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https://github.com/u-boot/u-boot.git
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lib, rbtree: resync with Linux-3.14
resync with linux:
commit 455c6fdbd219161bd09b1165f11699d6d73de11c
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sun Mar 30 20:40:15 2014 -0700
Linux 3.14
Needed for the MTD/UBI/UBIFS resync
Just copied the files from Linux, changed the license file header,
and add in the c-file:
+#define __UBOOT__
#include <linux/rbtree_augmented.h>
+#ifndef __UBOOT__
#include <linux/export.h>
+#else
+#include <ubi_uboot.h>
+#endif
so, it compiles for U-Boot.
Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Marek Vasut <marex@denx.de>
Cc: Sergey Lapin <slapin@ossfans.org>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Tom Rini <trini@ti.com>
This commit is contained in:
Heiko Schocher
Tom Rini
parent
7bee1c91a9
commit
9dd228b5e7
3 changed files with 724 additions and 379 deletions
736
lib/rbtree.c
736
lib/rbtree.c
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@ -2,283 +2,412 @@
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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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(C) 2012 Michel Lespinasse <walken@google.com>
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* SPDX-License-Identifier: GPL-2.0+
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linux/lib/rbtree.c
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*/
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#define __UBOOT__
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#include <linux/rbtree_augmented.h>
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#ifndef __UBOOT__
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#include <linux/export.h>
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#else
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#include <ubi_uboot.h>
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#include <linux/rbtree.h>
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#endif
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/*
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* red-black trees properties: http://en.wikipedia.org/wiki/Rbtree
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*
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* 1) A node is either red or black
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* 2) The root is black
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* 3) All leaves (NULL) are black
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* 4) Both children of every red node are black
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* 5) Every simple path from root to leaves contains the same number
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* of black nodes.
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*
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* 4 and 5 give the O(log n) guarantee, since 4 implies you cannot have two
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* consecutive red nodes in a path and every red node is therefore followed by
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* a black. So if B is the number of black nodes on every simple path (as per
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* 5), then the longest possible path due to 4 is 2B.
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*
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* We shall indicate color with case, where black nodes are uppercase and red
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* nodes will be lowercase. Unknown color nodes shall be drawn as red within
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* parentheses and have some accompanying text comment.
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*/
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static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)
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static inline void rb_set_black(struct rb_node *rb)
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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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rb->__rb_parent_color |= RB_BLACK;
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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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static inline struct rb_node *rb_red_parent(struct rb_node *red)
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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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return (struct rb_node *)red->__rb_parent_color;
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}
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/*
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* Helper function for rotations:
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* - old's parent and color get assigned to new
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* - old gets assigned new as a parent and 'color' as a color.
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*/
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static inline void
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__rb_rotate_set_parents(struct rb_node *old, struct rb_node *new,
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struct rb_root *root, int color)
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{
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struct rb_node *parent = rb_parent(old);
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new->__rb_parent_color = old->__rb_parent_color;
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rb_set_parent_color(old, new, color);
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__rb_change_child(old, new, parent, root);
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}
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static __always_inline void
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__rb_insert(struct rb_node *node, struct rb_root *root,
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void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
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{
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struct rb_node *parent = rb_red_parent(node), *gparent, *tmp;
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while (true) {
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/*
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* Loop invariant: node is red
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*
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* If there is a black parent, we are done.
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* Otherwise, take some corrective action as we don't
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* want a red root or two consecutive red nodes.
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*/
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if (!parent) {
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rb_set_parent_color(node, NULL, RB_BLACK);
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break;
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} else if (rb_is_black(parent))
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break;
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gparent = rb_red_parent(parent);
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tmp = gparent->rb_right;
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if (parent != tmp) { /* parent == gparent->rb_left */
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if (tmp && rb_is_red(tmp)) {
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/*
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* Case 1 - color flips
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*
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* G g
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* / \ / \
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* p u --> P U
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* / /
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* n N
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*
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* However, since g's parent might be red, and
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* 4) does not allow this, we need to recurse
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* at g.
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*/
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rb_set_parent_color(tmp, gparent, RB_BLACK);
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rb_set_parent_color(parent, gparent, RB_BLACK);
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node = gparent;
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parent = rb_parent(node);
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rb_set_parent_color(node, parent, RB_RED);
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continue;
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}
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tmp = parent->rb_right;
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if (node == tmp) {
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/*
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* Case 2 - left rotate at parent
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*
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* G G
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* / \ / \
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* p U --> n U
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* \ /
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* n p
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*
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* This still leaves us in violation of 4), the
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* continuation into Case 3 will fix that.
