Current File : //backups/router/usr/lib/include/sys/tree.h
/* $NetBSD: tree.h,v 1.8 2004/03/28 19:38:30 provos Exp $ */
/* $OpenBSD: tree.h,v 1.7 2002/10/17 21:51:54 art Exp $ */
/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* 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_
#include <sys/cdefs.h>
/*
* This file defines data structures for different types of trees:
* splay trees and rank-balanced 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 rank-balanced tree is a binary search tree with an integer
* rank-difference as an attribute of each pointer from parent to child.
* The sum of the rank-differences on any path from a node down to null is
* the same, and defines the rank of that node. The rank of the null node
* is -1.
*
* Different additional conditions define different sorts of balanced trees,
* including "red-black" and "AVL" trees. The set of conditions applied here
* are the "weak-AVL" conditions of Haeupler, Sen and Tarjan presented in in
* "Rank Balanced Trees", ACM Transactions on Algorithms Volume 11 Issue 4 June
* 2015 Article No.: 30pp 1–26 https://doi.org/10.1145/2689412 (the HST paper):
* - every rank-difference is 1 or 2.
* - the rank of any leaf is 1.
*
* For historical reasons, rank differences that are even are associated
* with the color red (Rank-Even-Difference), and the child that a red edge
* points to is called a red child.
*
* Every operation on a rank-balanced tree is bounded as O(lg n).
* The maximum height of a rank-balanced 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 (/*CONSTCOND*/ 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 (/*CONSTCOND*/ 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 (/*CONSTCOND*/ 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 (/*CONSTCOND*/ 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 (/*CONSTCOND*/ 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 (/*CONSTCOND*/ 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 __unused __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 __unused __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 __unused __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 { \
__typeof(cmp(NULL, NULL)) __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; \
__typeof(cmp(NULL, NULL)) __comp; \
\
SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
__left = __right = &__node; \
\
while ((__comp = (cmp)(elm, (head)->sph_root)) != 0) { \
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))
/* Macros that define a rank-balanced tree */
#define RB_HEAD(name, type) \
struct name { \
struct type *rbh_root; /* root of the tree */ \
}
#define RB_INITIALIZER(root) \
{ NULL }
#define RB_INIT(root) do { \
(root)->rbh_root = NULL; \
} while (/*CONSTCOND*/ 0)
#define RB_ENTRY(type) \
struct { \
struct type *rbe_link[3]; \
}
/*
* With the expectation that any object of struct type has an
* address that is a multiple of 4, and that therefore the
* 2 least significant bits of a pointer to struct type are
* always zero, this implementation sets those bits to indicate
* that the left or right child of the tree node is "red".
*/
#define _RB_LINK(elm, dir, field) (elm)->field.rbe_link[dir]
#define _RB_UP(elm, field) _RB_LINK(elm, 0, field)
#define _RB_L ((__uintptr_t)1)
#define _RB_R ((__uintptr_t)2)
#define _RB_LR ((__uintptr_t)3)
#define _RB_BITS(elm) (*(__uintptr_t *)&elm)
#define _RB_BITSUP(elm, field) _RB_BITS(_RB_UP(elm, field))
#define _RB_PTR(elm) (__typeof(elm)) \
((__uintptr_t)elm & ~_RB_LR)
#define RB_PARENT(elm, field) _RB_PTR(_RB_UP(elm, field))
#define RB_LEFT(elm, field) _RB_LINK(elm, _RB_L, field)
#define RB_RIGHT(elm, field) _RB_LINK(elm, _RB_R, field)
#define RB_ROOT(head) (head)->rbh_root
#define RB_EMPTY(head) (RB_ROOT(head) == NULL)
#define RB_SET_PARENT(dst, src, field) do { \
_RB_BITSUP(dst, field) = (__uintptr_t)src | \
(_RB_BITSUP(dst, field) & _RB_LR); \
} while (/*CONSTCOND*/ 0)
#define RB_SET(elm, parent, field) do { \
_RB_UP(elm, field) = parent; \
RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL; \
} while (/*CONSTCOND*/ 0)
/*
* Either RB_AUGMENT or RB_AUGMENT_CHECK is invoked in a loop at the root of
* every modified subtree, from the bottom up to the root, to update augmented
* node data. RB_AUGMENT_CHECK returns true only when the update changes the
* node data, so that updating can be stopped short of the root when it returns
* false.
