/*Red Black Trees(C) 1999  Andrea Arcangeli <andrea@suse.de>This program is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 2 of the License, or(at your option) any later version.This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See theGNU General Public License for more details.You should have received a copy of the GNU General Public Licensealong with this program; if not, write to the Free SoftwareFoundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USAlinux/include/linux/rbtree.hTo use rbtrees you'll have to implement your own insert and search cores.This will avoid us to use callbacks and to drop drammatically performances.I know it's not the cleaner way,  but in C (not in C++) to getperformances and genericity...Some example of insert and search follows here. The search is a plainnormal search over an ordered tree. The insert instead must be implementedin two steps: First, the code must insert the element in order as a red leafin the tree, and then the support library function rb_insert_color() mustbe called. Such function will do the not trivial work to rebalance therbtree, if necessary.-----------------------------------------------------------------------
static inline struct page * rb_search_page_cache(struct inode * inode,unsigned long offset)
{struct rb_node * n = inode->i_rb_page_cache.rb_node;struct page * page;while (n){page = rb_entry(n, struct page, rb_page_cache);if (offset < page->offset)n = n->rb_left;else if (offset > page->offset)n = n->rb_right;elsereturn page;}return NULL;
}static inline struct page * __rb_insert_page_cache(struct inode * inode,unsigned long offset,struct rb_node * node)
{struct rb_node ** p = &inode->i_rb_page_cache.rb_node;struct rb_node * parent = NULL;struct page * page;while (*p){parent = *p;page = rb_entry(parent, struct page, rb_page_cache);if (offset < page->offset)p = &(*p)->rb_left;else if (offset > page->offset)p = &(*p)->rb_right;elsereturn page;}rb_link_node(node, parent, p);return NULL;
}static inline struct page * rb_insert_page_cache(struct inode * inode,unsigned long offset,struct rb_node * node)
{struct page * ret;if ((ret = __rb_insert_page_cache(inode, offset, node)))goto out;rb_insert_color(node, &inode->i_rb_page_cache);out:return ret;
}
-----------------------------------------------------------------------
*/#ifndef    _SLINUX_RBTREE_H
#define    _SLINUX_RBTREE_H#include <stdio.h>
//#include <linux/kernel.h>
//#include <linux/stddef.h>struct rb_node
{unsigned long  rb_parent_color;
#define    RB_RED        0
#define    RB_BLACK    1struct rb_node *rb_right;struct rb_node *rb_left;
} /*  __attribute__((aligned(sizeof(long))))*/;/* The alignment might seem pointless, but allegedly CRIS needs it */struct rb_root
{struct rb_node *rb_node;
};#define rb_parent(r)   ((struct rb_node *)((r)->rb_parent_color & ~3))
#define rb_color(r)   ((r)->rb_parent_color & 1)
#define rb_is_red(r)   (!rb_color(r))
#define rb_is_black(r) rb_color(r)
#define rb_set_red(r)  do { (r)->rb_parent_color &= ~1; } while (0)
#define rb_set_black(r)  do { (r)->rb_parent_color |= 1; } while (0)static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
{rb->rb_parent_color = (rb->rb_parent_color & 3) | (unsigned long)p;
}
static inline void rb_set_color(struct rb_node *rb, int color)
{rb->rb_parent_color = (rb->rb_parent_color & ~1) | color;
}#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)#define container_of(ptr, type, member) ({          const typeof( ((type *)0)->member ) *__mptr = (ptr);    (type *)( (char *)__mptr - offsetof(type,member) );})#define RB_ROOT    (struct rb_root) { NULL, }
#define    rb_entry(ptr, type, member) container_of(ptr, type, member)#define RB_EMPTY_ROOT(root)    ((root)->rb_node == NULL)
#define RB_EMPTY_NODE(node)    (rb_parent(node) == node)
#define RB_CLEAR_NODE(node)    (rb_set_parent(node, node))static inline void rb_init_node(struct rb_node *rb)
{rb->rb_parent_color = 0;rb->rb_right = NULL;rb->rb_left = NULL;RB_CLEAR_NODE(rb);
}extern void rb_insert_color(struct rb_node *, struct rb_root *);
