add rbtree support (needed for ubi)
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Sascha Hauer
parent
b332d8565d
commit
a33bc77bdd
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@ -0,0 +1,160 @@
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/*
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Red Black Trees
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(C) 1999 Andrea Arcangeli <andrea@suse.de>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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linux/include/linux/rbtree.h
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To use rbtrees you'll have to implement your own insert and search cores.
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This will avoid us to use callbacks and to drop drammatically performances.
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I know it's not the cleaner way, but in C (not in C++) to get
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performances and genericity...
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Some example of insert and search follows here. The search is a plain
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normal search over an ordered tree. The insert instead must be implemented
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int two steps: as first thing the code must insert the element in
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order as a red leaf in the tree, then the support library function
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rb_insert_color() must be called. Such function will do the
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not trivial work to rebalance the rbtree if necessary.
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-----------------------------------------------------------------------
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static inline struct page * rb_search_page_cache(struct inode * inode,
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unsigned long offset)
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{
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struct rb_node * n = inode->i_rb_page_cache.rb_node;
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struct page * page;
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while (n)
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{
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page = rb_entry(n, struct page, rb_page_cache);
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if (offset < page->offset)
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n = n->rb_left;
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else if (offset > page->offset)
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n = n->rb_right;
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else
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return page;
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}
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return NULL;
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}
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static inline struct page * __rb_insert_page_cache(struct inode * inode,
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unsigned long offset,
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struct rb_node * node)
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{
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struct rb_node ** p = &inode->i_rb_page_cache.rb_node;
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struct rb_node * parent = NULL;
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struct page * page;
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while (*p)
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{
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parent = *p;
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page = rb_entry(parent, struct page, rb_page_cache);
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if (offset < page->offset)
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p = &(*p)->rb_left;
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else if (offset > page->offset)
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p = &(*p)->rb_right;
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else
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return page;
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}
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rb_link_node(node, parent, p);
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return NULL;
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}
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static inline struct page * rb_insert_page_cache(struct inode * inode,
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unsigned long offset,
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struct rb_node * node)
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{
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struct page * ret;
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if ((ret = __rb_insert_page_cache(inode, offset, node)))
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goto out;
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rb_insert_color(node, &inode->i_rb_page_cache);
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out:
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return ret;
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}
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-----------------------------------------------------------------------
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*/
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#ifndef _LINUX_RBTREE_H
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#define _LINUX_RBTREE_H
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#include <linux/stddef.h>
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struct rb_node
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{
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unsigned long rb_parent_color;
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#define RB_RED 0
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#define RB_BLACK 1
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struct rb_node *rb_right;
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struct rb_node *rb_left;
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} __attribute__((aligned(sizeof(long))));
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/* The alignment might seem pointless, but allegedly CRIS needs it */
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struct rb_root
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{
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struct rb_node *rb_node;
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};
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#define rb_parent(r) ((struct rb_node *)((r)->rb_parent_color & ~3))
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#define rb_color(r) ((r)->rb_parent_color & 1)
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#define rb_is_red(r) (!rb_color(r))
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#define rb_is_black(r) rb_color(r)
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#define rb_set_red(r) do { (r)->rb_parent_color &= ~1; } while (0)
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#define rb_set_black(r) do { (r)->rb_parent_color |= 1; } while (0)
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static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
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{
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rb->rb_parent_color = (rb->rb_parent_color & 3) | (unsigned long)p;
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}
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static inline void rb_set_color(struct rb_node *rb, int color)
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{
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rb->rb_parent_color = (rb->rb_parent_color & ~1) | color;
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}
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#define RB_ROOT (struct rb_root) { NULL, }
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#define rb_entry(ptr, type, member) container_of(ptr, type, member)
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#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL)
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#define RB_EMPTY_NODE(node) (rb_parent(node) == node)
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#define RB_CLEAR_NODE(node) (rb_set_parent(node, node))
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extern void rb_insert_color(struct rb_node *, struct rb_root *);
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extern void rb_erase(struct rb_node *, struct rb_root *);
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/* Find logical next and previous nodes in a tree */
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extern struct rb_node *rb_next(struct rb_node *);
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extern struct rb_node *rb_prev(struct rb_node *);
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extern struct rb_node *rb_first(struct rb_root *);
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extern struct rb_node *rb_last(struct rb_root *);
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/* Fast replacement of a single node without remove/rebalance/add/rebalance */
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extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
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struct rb_root *root);
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static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
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struct rb_node ** rb_link)
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{
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node->rb_parent_color = (unsigned long )parent;
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node->rb_left = node->rb_right = NULL;
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*rb_link = node;
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}
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#endif /* _LINUX_RBTREE_H */
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@ -1,4 +1,5 @@
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obj-y += ctype.o
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obj-y += rbtree.o
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obj-y += display_options.o
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obj-y += ldiv.o
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obj-y += string.o