*/
#ifndef RB_AUGMENT_CHECK
#ifndef RB_AUGMENT
#define RB_AUGMENT_CHECK(x) 0
#else
#define RB_AUGMENT_CHECK(x) (RB_AUGMENT(x), 1)
#endif
#endif
#define RB_UPDATE_AUGMENT(elm, field) do { \
__typeof(elm) rb_update_tmp = (elm); \
while (RB_AUGMENT_CHECK(rb_update_tmp) && \
(rb_update_tmp = RB_PARENT(rb_update_tmp, field)) != NULL) \
; \
} while (0)
#define RB_SWAP_CHILD(head, par, out, in, field) do { \
if (par == NULL) \
RB_ROOT(head) = (in); \
else if ((out) == RB_LEFT(par, field)) \
RB_LEFT(par, field) = (in); \
else \
RB_RIGHT(par, field) = (in); \
} while (/*CONSTCOND*/ 0)
/*
* RB_ROTATE macro partially restructures the tree to improve balance. In the
* case when dir is _RB_L, tmp is a right child of elm. After rotation, elm
* is a left child of tmp, and the subtree that represented the items between
* them, which formerly hung to the left of tmp now hangs to the right of elm.
* The parent-child relationship between elm and its former parent is not
* changed; where this macro once updated those fields, that is now left to the
* caller of RB_ROTATE to clean up, so that a pair of rotations does not twice
* update the same pair of pointer fields with distinct values.
*/
#define RB_ROTATE(elm, tmp, dir, field) do { \
if ((_RB_LINK(elm, dir ^ _RB_LR, field) = \
_RB_LINK(tmp, dir, field)) != NULL) \
RB_SET_PARENT(_RB_LINK(tmp, dir, field), elm, field); \
_RB_LINK(tmp, dir, field) = (elm); \
RB_SET_PARENT(elm, tmp, field); \
} while (/*CONSTCOND*/ 0)
/* Generates prototypes and inline functions */
#define RB_PROTOTYPE(name, type, field, cmp) \
RB_PROTOTYPE_INTERNAL(name, type, field, cmp,)
#define RB_PROTOTYPE_STATIC(name, type, field, cmp) \
RB_PROTOTYPE_INTERNAL(name, type, field, cmp, __unused static)
#define RB_PROTOTYPE_INTERNAL(name, type, field, cmp, attr) \
RB_PROTOTYPE_RANK(name, type, attr) \
RB_PROTOTYPE_INSERT_COLOR(name, type, attr); \
RB_PROTOTYPE_REMOVE_COLOR(name, type, attr); \
RB_PROTOTYPE_INSERT_FINISH(name, type, attr); \
RB_PROTOTYPE_INSERT(name, type, attr); \
RB_PROTOTYPE_REMOVE(name, type, attr); \
RB_PROTOTYPE_FIND(name, type, attr); \
RB_PROTOTYPE_NFIND(name, type, attr); \
RB_PROTOTYPE_NEXT(name, type, attr); \
RB_PROTOTYPE_INSERT_NEXT(name, type, attr); \
RB_PROTOTYPE_PREV(name, type, attr); \
RB_PROTOTYPE_INSERT_PREV(name, type, attr); \
RB_PROTOTYPE_MINMAX(name, type, attr); \
RB_PROTOTYPE_REINSERT(name, type, attr);
#ifdef _RB_DIAGNOSTIC
#define RB_PROTOTYPE_RANK(name, type, attr) \
attr int name##_RB_RANK(struct type *);
#else
#define RB_PROTOTYPE_RANK(name, type, attr)
#endif
#define RB_PROTOTYPE_INSERT_COLOR(name, type, attr) \
attr struct type *name##_RB_INSERT_COLOR(struct name *, \
struct type *, struct type *)
#define RB_PROTOTYPE_REMOVE_COLOR(name, type, attr) \