extern void rb_erase(struct rb_node *, struct rb_root *);typedef void (*rb_augment_f)(struct rb_node *node, void *data);extern void rb_augment_insert(struct rb_node *node,rb_augment_f func, void *data);
extern struct rb_node *rb_augment_erase_begin(struct rb_node *node);
extern void rb_augment_erase_end(struct rb_node *node,rb_augment_f func, void *data);/* Find logical next and previous nodes in a tree */
extern struct rb_node *rb_next(const struct rb_node *);
extern struct rb_node *rb_prev(const struct rb_node *);
extern struct rb_node *rb_first(const struct rb_root *);
extern struct rb_node *rb_last(const struct rb_root *);/* Fast replacement of a single node without remove/rebalance/add/rebalance */
extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,struct rb_root *root);static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,struct rb_node ** rb_link)
{node->rb_parent_color = (unsigned long )parent;node->rb_left = node->rb_right = NULL;*rb_link = node;
}#endif    /* _LINUX_RBTREE_H */

/*Red Black Trees(C) 1999  Andrea Arcangeli <andrea@suse.de>(C) 2002  David Woodhouse <dwmw2@infradead.org>This program is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 2 of the License, or(at your option) any later version.This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See theGNU General Public License for more details.You should have received a copy of the GNU General Public Licensealong with this program; if not, write to the Free SoftwareFoundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USAlinux/lib/rbtree.c
*/#include "rbtree.h"static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)
{struct rb_node *right = node->rb_right;struct rb_node *parent = rb_parent(node);if ((node->rb_right = right->rb_left))rb_set_parent(right->rb_left, node);right->rb_left = node;rb_set_parent(right, parent);if (parent){if (node == parent->rb_left)parent->rb_left = right;elseparent->rb_right = right;}elseroot->rb_node = right;rb_set_parent(node, right);
}static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
{struct rb_node *left = node->rb_left;struct rb_node *parent = rb_parent(node);if ((node->rb_left = left->rb_right))rb_set_parent(left->rb_right, node);left->rb_right = node;rb_set_parent(left, parent);if (parent){if (node == parent->rb_right)parent->rb_right = left;elseparent->rb_left = left;}elseroot->rb_node = left;rb_set_parent(node, left);
}void rb_insert_color(struct rb_node *node, struct rb_root *root)
{struct rb_node *parent, *gparent;while ((parent = rb_parent(node)) && rb_is_red(parent)){gparent = rb_parent(parent);if (parent == gparent->rb_left){{register struct rb_node *uncle = gparent->rb_right;if (uncle && rb_is_red(uncle)){rb_set_black(uncle);rb_set_black(parent);rb_set_red(gparent);node = gparent;continue;}}if (parent->rb_right == node){register struct rb_node *tmp;__rb_rotate_left(parent, root);tmp = parent;parent = node;node = tmp;}rb_set_black(parent);rb_set_red(gparent);__rb_rotate_right(gparent, root);} else {{register struct rb_node *uncle = gparent->rb_left;if (uncle && rb_is_red(uncle)){rb_set_black(uncle);rb_set_black(parent);rb_set_red(gparent);node = gparent;continue;}}if (parent->rb_left == node){register struct rb_node *tmp;__rb_rotate_right(parent, root);tmp = parent;parent = node;node = tmp;}rb_set_black(parent);rb_set_red(gparent);__rb_rotate_left(gparent, root);}}rb_set_black(root->rb_node);
}static void __rb_erase_color(struct rb_node *node, struct rb_node *parent,struct rb_root *root)