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@ -0,0 +1,389 @@
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/*
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Red Black Trees
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(C) 1999 Andrea Arcangeli <andrea@suse.de>
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(C) 2002 David Woodhouse <dwmw2@infradead.org>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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linux/lib/rbtree.c
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*/
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#include <linux/rbtree.h>
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static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)
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{
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struct rb_node *right = node->rb_right;
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struct rb_node *parent = rb_parent(node);
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if ((node->rb_right = right->rb_left))
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rb_set_parent(right->rb_left, node);
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right->rb_left = node;
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rb_set_parent(right, parent);
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if (parent)
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{
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if (node == parent->rb_left)
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parent->rb_left = right;
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else
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parent->rb_right = right;
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}
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else
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root->rb_node = right;
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rb_set_parent(node, right);
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}
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static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
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{
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struct rb_node *left = node->rb_left;
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struct rb_node *parent = rb_parent(node);
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if ((node->rb_left = left->rb_right))
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rb_set_parent(left->rb_right, node);
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left->rb_right = node;
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rb_set_parent(left, parent);
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if (parent)
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{
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if (node == parent->rb_right)
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parent->rb_right = left;
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else
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parent->rb_left = left;
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}
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else
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root->rb_node = left;
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rb_set_parent(node, left);
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}
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void rb_insert_color(struct rb_node *node, struct rb_root *root)
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{
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struct rb_node *parent, *gparent;
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while ((parent = rb_parent(node)) && rb_is_red(parent))
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{
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gparent = rb_parent(parent);
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if (parent == gparent->rb_left)
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{
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{
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register struct rb_node *uncle = gparent->rb_right;
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if (uncle && rb_is_red(uncle))
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{
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rb_set_black(uncle);
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rb_set_black(parent);
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rb_set_red(gparent);
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node = gparent;
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continue;
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}
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}
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if (parent->rb_right == node)
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{
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register struct rb_node *tmp;
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__rb_rotate_left(parent, root);
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tmp = parent;
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parent = node;
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node = tmp;
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}
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rb_set_black(parent);
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rb_set_red(gparent);
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__rb_rotate_right(gparent, root);
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} else {
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{
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register struct rb_node *uncle = gparent->rb_left;
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if (uncle && rb_is_red(uncle))
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{
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rb_set_black(uncle);
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rb_set_black(parent);
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rb_set_red(gparent);
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node = gparent;
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continue;
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}
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}
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if (parent->rb_left == node)
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{
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register struct rb_node *tmp;
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__rb_rotate_right(parent, root);
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tmp = parent;
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parent = node;
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node = tmp;
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}
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rb_set_black(parent);
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rb_set_red(gparent);
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__rb_rotate_left(gparent, root);
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}
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}
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rb_set_black(root->rb_node);
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}
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static void __rb_erase_color(struct rb_node *node, struct rb_node *parent,
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struct rb_root *root)
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{
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struct rb_node *other;
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while ((!node || rb_is_black(node)) && node != root->rb_node)
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{
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if (parent->rb_left == node)
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{
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other = parent->rb_right;
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if (rb_is_red(other))
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{
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rb_set_black(other);
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rb_set_red(parent);
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__rb_rotate_left(parent, root);
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other = parent->rb_right;
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}
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if ((!other->rb_left || rb_is_black(other->rb_left)) &&
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(!other->rb_right || rb_is_black(other->rb_right)))
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{
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rb_set_red(other);
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node = parent;
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parent = rb_parent(node);
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}
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else
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{
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if (!other->rb_right || rb_is_black(other->rb_right))
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{
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struct rb_node *o_left;
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if ((o_left = other->rb_left))
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rb_set_black(o_left);
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rb_set_red(other);
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__rb_rotate_right(other, root);
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other = parent->rb_right;
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}
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rb_set_color(other, rb_color(parent));
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rb_set_black(parent);
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if (other->rb_right)
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rb_set_black(other->rb_right);
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__rb_rotate_left(parent, root);
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node = root->rb_node;
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break;
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}
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}
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else
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{
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other = parent->rb_left;