attr struct type *name##_RB_REMOVE_COLOR(struct name *, \
struct type *, struct type *)
#define RB_PROTOTYPE_REMOVE(name, type, attr) \
attr struct type *name##_RB_REMOVE(struct name *, struct type *)
#define RB_PROTOTYPE_INSERT_FINISH(name, type, attr) \
attr struct type *name##_RB_INSERT_FINISH(struct name *, \
struct type *, struct type **, struct type *)
#define RB_PROTOTYPE_INSERT(name, type, attr) \
attr struct type *name##_RB_INSERT(struct name *, struct type *)
#define RB_PROTOTYPE_FIND(name, type, attr) \
attr struct type *name##_RB_FIND(struct name *, struct type *)
#define RB_PROTOTYPE_NFIND(name, type, attr) \
attr struct type *name##_RB_NFIND(struct name *, struct type *)
#define RB_PROTOTYPE_NEXT(name, type, attr) \
attr struct type *name##_RB_NEXT(struct type *)
#define RB_PROTOTYPE_INSERT_NEXT(name, type, attr) \
attr struct type *name##_RB_INSERT_NEXT(struct name *, \
struct type *, struct type *)
#define RB_PROTOTYPE_PREV(name, type, attr) \
attr struct type *name##_RB_PREV(struct type *)
#define RB_PROTOTYPE_INSERT_PREV(name, type, attr) \
attr struct type *name##_RB_INSERT_PREV(struct name *, \
struct type *, struct type *)
#define RB_PROTOTYPE_MINMAX(name, type, attr) \
attr struct type *name##_RB_MINMAX(struct name *, int)
#define RB_PROTOTYPE_REINSERT(name, type, attr) \
attr struct type *name##_RB_REINSERT(struct name *, struct type *)
/* Main rb operation.
* Moves node close to the key of elm to top
*/
#define RB_GENERATE(name, type, field, cmp) \
RB_GENERATE_INTERNAL(name, type, field, cmp,)
#define RB_GENERATE_STATIC(name, type, field, cmp) \
RB_GENERATE_INTERNAL(name, type, field, cmp, __unused static)
#define RB_GENERATE_INTERNAL(name, type, field, cmp, attr) \
RB_GENERATE_RANK(name, type, field, attr) \
RB_GENERATE_INSERT_COLOR(name, type, field, attr) \
RB_GENERATE_REMOVE_COLOR(name, type, field, attr) \
RB_GENERATE_INSERT_FINISH(name, type, field, attr) \
RB_GENERATE_INSERT(name, type, field, cmp, attr) \
RB_GENERATE_REMOVE(name, type, field, attr) \
RB_GENERATE_FIND(name, type, field, cmp, attr) \
RB_GENERATE_NFIND(name, type, field, cmp, attr) \
RB_GENERATE_NEXT(name, type, field, attr) \
RB_GENERATE_INSERT_NEXT(name, type, field, cmp, attr) \
RB_GENERATE_PREV(name, type, field, attr) \
RB_GENERATE_INSERT_PREV(name, type, field, cmp, attr) \
RB_GENERATE_MINMAX(name, type, field, attr) \
RB_GENERATE_REINSERT(name, type, field, cmp, attr)
#ifdef _RB_DIAGNOSTIC
#ifndef RB_AUGMENT
#define _RB_AUGMENT_VERIFY(x) RB_AUGMENT_CHECK(x)
#else
#define _RB_AUGMENT_VERIFY(x) 0
#endif
#define RB_GENERATE_RANK(name, type, field, attr) \
/* \
* Return the rank of the subtree rooted at elm, or -1 if the subtree \
* is not rank-balanced, or has inconsistent augmentation data.
