegedly CRIS needs it */
|
|
|
|
struct rb_root {
|
|
struct rb_node *rb_node;
|
|
};
|
|
|
|
/*
|
|
* Leftmost-cached rbtrees.
|
|
*
|
|
* We do not cache the rightmost node based on footprint
|
|
* size vs number of potential users that could benefit
|
|
* from O(1) rb_last(). Just not worth it, users that want
|
|
* this feature can always implement the logic explicitly.
|
|
* Furthermore, users that want to cache both pointers may
|
|
* find it a bit asymmetric, but that's ok.
|
|
*/
|
|
struct rb_root_cached {
|
|
struct rb_root rb_root;
|
|
struct rb_node *rb_leftmost;
|
|
};
|
|
|
|
#define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3))
|
|
|
|
#define RB_ROOT (struct rb_root) { NULL, }
|
|
#define RB_ROOT_CACHED (struct rb_root_cached) { {NULL, }, NULL }
|
|
#define rb_entry(ptr, type, member) container_of(ptr, type, member)
|
|
|
|
#define RB_EMPTY_ROOT(root) (READ_ONCE((root)->rb_node) == NULL)
|
|
|
|
/* 'empty' nodes are nodes that are known not to be inserted in an rbtree */
|
|
#define RB_EMPTY_NODE(node) \
|
|
((node)->__rb_parent_color == (unsigned long)(node))
|
|
#define RB_CLEAR_NODE(node) \
|
|
((node)->__rb_parent_color = (unsigned long)(node))
|
|
|
|
|
|
extern void rb_insert_color(struct rb_node *, struct rb_root *);
|
|
extern void rb_erase(struct rb_node *, struct rb_root *);
|
|
|
|
|
|
/* Find logical next and previous nodes in a tree */
|
|
extern struct rb_node *rb_next(const struct rb_node *);
|
|
extern struct rb_node *rb_prev(const struct rb_node *);
|
|
extern struct rb_node *rb_first(const struct rb_root *);
|
|
extern struct rb_node *rb_last(const struct rb_root *);
|
|
|
|
extern void rb_insert_color_cached(struct rb_node *,
|
|
struct rb_root_cached *, bool);
|
|
extern void rb_erase_cached(struct rb_node *node, struct rb_root_cached *);
|
|
/* Same as rb_first(), but O(1) */
|
|
#define rb_first_cached(root) (root)->rb_leftmost
|
|
|
|
/* Postorder iteration - always visit the parent after its children */
|
|
extern struct rb_node *rb_first_postorder(const struct rb_root *);
|
|
extern struct rb_node *rb_next_postorder(const struct rb_node *);
|
|
|
|
/* Fast replacement of a single node without remove/rebalance/add/rebalance */
|
|
extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
|
|
struct rb_root *root);
|
|
extern void rb_replace_node_rcu(struct rb_node *victim, struct rb_node *new,
|
|
struct rb_root *root);
|
|
extern void rb_replace_node_cached(struct rb_node *victim, struct rb_node *new,
|
|
struct rb_root_cached *root);
|
|
|
|
static inline void rb_link_node(struct rb_node *node, struct rb_node *parent,
|
|
struct rb_node **rb_link)
|
|
{
|
|
node->__rb_parent_color = (unsigned long)parent;
|
|
node->rb_left = node->rb_right = NULL;
|
|
|
|
*rb_link = node;
|
|
}
|
|
|
|
static inline void rb_link_node_rcu(struct rb_node *node, struct rb_node *parent,
|
|
struct rb_node **rb_link)
|
|
{
|
|
node->__rb_parent_color = (unsigned long)parent;
|
|
node->rb_left = node->rb_right = NULL;
|
|
|
|
rcu_assign_pointer(*rb_link, node);
|
|
}
|
|
|
|
#define rb_entry_safe(ptr, type, member) \
|
|
({ typeof(ptr) ____ptr = (ptr); \
|
|
____ptr ? rb_entry(____ptr, type, member) : NULL; \
|
|
})
|
|
|
|
/**
|
|
* rbtree_postorder_for_each_entry_safe - iterate in post-order over rb_root of
|
|
* given type allowing the backing memory of @pos to be invalidated
|
|
*
|
|
* @pos: the 'type *' to use as a loop cursor.
|
|
* @n: another 'type *' to use as temporary storage
|
|
* @root: 'rb_root *' of the rbtree.
|
|
* @field: the name of the rb_node field within 'type'.
|
|
*
|
|
* rbtree_postorder_for_each_entry_safe() provides a similar guarantee as
|
|
* list_for_each_entry_safe() and allows the iteration to continue independent
|
|
* of changes to @pos by the body of the loop.
|
|
*
|
|
* Note, however, that it cannot handle other modifications that re-order the
|
|
* rbtree it is iterating over. This includes calling rb_erase() on @pos, as
|
|
* rb_erase() may rebalance the tree, causing us to miss some nodes.
|
|
*/
|
|
#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \
|
|
for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \
|
|
pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \
|
|
typeof(*pos), field); 1; }); \
|
|
pos = n)
|
|
|
|
#endif /* _LINUX_RBTREE_H */
|