{struct rb_node *other;while ((!node || rb_is_black(node)) && node != root->rb_node){if (parent->rb_left == node){other = parent->rb_right;if (rb_is_red(other)){rb_set_black(other);rb_set_red(parent);__rb_rotate_left(parent, root);other = parent->rb_right;}if ((!other->rb_left || rb_is_black(other->rb_left)) &&(!other->rb_right || rb_is_black(other->rb_right))){rb_set_red(other);node = parent;parent = rb_parent(node);}else{if (!other->rb_right || rb_is_black(other->rb_right)){rb_set_black(other->rb_left);rb_set_red(other);__rb_rotate_right(other, root);other = parent->rb_right;}rb_set_color(other, rb_color(parent));rb_set_black(parent);rb_set_black(other->rb_right);__rb_rotate_left(parent, root);node = root->rb_node;break;}}else{other = parent->rb_left;if (rb_is_red(other)){rb_set_black(other);rb_set_red(parent);__rb_rotate_right(parent, root);other = parent->rb_left;}if ((!other->rb_left || rb_is_black(other->rb_left)) &&(!other->rb_right || rb_is_black(other->rb_right))){rb_set_red(other);node = parent;parent = rb_parent(node);}else{if (!other->rb_left || rb_is_black(other->rb_left)){rb_set_black(other->rb_right);rb_set_red(other);__rb_rotate_left(other, root);other = parent->rb_left;}rb_set_color(other, rb_color(parent));rb_set_black(parent);rb_set_black(other->rb_left);__rb_rotate_right(parent, root);node = root->rb_node;break;}}}if (node)rb_set_black(node);
}void rb_erase(struct rb_node *node, struct rb_root *root)
{struct rb_node *child, *parent;int color;if (!node->rb_left)child = node->rb_right;else if (!node->rb_right)child = node->rb_left;else{struct rb_node *old = node, *left;node = node->rb_right;while ((left = node->rb_left) != NULL)node = left;if (rb_parent(old)) {if (rb_parent(old)->rb_left == old)rb_parent(old)->rb_left = node;elserb_parent(old)->rb_right = node;} elseroot->rb_node = node;child = node->rb_right;parent = rb_parent(node);color = rb_color(node);if (parent == old) {parent = node;} else {if (child)rb_set_parent(child, parent);parent->rb_left = child;node->rb_right = old->rb_right;rb_set_parent(old->rb_right, node);}node->rb_parent_color = old->rb_parent_color;node->rb_left = old->rb_left;rb_set_parent(old->rb_left, node);goto color;}parent = rb_parent(node);color = rb_color(node);if (child)rb_set_parent(child, parent);if (parent){if (parent->rb_left == node)parent->rb_left = child;elseparent->rb_right = child;}elseroot->rb_node = child;color:if (color == RB_BLACK)__rb_erase_color(child, parent, root);
}static void rb_augment_path(struct rb_node *node, rb_augment_f func, void *data)
{struct rb_node *parent;up:func(node, data);parent = rb_parent(node);if (!parent)return;if (node == parent->rb_left && parent->rb_right)func(parent->rb_right, data);else if (parent->rb_left)func(parent->rb_left, data);node = parent;goto up;
}/** after inserting @node into the tree, update the tree to account for* both the new entry and any damage done by rebalance*/
void rb_augment_insert(struct rb_node *node, rb_augment_f func, void *data)
{if (node->rb_left)node = node->rb_left;else if (node->rb_right)node = node->rb_right;rb_augment_path(node, func, data);
}/** before removing the node, find the deepest node on the rebalance path* that will still be there after @node gets removed*/
struct rb_node *rb_augment_erase_begin(struct rb_node *node)
{struct rb_node *deepest;if (!node->rb_right && !node->rb_left)deepest = rb_parent(node);else if (!node->rb_right)deepest = node->rb_left;else if (!node->rb_left)deepest = node->rb_right;else {deepest = rb_next(node);if (deepest->rb_right)deepest = deepest->rb_right;else if (rb_parent(deepest) != node)deepest = rb_parent(deepest);}return deepest;
}/** after removal, update the tree to account for the removed entry* and any rebalance damage.*/
void rb_augment_erase_end(struct rb_node *node, rb_augment_f func, void *data)
{if (node)rb_augment_path(node, func, data);
}/** This function returns the first node (in sort order) of the tree.*/
struct rb_node *rb_first(const struct rb_root *root)
{struct rb_node    *n;n = root->rb_node;if (!n)return NULL;while (n->rb_left)n = n->rb_left;return n;
}struct rb_node *rb_last(const struct rb_root *root)
{struct rb_node    *n;n = root->rb_node;if (!n)return NULL;while (n->rb_right)n = n->rb_right;return n;
}struct rb_node *rb_next(const struct rb_node *node)
{struct rb_node *parent;if (rb_parent(node) == node)return NULL;/* If we have a right-hand child, go down and then left as faras we can. */if (node->rb_right) {node = node->rb_right;while (node->rb_left)node=node->rb_left;return (struct rb_node *)node;}/* No right-hand children.  Everything down and left issmaller than us, so any 'next' node must be in the generaldirection of our parent. Go up the tree; any time theancestor is a right-hand child of its parent, keep goingup. First time it's a left-hand child of its parent, saidparent is our 'next' node. */while ((parent = rb_parent(node)) && node == parent->rb_right)node = parent;return parent;