*/ \
attr int \
name##_RB_RANK(struct type *elm) \
{ \
struct type *left, *right, *up; \
int left_rank, right_rank; \
\
if (elm == NULL) \
return (0); \
up = _RB_UP(elm, field); \
left = RB_LEFT(elm, field); \
left_rank = ((_RB_BITS(up) & _RB_L) ? 2 : 1) + \
name##_RB_RANK(left); \
right = RB_RIGHT(elm, field); \
right_rank = ((_RB_BITS(up) & _RB_R) ? 2 : 1) + \
name##_RB_RANK(right); \
if (left_rank != right_rank || \
(left_rank == 2 && left == NULL && right == NULL) || \
_RB_AUGMENT_VERIFY(elm)) \
return (-1); \
return (left_rank); \
}
#else
#define RB_GENERATE_RANK(name, type, field, attr)
#endif
#define RB_GENERATE_INSERT_COLOR(name, type, field, attr) \
attr struct type * \
name##_RB_INSERT_COLOR(struct name *head, \
struct type *parent, struct type *elm) \
{ \
/* \
* Initially, elm is a leaf. Either its parent was previously \
* a leaf, with two black null children, or an interior node \
* with a black non-null child and a red null child. The \
* balance criterion "the rank of any leaf is 1" precludes the \
* possibility of two red null children for the initial parent. \
* So the first loop iteration cannot lead to accessing an \
* uninitialized 'child', and a later iteration can only happen \
* when a value has been assigned to 'child' in the previous \
* one. \
*/ \
struct type *child, *child_up, *gpar; \
__uintptr_t elmdir, sibdir; \
\
do { \
/* the rank of the tree rooted at elm grew */ \
gpar = _RB_UP(parent, field); \
elmdir = RB_RIGHT(parent, field) == elm ? _RB_R : _RB_L; \
if (_RB_BITS(gpar) & elmdir) { \
/* shorten the parent-elm edge to rebalance */ \
_RB_BITSUP(parent, field) ^= elmdir; \
return (NULL); \
} \
sibdir = elmdir ^ _RB_LR; \
/* the other edge must change length */ \
_RB_BITSUP(parent, field) ^= sibdir; \
if ((_RB_BITS(gpar) & _RB_LR) == 0) { \
/* both edges now short, retry from parent */ \
child = elm; \
elm = parent; \
continue; \
} \
_RB_UP(parent, field) = gpar = _RB_PTR(gpar); \
if (_RB_BITSUP(elm, field) & elmdir) { \
/* \
* Exactly one of the edges descending from elm \
* is long. The long one is in the same \
* direction as the edge from parent to elm, \
* so change that by rotation. The edge from \
* parent to z was shortened above. Shorten \
* the long edge down from elm, and adjust \
* other edge lengths based on the downward \
* edges from 'child'. \
* \
* par par \
* / \ / \ \
* elm z / z \
* / \ child \
* / child / \ \
* / / \ elm \ \
* w / \ / \ y \
* x y w \ \
* x \
*/ \
RB_ROTATE(elm, child, elmdir, field); \
child_up = _RB_UP(child, field); \
if (_RB_BITS(child_up) & sibdir) \
_RB_BITSUP(parent, field) ^= elmdir; \
if (_RB_BITS(child_up) & elmdir) \
_RB_BITSUP(elm, field) ^= _RB_LR; \
else \
_RB_BITSUP(elm, field) ^= elmdir; \
/* if child is a leaf, don't augment elm, \
* since it is restored to be a leaf again. */ \
if ((_RB_BITS(child_up) & _RB_LR) == 0) \
elm = child; \
} else \
child = elm; \
\
/* \
* The long edge descending from 'child' points back \
* in the direction of 'parent'. Rotate to make \
* 'parent' a child of 'child', then make both edges \
* of 'child' short to rebalance. \
* \
* par child \
* / \ / \ \
* / z x par \
* child / \ \
* / \ / z \
* x \ y \
* y \
*/ \
RB_ROTATE(parent, child, sibdir, field); \
_RB_UP(child, field) = gpar; \
RB_SWAP_CHILD(head, gpar, parent, child, field); \
/* \
* Elements rotated down have new, smaller subtrees, \
* so update augmentation for them. \
*/ \
if (elm != child) \
(void)RB_AUGMENT_CHECK(elm); \
(void)RB_AUGMENT_CHECK(parent); \
return (child); \
} while ((parent = gpar) != NULL); \
return (NULL); \
}
#ifndef RB_STRICT_HST
/*
* In REMOVE_COLOR, the HST paper, in figure 3, in the single-rotate case, has
* 'parent' with one higher rank, and then reduces its rank if 'parent' has
* become a leaf. This implementation always has the parent in its new position
* with lower rank, to avoid the leaf check. Define RB_STRICT_HST to 1 to get
* the behavior that HST describes.