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*/
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parent->rb_right = tmp = node->rb_left;
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node->rb_left = parent;
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if (tmp)
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rb_set_parent_color(tmp, parent,
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RB_BLACK);
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rb_set_parent_color(parent, node, RB_RED);
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augment_rotate(parent, node);
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parent = node;
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tmp = node->rb_right;
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}
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/*
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* Case 3 - right rotate at gparent
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*
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* G P
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* / \ / \
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* p U --> n g
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* / \
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* n U
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*/
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gparent->rb_left = tmp; /* == parent->rb_right */
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parent->rb_right = gparent;
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if (tmp)
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rb_set_parent_color(tmp, gparent, RB_BLACK);
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__rb_rotate_set_parents(gparent, parent, root, RB_RED);
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augment_rotate(gparent, parent);
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break;
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} else {
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tmp = gparent->rb_left;
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if (tmp && rb_is_red(tmp)) {
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/* Case 1 - color flips */
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rb_set_parent_color(tmp, gparent, RB_BLACK);
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rb_set_parent_color(parent, gparent, RB_BLACK);
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node = gparent;
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parent = rb_parent(node);
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rb_set_parent_color(node, parent, RB_RED);
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continue;
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}
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tmp = parent->rb_left;
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if (node == tmp) {
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/* Case 2 - right rotate at parent */
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parent->rb_left = tmp = node->rb_right;
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node->rb_right = parent;
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if (tmp)
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rb_set_parent_color(tmp, parent,
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RB_BLACK);
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rb_set_parent_color(parent, node, RB_RED);
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augment_rotate(parent, node);
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parent = node;
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tmp = node->rb_left;
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}
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/* Case 3 - left rotate at gparent */
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gparent->rb_right = tmp; /* == parent->rb_left */
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parent->rb_left = gparent;
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if (tmp)
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rb_set_parent_color(tmp, gparent, RB_BLACK);
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__rb_rotate_set_parents(gparent, parent, root, RB_RED);
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augment_rotate(gparent, parent);
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break;
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}
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}
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}
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/*
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* Inline version for rb_erase() use - we want to be able to inline
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* and eliminate the dummy_rotate callback there
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*/
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static __always_inline void
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____rb_erase_color(struct rb_node *parent, struct rb_root *root,
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void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
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{
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struct rb_node *node = NULL, *sibling, *tmp1, *tmp2;
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while (true) {
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/*
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* Loop invariants:
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* - node is black (or NULL on first iteration)
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* - node is not the root (parent is not NULL)
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* - All leaf paths going through parent and node have a
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* black node count that is 1 lower than other leaf paths.
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*/
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sibling = parent->rb_right;
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if (node != sibling) { /* node == parent->rb_left */
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if (rb_is_red(sibling)) {
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/*
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* Case 1 - left rotate at parent
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*
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* P S
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* / \ / \
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* N s --> p Sr
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* / \ / \
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* Sl Sr N Sl
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*/
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parent->rb_right = tmp1 = sibling->rb_left;
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sibling->rb_left = parent;
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rb_set_parent_color(tmp1, parent, RB_BLACK);
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__rb_rotate_set_parents(parent, sibling, root,
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RB_RED);
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augment_rotate(parent, sibling);
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sibling = tmp1;
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}
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tmp1 = sibling->rb_right;
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if (!tmp1 || rb_is_black(tmp1)) {
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tmp2 = sibling->rb_left;
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if (!tmp2 || rb_is_black(tmp2)) {
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/*
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* Case 2 - sibling color flip
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* (p could be either color here)
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*
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* (p) (p)
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* / \ / \
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* N S --> N s
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* / \ / \
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* Sl Sr Sl Sr
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*
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* This leaves us violating 5) which
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* can be fixed by flipping p to black
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* if it was red, or by recursing at p.
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* p is red when coming from Case 1.
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*/
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rb_set_parent_color(sibling, parent,
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RB_RED);
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if (rb_is_red(parent))
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rb_set_black(parent);
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else {
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node = parent;
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parent = rb_parent(node);
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if (parent)
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continue;
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}
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break;
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}
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/*
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* Case 3 - right rotate at sibling
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* (p could be either color here)
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*
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* (p) (p)
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* / \ / \
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* N S --> N Sl
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* / \ \
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* sl Sr s
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* \
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* Sr
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*/
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sibling->rb_left = tmp1 = tmp2->rb_right;
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tmp2->rb_right = sibling;
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parent->rb_right = tmp2;
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if (tmp1)
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rb_set_parent_color(tmp1, sibling,
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RB_BLACK);
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augment_rotate(sibling, tmp2);
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tmp1 = sibling;
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sibling = tmp2;
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}
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/*
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* Case 4 - left rotate at parent + color flips
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* (p and sl could be either color here.