}struct rb_node *rb_prev(const struct rb_node *node)
{struct rb_node *parent;if (rb_parent(node) == node)return NULL;/* If we have a left-hand child, go down and then right as faras we can. */if (node->rb_left) {node = node->rb_left;while (node->rb_right)node=node->rb_right;return (struct rb_node *)node;}/* No left-hand children. Go up till we find an ancestor whichis a right-hand child of its parent */while ((parent = rb_parent(node)) && node == parent->rb_left)node = parent;return parent;
}void rb_replace_node(struct rb_node *victim, struct rb_node *new,struct rb_root *root)
{struct rb_node *parent = rb_parent(victim);/* Set the surrounding nodes to point to the replacement */if (parent) {if (victim == parent->rb_left)parent->rb_left = new;elseparent->rb_right = new;} else {root->rb_node = new;}if (victim->rb_left)rb_set_parent(victim->rb_left, new);if (victim->rb_right)rb_set_parent(victim->rb_right, new);/* Copy the pointers/colour from the victim to the replacement */*new = *victim;
}

/*** 根据Linux Kernel定义的红黑树(Red Black Tree)**/#include <stdio.h>
#include <stdlib.h>
#include "rbtree.h"#define CHECK_INSERT 0    // "插入"动作的检测开关(0，关闭；1，打开)
#define CHECK_DELETE 0    // "删除"动作的检测开关(0，关闭；1，打开)
#define LENGTH(a) ( (sizeof(a)) / (sizeof(a[0])) )typedef int Type;struct my_node {struct rb_node rb_node;    // 红黑树节点Type key;                // 键值// ... 用户自定义的数据
};/** 查找"红黑树"中键值为key的节点。没找到的话，返回NULL。*/
struct my_node *my_search(struct rb_root *root, Type key)
{struct rb_node *rbnode = root->rb_node;while (rbnode!=NULL){struct my_node *mynode = container_of(rbnode, struct my_node, rb_node);if (key < mynode->key)rbnode = rbnode->rb_left;else if (key > mynode->key)rbnode = rbnode->rb_right;elsereturn mynode;}return NULL;
}/** 将key插入到红黑树中。插入成功，返回0；失败返回-1。*/
int my_insert(struct rb_root *root, Type key)
{struct my_node *mynode; // 新建结点struct rb_node **tmp = &(root->rb_node), *parent = NULL;/* Figure out where to put new node */while (*tmp){struct my_node *my = container_of(*tmp, struct my_node, rb_node);parent = *tmp;if (key < my->key)tmp = &((*tmp)->rb_left);else if (key > my->key)tmp = &((*tmp)->rb_right);elsereturn -1;}// 如果新建结点失败，则返回。if ((mynode=malloc(sizeof(struct my_node))) == NULL)return -1;mynode->key = key;/* Add new node and rebalance tree. */rb_link_node(&mynode->rb_node, parent, tmp);rb_insert_color(&mynode->rb_node, root);return 0;
}/** 删除键值为key的结点*/
void my_delete(struct rb_root *root, Type key)
{struct my_node *mynode;// 在红黑树中查找key对应的节点mynodeif ((mynode = my_search(root, key)) == NULL)return ;// 从红黑树中删除节点mynoderb_erase(&mynode->rb_node, root);free(mynode);
}/** 打印"红黑树"*/
static void print_rbtree(struct rb_node *tree, Type key, int direction)
{if(tree != NULL){if(direction==0)    // tree是根节点printf("%2d(B) is rootn", key);else                // tree是分支节点printf("%2d(%s) is %2d's %6s childn", key, rb_is_black(tree)?"B":"R", key, direction==1?"right" : "left");if (tree->rb_left)print_rbtree(tree->rb_left, rb_entry(tree->rb_left, struct my_node, rb_node)->key, -1);if (tree->rb_right)print_rbtree(tree->rb_right,rb_entry(tree->rb_right, struct my_node, rb_node)->key,  1);}
}void my_print(struct rb_root *root)
{if (root!=NULL && root->rb_node!=NULL)print_rbtree(root->rb_node, rb_entry(root->rb_node, struct my_node, rb_node)->key,  0);
}void main()
{int a[] = {10, 40, 30, 60, 90, 70, 20, 50, 80};int i, ilen=LENGTH(a);struct rb_root mytree = RB_ROOT;printf("== 原始数据: ");for(i=0; i<ilen; i++)printf("%d ", a[i]);printf("n");for (i=0; i < ilen; i++){my_insert(&mytree, a[i]);
#if CHECK_INSERTprintf("== 添加节点: %dn", a[i]);printf("== 树的详细信息: n");my_print(&mytree);printf("n");
#endif}#if CHECK_DELETEfor (i=0; i<ilen; i++) {my_delete(&mytree, a[i]);printf("== 删除节点: %dn", a[i]);printf("== 树的详细信息: n");my_print(&mytree);printf("n");}
#endif
}