*/
#define RB_STRICT_HST 0
#endif
#define RB_GENERATE_REMOVE_COLOR(name, type, field, attr) \
attr struct type * \
name##_RB_REMOVE_COLOR(struct name *head, \
struct type *parent, struct type *elm) \
{ \
struct type *gpar, *sib, *up; \
__uintptr_t elmdir, sibdir; \
\
if (RB_RIGHT(parent, field) == elm && \
RB_LEFT(parent, field) == elm) { \
/* Deleting a leaf that is an only-child creates a \
* rank-2 leaf. Demote that leaf. */ \
_RB_UP(parent, field) = _RB_PTR(_RB_UP(parent, field)); \
elm = parent; \
if ((parent = _RB_UP(elm, field)) == NULL) \
return (NULL); \
} \
do { \
/* the rank of the tree rooted at elm shrank */ \
gpar = _RB_UP(parent, field); \
elmdir = RB_RIGHT(parent, field) == elm ? _RB_R : _RB_L; \
_RB_BITS(gpar) ^= elmdir; \
if (_RB_BITS(gpar) & elmdir) { \
/* lengthen the parent-elm edge to rebalance */ \
_RB_UP(parent, field) = gpar; \
return (NULL); \
} \
if (_RB_BITS(gpar) & _RB_LR) { \
/* shorten other edge, retry from parent */ \
_RB_BITS(gpar) ^= _RB_LR; \
_RB_UP(parent, field) = gpar; \
gpar = _RB_PTR(gpar); \
continue; \
} \
sibdir = elmdir ^ _RB_LR; \
sib = _RB_LINK(parent, sibdir, field); \
up = _RB_UP(sib, field); \
_RB_BITS(up) ^= _RB_LR; \
if ((_RB_BITS(up) & _RB_LR) == 0) { \
/* shorten edges descending from sib, retry */ \
_RB_UP(sib, field) = up; \
continue; \
} \
if ((_RB_BITS(up) & sibdir) == 0) { \
/* \
* The edge descending from 'sib' away from \
* 'parent' is long. The short edge descending \
* from 'sib' toward 'parent' points to 'elm*' \
* Rotate to make 'sib' a child of 'elm*' \
* then adjust the lengths of the edges \
* descending from 'sib' and 'elm*'. \
* \
* par par \
* / \ / \ \
* / sib elm \ \
* / / \ elm* \
* elm elm* \ / \ \
* / \ \ / \ \
* / \ z / \ \
* x y x sib \
* / \ \
* / z \
* y \
*/ \
elm = _RB_LINK(sib, elmdir, field); \
/* elm is a 1-child. First rotate at elm. */ \
RB_ROTATE(sib, elm, sibdir, field); \
up = _RB_UP(elm, field); \
_RB_BITSUP(parent, field) ^= \
(_RB_BITS(up) & elmdir) ? _RB_LR : elmdir; \
_RB_BITSUP(sib, field) ^= \
(_RB_BITS(up) & sibdir) ? _RB_LR : sibdir; \
_RB_BITSUP(elm, field) |= _RB_LR; \
} else { \
if ((_RB_BITS(up) & elmdir) == 0 && \
RB_STRICT_HST && elm != NULL) { \
/* if parent does not become a leaf, \
do not demote parent yet. */ \
_RB_BITSUP(parent, field) ^= sibdir; \
_RB_BITSUP(sib, field) ^= _RB_LR; \
} else if ((_RB_BITS(up) & elmdir) == 0) { \
/* demote parent. */ \
_RB_BITSUP(parent, field) ^= elmdir; \
_RB_BITSUP(sib, field) ^= sibdir; \
} else \
_RB_BITSUP(sib, field) ^= sibdir; \
elm = sib; \
} \
\
/* \
* The edge descending from 'elm' away from 'parent' \
* is short. Rotate to make 'parent' a child of 'elm', \
* then lengthen the short edges descending from \
* 'parent' and 'elm' to rebalance. \
* \
* par elm \
* / \ / \ \
* e \ / \ \
* elm / \ \
* / \ par s \
* / \ / \ \
* / \ e \ \
* x s x \
*/ \
RB_ROTATE(parent, elm, elmdir, field); \