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* After rotation, p becomes black, s acquires
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* p's color, and sl keeps its color)
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*
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* (p) (s)
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* / \ / \
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* N S --> P Sr
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* / \ / \
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* (sl) sr N (sl)
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*/
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parent->rb_right = tmp2 = sibling->rb_left;
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sibling->rb_left = parent;
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rb_set_parent_color(tmp1, sibling, RB_BLACK);
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if (tmp2)
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rb_set_parent(tmp2, parent);
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__rb_rotate_set_parents(parent, sibling, root,
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RB_BLACK);
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augment_rotate(parent, sibling);
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break;
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} else {
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sibling = parent->rb_left;
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if (rb_is_red(sibling)) {
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/* Case 1 - right rotate at parent */
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parent->rb_left = tmp1 = sibling->rb_right;
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sibling->rb_right = parent;
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rb_set_parent_color(tmp1, parent, RB_BLACK);
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__rb_rotate_set_parents(parent, sibling, root,
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RB_RED);
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augment_rotate(parent, sibling);
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sibling = tmp1;
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}
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tmp1 = sibling->rb_left;
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if (!tmp1 || rb_is_black(tmp1)) {
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tmp2 = sibling->rb_right;
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if (!tmp2 || rb_is_black(tmp2)) {
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/* Case 2 - sibling color flip */
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rb_set_parent_color(sibling, parent,
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RB_RED);
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if (rb_is_red(parent))
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rb_set_black(parent);
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else {
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node = parent;
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parent = rb_parent(node);
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if (parent)
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continue;
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}
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break;
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}
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/* Case 3 - right rotate at sibling */
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sibling->rb_right = tmp1 = tmp2->rb_left;
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tmp2->rb_left = sibling;
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parent->rb_left = tmp2;
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if (tmp1)
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rb_set_parent_color(tmp1, sibling,
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RB_BLACK);
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augment_rotate(sibling, tmp2);
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tmp1 = sibling;
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sibling = tmp2;
|
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}
|
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/* Case 4 - left rotate at parent + color flips */
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parent->rb_left = tmp2 = sibling->rb_right;
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sibling->rb_right = parent;
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rb_set_parent_color(tmp1, sibling, RB_BLACK);
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if (tmp2)
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rb_set_parent(tmp2, parent);
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__rb_rotate_set_parents(parent, sibling, root,
|
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RB_BLACK);
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augment_rotate(parent, sibling);
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break;
|
||||
}
|
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}
|
||||
}
|
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|
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/* Non-inline version for rb_erase_augmented() use */
|
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void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
|
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void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
|
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{
|
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____rb_erase_color(parent, root, augment_rotate);
|
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}
|
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EXPORT_SYMBOL(__rb_erase_color);
|
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|
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/*
|
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* Non-augmented rbtree manipulation functions.
|
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*
|
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* We use dummy augmented callbacks here, and have the compiler optimize them
