1/* 2 Red Black Trees 3 (C) 1999 Andrea Arcangeli <andrea@suse.de> 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 2 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program; if not, write to the Free Software 17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 19 linux/include/linux/rbtree.h 20 21 To use rbtrees you'll have to implement your own insert and search cores. 22 This will avoid us to use callbacks and to drop drammatically performances. 23 I know it's not the cleaner way, but in C (not in C++) to get 24 performances and genericity... 25 26 See Documentation/rbtree.txt for documentation and samples. 27*/ 28 29#ifndef _LINUX_RBTREE_H 30#define _LINUX_RBTREE_H 31 32#include <linux/kernel.h> 33#include <linux/stddef.h> 34 35struct rb_node { 36 unsigned long __rb_parent_color; 37 struct rb_node *rb_right; 38 struct rb_node *rb_left; 39} __attribute__((aligned(sizeof(long)))); 40 /* The alignment might seem pointless, but allegedly CRIS needs it */ 41 42struct rb_root { 43 struct rb_node *rb_node; 44}; 45 46 47#define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3)) 48 49#define RB_ROOT (struct rb_root) { NULL, } 50#define rb_entry(ptr, type, member) container_of(ptr, type, member) 51 52#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL) 53 54/* 'empty' nodes are nodes that are known not to be inserted in an rbtree */ 55#define RB_EMPTY_NODE(node) \ 56 ((node)->__rb_parent_color == (unsigned long)(node)) 57#define RB_CLEAR_NODE(node) \ 58 ((node)->__rb_parent_color = (unsigned long)(node)) 59 60 61extern void rb_insert_color(struct rb_node *, struct rb_root *); 62extern void rb_erase(struct rb_node *, struct rb_root *); 63 64 65/* Find logical next and previous nodes in a tree */ 66extern struct rb_node *rb_next(const struct rb_node *); 67extern struct rb_node *rb_prev(const struct rb_node *); 68extern struct rb_node *rb_first(const struct rb_root *); 69extern struct rb_node *rb_last(const struct rb_root *); 70 71/* Postorder iteration - always visit the parent after its children */ 72extern struct rb_node *rb_first_postorder(const struct rb_root *); 73extern struct rb_node *rb_next_postorder(const struct rb_node *); 74 75/* Fast replacement of a single node without remove/rebalance/add/rebalance */ 76extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, 77 struct rb_root *root); 78 79static inline void rb_link_node(struct rb_node * node, struct rb_node * parent, 80 struct rb_node ** rb_link) 81{ 82 node->__rb_parent_color = (unsigned long)parent; 83 node->rb_left = node->rb_right = NULL; 84 85 *rb_link = node; 86} 87 88#define rb_entry_safe(ptr, type, member) \ 89 ({ typeof(ptr) ____ptr = (ptr); \ 90 ____ptr ? rb_entry(____ptr, type, member) : NULL; \ 91 }) 92 93/** 94 * rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of 95 * given type safe against removal of rb_node entry 96 * 97 * @pos: the 'type *' to use as a loop cursor. 98 * @n: another 'type *' to use as temporary storage 99 * @root: 'rb_root *' of the rbtree. 100 * @field: the name of the rb_node field within 'type'. 101 */ 102#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \ 103 for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \ 104 pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \ 105 typeof(*pos), field); 1; }); \ 106 pos = n) 107 108#endif /* _LINUX_RBTREE_H */ 109