RB_SET_PARENT(elm, gpar, field); \
RB_SWAP_CHILD(head, gpar, parent, elm, field); \
/* \
* An element rotated down, but not into the search \
* path has a new, smaller subtree, so update \
* augmentation for it. \
*/ \
if (sib != elm) \
(void)RB_AUGMENT_CHECK(sib); \
return (parent); \
} while (elm = parent, (parent = gpar) != NULL); \
return (NULL); \
}
#define _RB_AUGMENT_WALK(elm, match, field) \
do { \
if (match == elm) \
match = NULL; \
} while (RB_AUGMENT_CHECK(elm) && \
(elm = RB_PARENT(elm, field)) != NULL)
#define RB_GENERATE_REMOVE(name, type, field, attr) \
attr struct type * \
name##_RB_REMOVE(struct name *head, struct type *out) \
{ \
struct type *child, *in, *opar, *parent; \
\
child = RB_LEFT(out, field); \
in = RB_RIGHT(out, field); \
opar = _RB_UP(out, field); \
if (in == NULL || child == NULL) { \
in = child = (in == NULL ? child : in); \
parent = opar = _RB_PTR(opar); \
} else { \
parent = in; \
while (RB_LEFT(in, field)) \
in = RB_LEFT(in, field); \
RB_SET_PARENT(child, in, field); \
RB_LEFT(in, field) = child; \
child = RB_RIGHT(in, field); \
if (parent != in) { \
RB_SET_PARENT(parent, in, field); \
RB_RIGHT(in, field) = parent; \
parent = RB_PARENT(in, field); \
RB_LEFT(parent, field) = child; \
} \
_RB_UP(in, field) = opar; \
opar = _RB_PTR(opar); \
} \
RB_SWAP_CHILD(head, opar, out, in, field); \
if (child != NULL) \
_RB_UP(child, field) = parent; \
if (parent != NULL) { \
opar = name##_RB_REMOVE_COLOR(head, parent, child); \
/* if rotation has made 'parent' the root of the same \
* subtree as before, don't re-augment it. */ \
if (parent == in && RB_LEFT(parent, field) == NULL) { \
opar = NULL; \
parent = RB_PARENT(parent, field); \
} \
_RB_AUGMENT_WALK(parent, opar, field); \
if (opar != NULL) { \
/* \
* Elements rotated into the search path have \
* changed subtrees, so update augmentation for \
* them if AUGMENT_WALK didn't. \
*/ \
(void)RB_AUGMENT_CHECK(opar); \
(void)RB_AUGMENT_CHECK(RB_PARENT(opar, field)); \
} \
} \
return (out); \
}
#define RB_GENERATE_INSERT_FINISH(name, type, field, attr) \
/* Inserts a node into the RB tree */ \
attr struct type * \
name##_RB_INSERT_FINISH(struct name *head, struct type *parent, \
struct type **pptr, struct type *elm) \
{ \
struct type *tmp = NULL; \
\
RB_SET(elm, parent, field); \
*pptr = elm; \
if (parent != NULL) \
tmp = name##_RB_INSERT_COLOR(head, parent, elm); \
_RB_AUGMENT_WALK(elm, tmp, field); \
if (tmp != NULL) \
/* \
* An element rotated into the search path has a \
* changed subtree, so update augmentation for it if \
* AUGMENT_WALK didn't. \
*/ \
(void)RB_AUGMENT_CHECK(tmp); \
return (NULL); \
}
#define RB_GENERATE_INSERT(name, type, field, cmp, attr) \
/* Inserts a node into the RB tree */ \
attr struct type * \
name##_RB_INSERT(struct name *head, struct type *elm) \
{ \
struct type *tmp; \
struct type **tmpp = &RB_ROOT(head); \
struct type *parent = NULL; \
