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-rw-r--r--lib/openbsd-tree.h548
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diff --git a/lib/openbsd-tree.h b/lib/openbsd-tree.h
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+++ b/lib/openbsd-tree.h
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+// SPDX-License-Identifier: ISC AND BSD-2-Clause
+/* $OpenBSD: tree.h,v 1.14 2015/05/25 03:07:49 deraadt Exp $ */
+/*
+ * Copyright 2002 Niels Provos <provos@citi.umich.edu>
+ */
+
+#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>
+ */
+
+#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_ */
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