avltree、bstree、rbtree和Splaytree

具體參考：https://github.com/nfs-ganesha/nfs-ganesha

/*
 * libtree.h - this file is part of Libtree.
 *
 * Copyright (C) 2010 Franck Bui-Huu <fbuihuu@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; version 2 of the
 * License.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */
#ifndef _LIBTREE_H
#define _LIBTREE_H

#include <stdint.h>
#include <stddef.h>

/*
 * The definition has been stolen from the Linux kernel.
 */
#ifdef __GNUC__
#define bstree_container_of(node, type, member) ({			\
	const struct bstree_node *__mptr = (node);			\
	(type *)( (char *)__mptr - offsetof(type,member) );})
#define rbtree_container_of(node, type, member) ({			\
	const struct rbtree_node *__mptr = (node);			\
	(type *)( (char *)__mptr - offsetof(type,member) );})
#define avltree_container_of(node, type, member) ({			\
	const struct avltree_node *__mptr = (node);			\
	(type *)( (char *)__mptr - offsetof(type,member) );})
#define splaytree_container_of(node, type, member) ({			\
	const struct splaytree_node *__mptr = (node);			\
	(type *)( (char *)__mptr - offsetof(type,member) );})
#else
#define bstree_container_of(node, type, member)			\
	((type *)((char *)(node) - offsetof(type, member)))
#define rbtree_container_of(node, type, member)			\
	((type *)((char *)(node) - offsetof(type, member)))
#define avltree_container_of(node, type, member)			\
	((type *)((char *)(node) - offsetof(type, member)))
#define splaytree_container_of(node, type, member)			\
	((type *)((char *)(node) - offsetof(type, member)))
#endif				/* __GNUC__ */

/*
 * Threaded binary search tree
 */
#ifdef UINTPTR_MAX

struct bstree_node {
	uintptr_t left, right;
} __attribute__ ((aligned(2)));

#else

struct bstree_node {
	struct bstree_node *left, *right;
	unsigned left_is_thread:1;
	unsigned right_is_thread:1;
};

#endif				/* UINTPTR_MAX */

typedef int (*bstree_cmp_fn_t) (const struct bstree_node *,
				const struct bstree_node *);

struct bstree {
	struct bstree_node *root;
	bstree_cmp_fn_t cmp_fn;
	struct bstree_node *first, *last;
	uint64_t reserved[4];
};

struct bstree_node *bstree_first(const struct bstree *tree);
struct bstree_node *bstree_last(const struct bstree *tree);
struct bstree_node *bstree_next(const struct bstree_node *node);
struct bstree_node *bstree_prev(const struct bstree_node *node);

struct bstree_node *bstree_lookup(const struct bstree_node *key,
				  const struct bstree *tree);
struct bstree_node *bstree_insert(struct bstree_node *node,
				  struct bstree *tree);
void bstree_remove(struct bstree_node *node, struct bstree *tree);
void bstree_replace(struct bstree_node *old, struct bstree_node *new,
		    struct bstree *tree);
int bstree_init(struct bstree *tree, bstree_cmp_fn_t cmp, unsigned long flags);

/*
 * Red-black tree
 */
enum rb_color {
	RB_BLACK,
	RB_RED,
};

#ifdef UINTPTR_MAX

struct rbtree_node {
	struct rbtree_node *left, *right;
	uintptr_t parent;
} __attribute__ ((aligned(2)));

#else

struct rbtree_node {
	struct rbtree_node *left, *right;
	struct rbtree_node *parent;
	enum rb_color color;
};