\
while ((tmp = *tmpp) != NULL) { \
parent = tmp; \
__typeof(cmp(NULL, NULL)) comp = (cmp)(elm, parent); \
if (comp < 0) \
tmpp = &RB_LEFT(parent, field); \
else if (comp > 0) \
tmpp = &RB_RIGHT(parent, field); \
else \
return (parent); \
} \
return (name##_RB_INSERT_FINISH(head, parent, tmpp, elm)); \
}
#define RB_GENERATE_FIND(name, type, field, cmp, attr) \
/* Finds the node with the same key as elm */ \
attr struct type * \
name##_RB_FIND(struct name *head, struct type *elm) \
{ \
struct type *tmp = RB_ROOT(head); \
__typeof(cmp(NULL, NULL)) comp; \
while (tmp) { \
comp = cmp(elm, tmp); \
if (comp < 0) \
tmp = RB_LEFT(tmp, field); \
else if (comp > 0) \
tmp = RB_RIGHT(tmp, field); \
else \
return (tmp); \
} \
return (NULL); \
}
#define RB_GENERATE_NFIND(name, type, field, cmp, attr) \
/* Finds the first node greater than or equal to the search key */ \
attr struct type * \
name##_RB_NFIND(struct name *head, struct type *elm) \
{ \
struct type *tmp = RB_ROOT(head); \
struct type *res = NULL; \
__typeof(cmp(NULL, NULL)) comp; \
while (tmp) { \
comp = cmp(elm, tmp); \
if (comp < 0) { \
res = tmp; \
tmp = RB_LEFT(tmp, field); \
} \
else if (comp > 0) \
tmp = RB_RIGHT(tmp, field); \
else \
return (tmp); \
} \
return (res); \
}
#define RB_GENERATE_NEXT(name, type, field, attr) \
/* ARGSUSED */ \
attr struct type * \
name##_RB_NEXT(struct type *elm) \
{ \
if (RB_RIGHT(elm, field)) { \
elm = RB_RIGHT(elm, field); \
while (RB_LEFT(elm, field)) \
elm = RB_LEFT(elm, field); \
} else { \
while (RB_PARENT(elm, field) && \
(elm == RB_RIGHT(RB_PARENT(elm, field), field))) \
elm = RB_PARENT(elm, field); \
elm = RB_PARENT(elm, field); \
} \
return (elm); \
}
#if defined(_KERNEL) && defined(DIAGNOSTIC)
#define _RB_ORDER_CHECK(cmp, lo, hi) do { \
KASSERT((cmp)(lo, hi) < 0, ("out of order insertion")); \
} while (0)
#else
#define _RB_ORDER_CHECK(cmp, lo, hi) do {} while (0)
#endif
#define RB_GENERATE_INSERT_NEXT(name, type, field, cmp, attr) \
/* Inserts a node into the next position in the RB tree */ \
attr struct type * \
name##_RB_INSERT_NEXT(struct name *head, \
struct type *elm, struct type *next) \
{ \
struct type *tmp; \
struct type **tmpp = &RB_RIGHT(elm, field); \
\
_RB_ORDER_CHECK(cmp, elm, next); \
if (name##_RB_NEXT(elm) != NULL) \
_RB_ORDER_CHECK(cmp, next, name##_RB_NEXT(elm)); \
while ((tmp = *tmpp) != NULL) { \
elm = tmp; \
tmpp = &RB_LEFT(elm, field); \
} \
return (name##_RB_INSERT_FINISH(head, elm, tmpp, next)); \
}
#define RB_GENERATE_PREV(name, type, field, attr) \
/* ARGSUSED */ \
attr struct type * \
name##_RB_PREV(struct type *elm) \
{ \
if (RB_LEFT(elm, field)) { \
elm = RB_LEFT(elm, field); \
while (RB_RIGHT(elm, field)) \
elm = RB_RIGHT(elm, field); \
} else { \
while (RB_PARENT(elm, field) && \
(elm == RB_LEFT(RB_PARENT(elm, field), field))) \
elm = RB_PARENT(elm, field); \
elm = RB_PARENT(elm, field); \
} \