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if (rb_is_red(other))
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{
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rb_set_black(other);
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rb_set_red(parent);
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__rb_rotate_right(parent, root);
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other = parent->rb_left;
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}
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if ((!other->rb_left || rb_is_black(other->rb_left)) &&
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(!other->rb_right || rb_is_black(other->rb_right)))
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{
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rb_set_red(other);
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node = parent;
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parent = rb_parent(node);
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}
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else
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{
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if (!other->rb_left || rb_is_black(other->rb_left))
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{
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register struct rb_node *o_right;
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if ((o_right = other->rb_right))
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rb_set_black(o_right);
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rb_set_red(other);
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__rb_rotate_left(other, root);
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other = parent->rb_left;
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}
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rb_set_color(other, rb_color(parent));
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rb_set_black(parent);
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if (other->rb_left)
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rb_set_black(other->rb_left);
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__rb_rotate_right(parent, root);
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node = root->rb_node;
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break;
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}
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}
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}
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if (node)
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rb_set_black(node);
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}
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void rb_erase(struct rb_node *node, struct rb_root *root)
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{
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struct rb_node *child, *parent;
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int color;
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if (!node->rb_left)
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child = node->rb_right;
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else if (!node->rb_right)
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child = node->rb_left;
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else
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{
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struct rb_node *old = node, *left;
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node = node->rb_right;
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while ((left = node->rb_left) != NULL)
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node = left;
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child = node->rb_right;
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parent = rb_parent(node);
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color = rb_color(node);
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if (child)
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rb_set_parent(child, parent);
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if (parent == old) {
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parent->rb_right = child;
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parent = node;
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} else
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parent->rb_left = child;
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node->rb_parent_color = old->rb_parent_color;
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node->rb_right = old->rb_right;
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node->rb_left = old->rb_left;
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if (rb_parent(old))
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{
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if (rb_parent(old)->rb_left == old)
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rb_parent(old)->rb_left = node;
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else
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rb_parent(old)->rb_right = node;
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} else
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root->rb_node = node;
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rb_set_parent(old->rb_left, node);
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if (old->rb_right)
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rb_set_parent(old->rb_right, node);
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goto color;
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}
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parent = rb_parent(node);
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color = rb_color(node);
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if (child)
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rb_set_parent(child, parent);
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if (parent)
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{
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if (parent->rb_left == node)
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parent->rb_left = child;
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else
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parent->rb_right = child;
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}
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else
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root->rb_node = child;
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color:
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if (color == RB_BLACK)
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__rb_erase_color(child, parent, root);
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}
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/*
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* This function returns the first node (in sort order) of the tree.
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*/
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struct rb_node *rb_first(struct rb_root *root)
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{
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struct rb_node *n;
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n = root->rb_node;
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if (!n)
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return NULL;
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while (n->rb_left)
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n = n->rb_left;
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return n;
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}
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struct rb_node *rb_last(struct rb_root *root)
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{
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struct rb_node *n;
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n = root->rb_node;
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if (!n)
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return NULL;
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while (n->rb_right)
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n = n->rb_right;
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return n;
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}
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struct rb_node *rb_next(struct rb_node *node)
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{
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struct rb_node *parent;
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if (rb_parent(node) == node)
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return NULL;
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/* If we have a right-hand child, go down and then left as far
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as we can. */
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if (node->rb_right) {
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node = node->rb_right;
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while (node->rb_left)
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node=node->rb_left;
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return node;
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}
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/* No right-hand children. Everything down and left is
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smaller than us, so any 'next' node must be in the general
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direction of our parent. Go up the tree; any time the
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ancestor is a right-hand child of its parent, keep going
|
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up. First time it's a left-hand child of its parent, said
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parent is our 'next' node. */
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while ((parent = rb_parent(node)) && node == parent->rb_right)
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node = parent;
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|
||||
return parent;
|
||||
}
|
||||
|
||||
struct rb_node *rb_prev(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 far
|
||||
as we can. */
|
||||
if (node->rb_left) {
|
||||
node = node->rb_left;
|
||||
while (node->rb_right)
|
||||
node=node->rb_right;
|
||||
return node;
|
||||
}
|
||||
|
||||
/* No left-hand children. Go up till we find an ancestor which
|
||||
is 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;
|
||||
else
|
||||
parent->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;
|
||||
}
|
||||
Loading…
Reference in New Issue