#endif				/* UINTPTR_MAX */

typedef int (*rbtree_cmp_fn_t) (const struct rbtree_node *,
				const struct rbtree_node *);

struct rbtree {
	struct rbtree_node *root;
	rbtree_cmp_fn_t cmp_fn;
	struct rbtree_node *first, *last;
	uint64_t reserved[4];
};

struct rbtree_node *rbtree_first(const struct rbtree *tree);
struct rbtree_node *rbtree_last(const struct rbtree *tree);
struct rbtree_node *rbtree_next(const struct rbtree_node *node);
struct rbtree_node *rbtree_prev(const struct rbtree_node *node);

struct rbtree_node *rbtree_lookup(const struct rbtree_node *key,
				  const struct rbtree *tree);
struct rbtree_node *rbtree_insert(struct rbtree_node *node,
				  struct rbtree *tree);
void rbtree_remove(struct rbtree_node *node, struct rbtree *tree);
void rbtree_replace(struct rbtree_node *old, struct rbtree_node *new,
		    struct rbtree *tree);
int rbtree_init(struct rbtree *tree, rbtree_cmp_fn_t cmp, unsigned long flags);

/*
 * AVL tree
 */
#if defined UINTPTR_MAX && UINTPTR_MAX == UINT64_MAX

struct avltree_node {
	struct avltree_node *left, *right;
	uintptr_t parent;	/* balance factor [0:4] */
} __attribute__ ((aligned(8)));

#else

struct avltree_node {
	struct avltree_node *left, *right;
	struct avltree_node *parent;
	signed balance:3;	/* balance factor [-2:+2] */
};

#endif

typedef int (*avltree_cmp_fn_t) (const struct avltree_node *,
				 const struct avltree_node *);

struct avltree {
	struct avltree_node *root;
	avltree_cmp_fn_t cmp_fn;
	int height;
	struct avltree_node *first, *last;
	uint64_t size;
#if 0
	uint64_t reserved[4];
#endif
};

struct avltree_node *avltree_first(const struct avltree *tree);
struct avltree_node *avltree_last(const struct avltree *tree);
struct avltree_node *avltree_next(const struct avltree_node *node);
struct avltree_node *avltree_prev(const struct avltree_node *node);
uint64_t avltree_size(const struct avltree *tree);
struct avltree_node *avltree_lookup(const struct avltree_node *key,
				    const struct avltree *tree);
struct avltree_node *avltree_inf(const struct avltree_node *key,
				 const struct avltree *tree);
struct avltree_node *avltree_sup(const struct avltree_node *key,
				 const struct avltree *tree);
struct avltree_node *avltree_insert(struct avltree_node *node,
				    struct avltree *tree);
void avltree_remove(struct avltree_node *node, struct avltree *tree);
void avltree_replace(struct avltree_node *old, struct avltree_node *new,
		     struct avltree *tree);
int avltree_init(struct avltree *tree, avltree_cmp_fn_t cmp,
		 unsigned long flags);

/*
 * Splay tree
 */
#ifdef UINTPTR_MAX

struct splaytree_node {
	uintptr_t left, right;
} __attribute__ ((aligned(2)));

#else

struct splaytree_node {
	struct splaytree_node *left, *right;
	unsigned left_is_thread:1;
	unsigned right_is_thread:1;
};

#endif

typedef int (*splaytree_cmp_fn_t) (const struct splaytree_node *,
				   const struct splaytree_node *);

struct splaytree {
	struct splaytree_node *root;
	struct splaytree_node *first, *last;
	splaytree_cmp_fn_t cmp_fn;
	uint64_t reserved[4];
};

struct splaytree_node *splaytree_first(const struct splaytree *tree);
struct splaytree_node *splaytree_last(const struct splaytree *tree);
struct splaytree_node *splaytree_next(const struct splaytree_node *node);
struct splaytree_node *splaytree_prev(const struct splaytree_node *node);

struct splaytree_node *splaytree_lookup(const struct splaytree_node *key,
					struct splaytree *tree);
struct splaytree_node *splaytree_insert(struct splaytree_node *node,
					struct splaytree *tree);
void splaytree_remove(struct splaytree_node *node, struct splaytree *tree);
void splaytree_replace(struct splaytree_node *old, struct splaytree_node *new,
		       struct splaytree *tree);
int splaytree_init(struct splaytree *tree, splaytree_cmp_fn_t cmp,
		   unsigned long flags);

#endif				/* _LIBTREE_H */