return (elm); \
}
#define RB_GENERATE_INSERT_PREV(name, type, field, cmp, attr) \
/* Inserts a node into the prev position in the RB tree */ \
attr struct type * \
name##_RB_INSERT_PREV(struct name *head, \
struct type *elm, struct type *prev) \
{ \
struct type *tmp; \
struct type **tmpp = &RB_LEFT(elm, field); \
\
_RB_ORDER_CHECK(cmp, prev, elm); \
if (name##_RB_PREV(elm) != NULL) \
_RB_ORDER_CHECK(cmp, name##_RB_PREV(elm), prev); \
while ((tmp = *tmpp) != NULL) { \
elm = tmp; \
tmpp = &RB_RIGHT(elm, field); \
} \
return (name##_RB_INSERT_FINISH(head, elm, tmpp, prev)); \
}
#define RB_GENERATE_MINMAX(name, type, field, attr) \
attr struct type * \
name##_RB_MINMAX(struct name *head, int val) \
{ \
struct type *tmp = RB_ROOT(head); \
struct type *parent = NULL; \
while (tmp) { \
parent = tmp; \
if (val < 0) \
tmp = RB_LEFT(tmp, field); \
else \
tmp = RB_RIGHT(tmp, field); \
} \
return (parent); \
}
#define RB_GENERATE_REINSERT(name, type, field, cmp, attr) \
attr struct type * \
name##_RB_REINSERT(struct name *head, struct type *elm) \
{ \
struct type *cmpelm; \
if (((cmpelm = RB_PREV(name, head, elm)) != NULL && \
cmp(cmpelm, elm) >= 0) || \
((cmpelm = RB_NEXT(name, head, elm)) != NULL && \
cmp(elm, cmpelm) >= 0)) { \
/* XXXLAS: Remove/insert is heavy handed. */ \
RB_REMOVE(name, head, elm); \
return (RB_INSERT(name, head, elm)); \
} \
return (NULL); \
} \
#define RB_NEGINF -1
#define RB_INF 1
#define RB_INSERT(name, x, y) name##_RB_INSERT(x, y)
#define RB_INSERT_NEXT(name, x, y, z) name##_RB_INSERT_NEXT(x, y, z)
#define RB_INSERT_PREV(name, x, y, z) name##_RB_INSERT_PREV(x, y, z)
#define RB_REMOVE(name, x, y) name##_RB_REMOVE(x, y)
#define RB_FIND(name, x, y) name##_RB_FIND(x, y)
#define RB_NFIND(name, x, y) name##_RB_NFIND(x, y)
#define RB_NEXT(name, x, y) name##_RB_NEXT(y)
#define RB_PREV(name, x, y) name##_RB_PREV(y)
#define RB_MIN(name, x) name##_RB_MINMAX(x, RB_NEGINF)
#define RB_MAX(name, x) name##_RB_MINMAX(x, RB_INF)
#define RB_REINSERT(name, x, y) name##_RB_REINSERT(x, y)
#define RB_FOREACH(x, name, head) \
for ((x) = RB_MIN(name, head); \
(x) != NULL; \
(x) = name##_RB_NEXT(x))
#define RB_FOREACH_FROM(x, name, y) \
for ((x) = (y); \
((x) != NULL) && ((y) = name##_RB_NEXT(x), (x) != NULL); \
(x) = (y))
#define RB_FOREACH_SAFE(x, name, head, y) \
for ((x) = RB_MIN(name, head); \
((x) != NULL) && ((y) = name##_RB_NEXT(x), (x) != NULL); \
(x) = (y))
#define RB_FOREACH_REVERSE(x, name, head) \
for ((x) = RB_MAX(name, head); \
(x) != NULL; \
(x) = name##_RB_PREV(x))
#define RB_FOREACH_REVERSE_FROM(x, name, y) \
for ((x) = (y); \
((x) != NULL) && ((y) = name##_RB_PREV(x), (x) != NULL); \
(x) = (y))
#define RB_FOREACH_REVERSE_SAFE(x, name, head, y) \
for ((x) = RB_MAX(name, head); \
((x) != NULL) && ((y) = name##_RB_PREV(x), (x) != NULL); \
(x) = (y))
#endif /* _SYS_TREE_H_ */
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