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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:53:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:53:30 +0000 |
commit | 2c7cac91ed6e7db0f6937923d2b57f97dbdbc337 (patch) | |
tree | c05dc0f8e6aa3accc84e3e5cffc933ed94941383 /lib/openbsd-tree.h | |
parent | Initial commit. (diff) | |
download | frr-upstream/8.4.4.tar.xz frr-upstream/8.4.4.zip |
Adding upstream version 8.4.4.upstream/8.4.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/openbsd-tree.h')
-rw-r--r-- | lib/openbsd-tree.h | 580 |
1 files changed, 580 insertions, 0 deletions
diff --git a/lib/openbsd-tree.h b/lib/openbsd-tree.h new file mode 100644 index 0000000..832a101 --- /dev/null +++ b/lib/openbsd-tree.h @@ -0,0 +1,580 @@ +/* $OpenBSD: tree.h,v 1.14 2015/05/25 03:07:49 deraadt Exp $ */ +/* + * Copyright 2002 Niels Provos <provos@citi.umich.edu> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _SYS_TREE_H_ +#define _SYS_TREE_H_ + +#ifdef __cplusplus +extern "C" { +#endif + +/* + * This file defines data structures for different types of trees: + * splay trees and red-black trees. + * + * A splay tree is a self-organizing data structure. Every operation + * on the tree causes a splay to happen. The splay moves the requested + * node to the root of the tree and partly rebalances it. + * + * This has the benefit that request locality causes faster lookups as + * the requested nodes move to the top of the tree. On the other hand, + * every lookup causes memory writes. + * + * The Balance Theorem bounds the total access time for m operations + * and n inserts on an initially empty tree as O((m + n)lg n). The + * amortized cost for a sequence of m accesses to a splay tree is O(lg n); + * + * A red-black tree is a binary search tree with the node color as an + * extra attribute. It fulfills a set of conditions: + * - every search path from the root to a leaf consists of the + * same number of black nodes, + * - each red node (except for the root) has a black parent, + * - each leaf node is black. + * + * Every operation on a red-black tree is bounded as O(lg n). + * The maximum height of a red-black tree is 2lg (n+1). + */ + +#define SPLAY_HEAD(name, type) \ + struct name { \ + struct type *sph_root; /* root of the tree */ \ + } + +#define SPLAY_INITIALIZER(root) \ + { \ + NULL \ + } + +#define SPLAY_INIT(root) \ + do { \ + (root)->sph_root = NULL; \ + } while (0) + +#define SPLAY_ENTRY(type) \ + struct { \ + struct type *spe_left; /* left element */ \ + struct type *spe_right; /* right element */ \ + } + +#define SPLAY_LEFT(elm, field) (elm)->field.spe_left +#define SPLAY_RIGHT(elm, field) (elm)->field.spe_right +#define SPLAY_ROOT(head) (head)->sph_root +#define SPLAY_EMPTY(head) (SPLAY_ROOT(head) == NULL) + +/* SPLAY_ROTATE_{LEFT,RIGHT} expect that tmp hold SPLAY_{RIGHT,LEFT} */ +#define SPLAY_ROTATE_RIGHT(head, tmp, field) \ + do { \ + SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(tmp, field); \ + SPLAY_RIGHT(tmp, field) = (head)->sph_root; \ + (head)->sph_root = tmp; \ + } while (0) + +#define SPLAY_ROTATE_LEFT(head, tmp, field) \ + do { \ + SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(tmp, field); \ + SPLAY_LEFT(tmp, field) = (head)->sph_root; \ + (head)->sph_root = tmp; \ + } while (0) + +#define SPLAY_LINKLEFT(head, tmp, field) \ + do { \ + SPLAY_LEFT(tmp, field) = (head)->sph_root; \ + tmp = (head)->sph_root; \ + (head)->sph_root = SPLAY_LEFT((head)->sph_root, field); \ + } while (0) + +#define SPLAY_LINKRIGHT(head, tmp, field) \ + do { \ + SPLAY_RIGHT(tmp, field) = (head)->sph_root; \ + tmp = (head)->sph_root; \ + (head)->sph_root = SPLAY_RIGHT((head)->sph_root, field); \ + } while (0) + +#define SPLAY_ASSEMBLE(head, node, left, right, field) \ + do { \ + SPLAY_RIGHT(left, field) = \ + SPLAY_LEFT((head)->sph_root, field); \ + SPLAY_LEFT(right, field) = \ + SPLAY_RIGHT((head)->sph_root, field); \ + SPLAY_LEFT((head)->sph_root, field) = \ + SPLAY_RIGHT(node, field); \ + SPLAY_RIGHT((head)->sph_root, field) = \ + SPLAY_LEFT(node, field); \ + } while (0) + +/* Generates prototypes and inline functions */ + +#define SPLAY_PROTOTYPE(name, type, field, cmp) \ + void name##_SPLAY(struct name *, struct type *); \ + void name##_SPLAY_MINMAX(struct name *, int); \ + struct type *name##_SPLAY_INSERT(struct name *, struct type *); \ + struct type *name##_SPLAY_REMOVE(struct name *, struct type *); \ + \ + /* Finds the node with the same key as elm */ \ + static __inline struct type *name##_SPLAY_FIND(struct name *head, \ + struct type *elm) \ + { \ + if (SPLAY_EMPTY(head)) \ + return (NULL); \ + name##_SPLAY(head, elm); \ + if ((cmp)(elm, (head)->sph_root) == 0) \ + return (head->sph_root); \ + return (NULL); \ + } \ + \ + static __inline struct type *name##_SPLAY_NEXT(struct name *head, \ + struct type *elm) \ + { \ + name##_SPLAY(head, elm); \ + if (SPLAY_RIGHT(elm, field) != NULL) { \ + elm = SPLAY_RIGHT(elm, field); \ + while (SPLAY_LEFT(elm, field) != NULL) { \ + elm = SPLAY_LEFT(elm, field); \ + } \ + } else \ + elm = NULL; \ + return (elm); \ + } \ + \ + static __inline struct type *name##_SPLAY_MIN_MAX(struct name *head, \ + int val) \ + { \ + name##_SPLAY_MINMAX(head, val); \ + return (SPLAY_ROOT(head)); \ + } + +/* Main splay operation. + * Moves node close to the key of elm to top + */ +#define SPLAY_GENERATE(name, type, field, cmp) \ + struct type *name##_SPLAY_INSERT(struct name *head, struct type *elm) \ + { \ + if (SPLAY_EMPTY(head)) { \ + SPLAY_LEFT(elm, field) = SPLAY_RIGHT(elm, field) = \ + NULL; \ + } else { \ + int __comp; \ + name##_SPLAY(head, elm); \ + __comp = (cmp)(elm, (head)->sph_root); \ + if (__comp < 0) { \ + SPLAY_LEFT(elm, field) = \ + SPLAY_LEFT((head)->sph_root, field); \ + SPLAY_RIGHT(elm, field) = (head)->sph_root; \ + SPLAY_LEFT((head)->sph_root, field) = NULL; \ + } else if (__comp > 0) { \ + SPLAY_RIGHT(elm, field) = \ + SPLAY_RIGHT((head)->sph_root, field); \ + SPLAY_LEFT(elm, field) = (head)->sph_root; \ + SPLAY_RIGHT((head)->sph_root, field) = NULL; \ + } else \ + return ((head)->sph_root); \ + } \ + (head)->sph_root = (elm); \ + return (NULL); \ + } \ + \ + struct type *name##_SPLAY_REMOVE(struct name *head, struct type *elm) \ + { \ + struct type *__tmp; \ + if (SPLAY_EMPTY(head)) \ + return (NULL); \ + name##_SPLAY(head, elm); \ + if ((cmp)(elm, (head)->sph_root) == 0) { \ + if (SPLAY_LEFT((head)->sph_root, field) == NULL) { \ + (head)->sph_root = \ + SPLAY_RIGHT((head)->sph_root, field); \ + } else { \ + __tmp = SPLAY_RIGHT((head)->sph_root, field); \ + (head)->sph_root = \ + SPLAY_LEFT((head)->sph_root, field); \ + name##_SPLAY(head, elm); \ + SPLAY_RIGHT((head)->sph_root, field) = __tmp; \ + } \ + return (elm); \ + } \ + return (NULL); \ + } \ + \ + void name##_SPLAY(struct name *head, struct type *elm) \ + { \ + struct type __node, *__left, *__right, *__tmp; \ + int __comp; \ + \ + SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = \ + NULL; \ + __left = __right = &__node; \ + \ + while ((__comp = (cmp)(elm, (head)->sph_root))) { \ + if (__comp < 0) { \ + __tmp = SPLAY_LEFT((head)->sph_root, field); \ + if (__tmp == NULL) \ + break; \ + if ((cmp)(elm, __tmp) < 0) { \ + SPLAY_ROTATE_RIGHT(head, __tmp, \ + field); \ + if (SPLAY_LEFT((head)->sph_root, \ + field) \ + == NULL) \ + break; \ + } \ + SPLAY_LINKLEFT(head, __right, field); \ + } else if (__comp > 0) { \ + __tmp = SPLAY_RIGHT((head)->sph_root, field); \ + if (__tmp == NULL) \ + break; \ + if ((cmp)(elm, __tmp) > 0) { \ + SPLAY_ROTATE_LEFT(head, __tmp, field); \ + if (SPLAY_RIGHT((head)->sph_root, \ + field) \ + == NULL) \ + break; \ + } \ + SPLAY_LINKRIGHT(head, __left, field); \ + } \ + } \ + SPLAY_ASSEMBLE(head, &__node, __left, __right, field); \ + } \ + \ + /* Splay with either the minimum or the maximum element \ + * Used to find minimum or maximum element in tree. \ + */ \ + void name##_SPLAY_MINMAX(struct name *head, int __comp) \ + { \ + struct type __node, *__left, *__right, *__tmp; \ + \ + SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = \ + NULL; \ + __left = __right = &__node; \ + \ + while (1) { \ + if (__comp < 0) { \ + __tmp = SPLAY_LEFT((head)->sph_root, field); \ + if (__tmp == NULL) \ + break; \ + if (__comp < 0) { \ + SPLAY_ROTATE_RIGHT(head, __tmp, \ + field); \ + if (SPLAY_LEFT((head)->sph_root, \ + field) \ + == NULL) \ + break; \ + } \ + SPLAY_LINKLEFT(head, __right, field); \ + } else if (__comp > 0) { \ + __tmp = SPLAY_RIGHT((head)->sph_root, field); \ + if (__tmp == NULL) \ + break; \ + if (__comp > 0) { \ + SPLAY_ROTATE_LEFT(head, __tmp, field); \ + if (SPLAY_RIGHT((head)->sph_root, \ + field) \ + == NULL) \ + break; \ + } \ + SPLAY_LINKRIGHT(head, __left, field); \ + } \ + } \ + SPLAY_ASSEMBLE(head, &__node, __left, __right, field); \ + } + +#define SPLAY_NEGINF -1 +#define SPLAY_INF 1 + +#define SPLAY_INSERT(name, x, y) name##_SPLAY_INSERT(x, y) +#define SPLAY_REMOVE(name, x, y) name##_SPLAY_REMOVE(x, y) +#define SPLAY_FIND(name, x, y) name##_SPLAY_FIND(x, y) +#define SPLAY_NEXT(name, x, y) name##_SPLAY_NEXT(x, y) +#define SPLAY_MIN(name, x) \ + (SPLAY_EMPTY(x) ? NULL : name##_SPLAY_MIN_MAX(x, SPLAY_NEGINF)) +#define SPLAY_MAX(name, x) \ + (SPLAY_EMPTY(x) ? NULL : name##_SPLAY_MIN_MAX(x, SPLAY_INF)) + +#define SPLAY_FOREACH(x, name, head) \ + for ((x) = SPLAY_MIN(name, head); (x) != NULL; \ + (x) = SPLAY_NEXT(name, head, x)) + +/* + * Copyright (c) 2016 David Gwynne <dlg@openbsd.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#define RB_BLACK 0 +#define RB_RED 1 + +struct rb_type { + int (*t_compare)(const void *, const void *); + void (*t_augment)(void *); + unsigned int t_offset; /* offset of rb_entry in type */ +}; + +struct rbt_tree { + struct rb_entry *rbt_root; +}; + +struct rb_entry { + struct rb_entry *rbt_parent; + struct rb_entry *rbt_left; + struct rb_entry *rbt_right; + unsigned int rbt_color; +}; + +#define RB_HEAD(_name, _type) \ + struct _name { \ + struct rbt_tree rbh_root; \ + } + +#define RB_ENTRY(_type) struct rb_entry + +static inline void _rb_init(struct rbt_tree *rbt) +{ + rbt->rbt_root = NULL; +} + +static inline int _rb_empty(const struct rbt_tree *rbt) +{ + return (rbt->rbt_root == NULL); +} + +void *_rb_insert(const struct rb_type *, struct rbt_tree *, void *); +void *_rb_remove(const struct rb_type *, struct rbt_tree *, void *); +void *_rb_find(const struct rb_type *, const struct rbt_tree *, const void *); +void *_rb_nfind(const struct rb_type *, const struct rbt_tree *, const void *); +void *_rb_root(const struct rb_type *, const struct rbt_tree *); +void *_rb_min(const struct rb_type *, const struct rbt_tree *); +void *_rb_max(const struct rb_type *, const struct rbt_tree *); +void *_rb_next(const struct rb_type *, void *); +void *_rb_prev(const struct rb_type *, void *); +void *_rb_left(const struct rb_type *, void *); +void *_rb_right(const struct rb_type *, void *); +void *_rb_parent(const struct rb_type *, void *); +void _rb_set_left(const struct rb_type *, void *, void *); +void _rb_set_right(const struct rb_type *, void *, void *); +void _rb_set_parent(const struct rb_type *, void *, void *); +void _rb_poison(const struct rb_type *, void *, unsigned long); +int _rb_check(const struct rb_type *, void *, unsigned long); + +#define RB_INITIALIZER(_head) { { NULL } } + +#define RB_PROTOTYPE(_name, _type, _field, _cmp) \ + extern const struct rb_type *const _name##_RB_TYPE; \ + \ + __attribute__((__unused__)) static inline void _name##_RB_INIT( \ + struct _name *head) \ + { \ + _rb_init(&head->rbh_root); \ + } \ + \ + __attribute__((__unused__)) static inline struct _type \ + *_name##_RB_INSERT(struct _name *head, struct _type *elm) \ + { \ + return (struct _type *)_rb_insert(_name##_RB_TYPE, \ + &head->rbh_root, elm); \ + } \ + \ + __attribute__((__unused__)) static inline struct _type \ + *_name##_RB_REMOVE(struct _name *head, struct _type *elm) \ + { \ + return (struct _type *)_rb_remove(_name##_RB_TYPE, \ + &head->rbh_root, elm); \ + } \ + \ + __attribute__((__unused__)) static inline struct _type \ + *_name##_RB_FIND(const struct _name *head, \ + const struct _type *key) \ + { \ + return (struct _type *)_rb_find(_name##_RB_TYPE, \ + &head->rbh_root, key); \ + } \ + \ + __attribute__((__unused__)) static inline struct _type \ + *_name##_RB_NFIND(const struct _name *head, \ + const struct _type *key) \ + { \ + return (struct _type *)_rb_nfind(_name##_RB_TYPE, \ + &head->rbh_root, key); \ + } \ + \ + __attribute__((__unused__)) static inline struct _type \ + *_name##_RB_ROOT(const struct _name *head) \ + { \ + return (struct _type *)_rb_root(_name##_RB_TYPE, \ + &head->rbh_root); \ + } \ + \ + __attribute__((__unused__)) static inline int _name##_RB_EMPTY( \ + const struct _name *head) \ + { \ + return _rb_empty(&head->rbh_root); \ + } \ + \ + __attribute__((__unused__)) static inline struct _type \ + *_name##_RB_MIN(const struct _name *head) \ + { \ + return (struct _type *)_rb_min(_name##_RB_TYPE, \ + &head->rbh_root); \ + } \ + \ + __attribute__((__unused__)) static inline struct _type \ + *_name##_RB_MAX(const struct _name *head) \ + { \ + return (struct _type *)_rb_max(_name##_RB_TYPE, \ + &head->rbh_root); \ + } \ + \ + __attribute__((__unused__)) static inline struct _type \ + *_name##_RB_NEXT(struct _type *elm) \ + { \ + return (struct _type *)_rb_next(_name##_RB_TYPE, elm); \ + } \ + \ + __attribute__((__unused__)) static inline struct _type \ + *_name##_RB_PREV(struct _type *elm) \ + { \ + return (struct _type *)_rb_prev(_name##_RB_TYPE, elm); \ + } \ + \ + __attribute__((__unused__)) static inline struct _type \ + *_name##_RB_LEFT(struct _type *elm) \ + { \ + return (struct _type *)_rb_left(_name##_RB_TYPE, elm); \ + } \ + \ + __attribute__((__unused__)) static inline struct _type \ + *_name##_RB_RIGHT(struct _type *elm) \ + { \ + return (struct _type *)_rb_right(_name##_RB_TYPE, elm); \ + } \ + \ + __attribute__((__unused__)) static inline struct _type \ + *_name##_RB_PARENT(struct _type *elm) \ + { \ + return (struct _type *)_rb_parent(_name##_RB_TYPE, elm); \ + } \ + \ + __attribute__((__unused__)) static inline void _name##_RB_SET_LEFT( \ + struct _type *elm, struct _type *left) \ + { \ + _rb_set_left(_name##_RB_TYPE, elm, left); \ + } \ + \ + __attribute__((__unused__)) static inline void _name##_RB_SET_RIGHT( \ + struct _type *elm, struct _type *right) \ + { \ + _rb_set_right(_name##_RB_TYPE, elm, right); \ + } \ + \ + __attribute__((__unused__)) static inline void _name##_RB_SET_PARENT( \ + struct _type *elm, struct _type *parent) \ + { \ + _rb_set_parent(_name##_RB_TYPE, elm, parent); \ + } \ + \ + __attribute__((__unused__)) static inline void _name##_RB_POISON( \ + struct _type *elm, unsigned long poison) \ + { \ + _rb_poison(_name##_RB_TYPE, elm, poison); \ + } \ + \ + __attribute__((__unused__)) static inline int _name##_RB_CHECK( \ + struct _type *elm, unsigned long poison) \ + { \ + return _rb_check(_name##_RB_TYPE, elm, poison); \ + } + +#define RB_GENERATE_INTERNAL(_name, _type, _field, _cmp, _aug) \ + static int _name##_RB_COMPARE(const void *lptr, const void *rptr) \ + { \ + const struct _type *l = lptr, *r = rptr; \ + return _cmp(l, r); \ + } \ + static const struct rb_type _name##_RB_INFO = { \ + _name##_RB_COMPARE, _aug, offsetof(struct _type, _field), \ + }; \ + const struct rb_type *const _name##_RB_TYPE = &_name##_RB_INFO; + +#define RB_GENERATE_AUGMENT(_name, _type, _field, _cmp, _aug) \ + static void _name##_RB_AUGMENT(void *ptr) \ + { \ + struct _type *p = ptr; \ + return _aug(p); \ + } \ + RB_GENERATE_INTERNAL(_name, _type, _field, _cmp, _name##_RB_AUGMENT) + +#define RB_GENERATE(_name, _type, _field, _cmp) \ + RB_GENERATE_INTERNAL(_name, _type, _field, _cmp, NULL) + +#define RB_INIT(_name, _head) _name##_RB_INIT(_head) +#define RB_INSERT(_name, _head, _elm) _name##_RB_INSERT(_head, _elm) +#define RB_REMOVE(_name, _head, _elm) _name##_RB_REMOVE(_head, _elm) +#define RB_FIND(_name, _head, _key) _name##_RB_FIND(_head, _key) +#define RB_NFIND(_name, _head, _key) _name##_RB_NFIND(_head, _key) +#define RB_ROOT(_name, _head) _name##_RB_ROOT(_head) +#define RB_EMPTY(_name, _head) _name##_RB_EMPTY(_head) +#define RB_MIN(_name, _head) _name##_RB_MIN(_head) +#define RB_MAX(_name, _head) _name##_RB_MAX(_head) +#define RB_NEXT(_name, _elm) _name##_RB_NEXT(_elm) +#define RB_PREV(_name, _elm) _name##_RB_PREV(_elm) +#define RB_LEFT(_name, _elm) _name##_RB_LEFT(_elm) +#define RB_RIGHT(_name, _elm) _name##_RB_RIGHT(_elm) +#define RB_PARENT(_name, _elm) _name##_RB_PARENT(_elm) +#define RB_SET_LEFT(_name, _elm, _l) _name##_RB_SET_LEFT(_elm, _l) +#define RB_SET_RIGHT(_name, _elm, _r) _name##_RB_SET_RIGHT(_elm, _r) +#define RB_SET_PARENT(_name, _elm, _p) _name##_RB_SET_PARENT(_elm, _p) +#define RB_POISON(_name, _elm, _p) _name##_RB_POISON(_elm, _p) +#define RB_CHECK(_name, _elm, _p) _name##_RB_CHECK(_elm, _p) + +#define RB_FOREACH(_e, _name, _head) \ + for ((_e) = RB_MIN(_name, (_head)); (_e) != NULL; \ + (_e) = RB_NEXT(_name, (_e))) + +#define RB_FOREACH_SAFE(_e, _name, _head, _n) \ + for ((_e) = RB_MIN(_name, (_head)); \ + (_e) != NULL && ((_n) = RB_NEXT(_name, (_e)), 1); (_e) = (_n)) + +#define RB_FOREACH_REVERSE(_e, _name, _head) \ + for ((_e) = RB_MAX(_name, (_head)); (_e) != NULL; \ + (_e) = RB_PREV(_name, (_e))) + +#define RB_FOREACH_REVERSE_SAFE(_e, _name, _head, _n) \ + for ((_e) = RB_MAX(_name, (_head)); \ + (_e) != NULL && ((_n) = RB_PREV(_name, (_e)), 1); (_e) = (_n)) + +#ifdef __cplusplus +} +#endif + +#endif /* _SYS_TREE_H_ */ |