|
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* out of the rb_insert_color() and rb_erase() function definitions.
|
||||
*/
|
||||
|
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static inline void dummy_propagate(struct rb_node *node, struct rb_node *stop) {}
|
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static inline void dummy_copy(struct rb_node *old, struct rb_node *new) {}
|
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static inline void dummy_rotate(struct rb_node *old, struct rb_node *new) {}
|
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|
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static const struct rb_augment_callbacks dummy_callbacks = {
|
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dummy_propagate, dummy_copy, dummy_rotate
|
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};
|
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|
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void rb_insert_color(struct rb_node *node, struct rb_root *root)
|
||||
{
|
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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;
|
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if (uncle && rb_is_red(uncle))
|
||||
{
|
||||
rb_set_black(uncle);
|
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rb_set_black(parent);
|
||||
rb_set_red(gparent);
|
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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))
|
||||
{
|
||||
struct rb_node *o_left;
|
||||
if ((o_left = other->rb_left))
|
||||
rb_set_black(o_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);
|
||||
if (other->rb_right)
|
||||
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))
|
||||
{
|
||||
register struct rb_node *o_right;
|
||||
if ((o_right = other->rb_right))
|
||||
rb_set_black(o_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);
|
||||
if (other->rb_left)
|
||||
rb_set_black(other->rb_left);
|
||||
__rb_rotate_right(parent, root);
|
||||
node = root->rb_node;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
if (node)
|
||||
rb_set_black(node);
|
||||
__rb_insert(node, root, dummy_rotate);
|
||||
}
|
||||
EXPORT_SYMBOL(rb_insert_color);
|
||||
|
||||
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;
|
||||
child = node->rb_right;
|
||||
parent = rb_parent(node);
|
||||
color = rb_color(node);
|
||||
|
||||
if (child)
|
||||
rb_set_parent(child, parent);
|
||||
if (parent == old) {
|
||||
parent->rb_right = child;
|
||||
parent = node;
|
||||
} else
|
||||
parent->rb_left = child;
|
||||
|
||||
node->rb_parent_color = old->rb_parent_color;
|
||||
node->rb_right = old->rb_right;
|
||||
node->rb_left = old->rb_left;
|
||||
|
||||
if (rb_parent(old))
|
||||
{
|
||||
if (rb_parent(old)->rb_left == old)
|
||||
rb_parent(old)->rb_left = node;
|
||||
else
|
||||
rb_parent(old)->rb_right = node;
|
||||
} else
|
||||
root->rb_node = node;
|
||||
|
||||
rb_set_parent(old->rb_left, node);
|
||||
if (old->rb_right)
|
||||
rb_set_parent(old->rb_right, 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;
|
||||
else
|
||||
parent->rb_right = child;
|
||||
}
|
||||
else
|
||||
root->rb_node = child;
|
||||
|
||||
color:
|
||||
if (color == RB_BLACK)
|
||||
__rb_erase_color(child, parent, root);
|
||||
struct rb_node *rebalance;
|
||||
rebalance = __rb_erase_augmented(node, root, &dummy_callbacks);
|
||||
if (rebalance)
|
||||
____rb_erase_color(rebalance, root, dummy_rotate);
|
||||
}
|
||||
EXPORT_SYMBOL(rb_erase);
|
||||
|
||||
/*
|
||||
* Augmented rbtree manipulation functions.
|
||||
*
|
||||
* This instantiates the same __always_inline functions as in the non-augmented
|
||||
* case, but this time with user-defined callbacks.
|
||||
*/
|
||||
|
||||
void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
|
||||
void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
|
||||
{
|
||||
__rb_insert(node, root, augment_rotate);
|
||||
}
|
||||
EXPORT_SYMBOL(__rb_insert_augmented);
|
||||
|
||||
/*
|
||||
* This function returns the first node (in sort order) of the tree.
|
||||
*/
|
||||
struct rb_node *rb_first(struct rb_root *root)
|
||||
struct rb_node *rb_first(const struct rb_root *root)
|
||||
{
|
||||
struct rb_node *n;
|
||||
|
||||
|
|
@ -289,8 +418,9 @@ struct rb_node *rb_first(struct rb_root *root)
|
|||
n = n->rb_left;
|
||||
return n;
|
||||
}
|
||||
EXPORT_SYMBOL(rb_first);
|
||||
|
||||
struct rb_node *rb_last(struct rb_root *root)
|
||||
struct rb_node *rb_last(const struct rb_root *root)
|
||||
{
|
||||
struct rb_node *n;
|
||||
|
||||
|
|
@ -301,58 +431,68 @@ struct rb_node *rb_last(struct rb_root *root)
|
|||
n = n->rb_right;
|
||||
return n;
|
||||
}
|
||||
EXPORT_SYMBOL(rb_last);
|
||||
|
||||
struct rb_node *rb_next(struct rb_node *node)
|
||||
struct rb_node *rb_next(const struct rb_node *node)
|
||||
{
|
||||
struct rb_node *parent;
|
||||
|
||||
if (rb_parent(node) == node)
|
||||
if (RB_EMPTY_NODE(node))
|
||||
return NULL;
|
||||
|
||||
/* If we have a right-hand child, go down and then left as far
|
||||
as we can. */
|
||||
/*
|
||||
* If we have a right-hand child, go down and then left as far
|
||||
* as we can.
|
||||
*/
|
||||
if (node->rb_right) {
|
||||
node = node->rb_right;
|
||||
node = node->rb_right;
|
||||
while (node->rb_left)
|
||||
node=node->rb_left;
|
||||
return node;
|
||||
return (struct rb_node *)node;
|
||||
}
|
||||
|
||||
/* No right-hand children. Everything down and left is
|
||||
smaller than us, so any 'next' node must be in the general
|
||||
direction of our parent. Go up the tree; any time the
|
||||
ancestor is a right-hand child of its parent, keep going
|
||||
up. First time it's a left-hand child of its parent, said
|
||||
parent is our 'next' node. */
|
||||
/*
|
||||
* No right-hand children. Everything down and left is smaller than us,
|
||||
* so any 'next' node must be in the general direction of our parent.
|
||||
* Go up the tree; any time the ancestor is a right-hand child of its
|
||||
* parent, keep going up. First time it's a left-hand child of its
|
||||
* parent, said parent is our 'next' node.
|
||||
*/
|
||||
while ((parent = rb_parent(node)) && node == parent->rb_right)
|
||||
node = parent;
|
||||
|
||||
return parent;
|
||||
}
|
||||
EXPORT_SYMBOL(rb_next);
|
||||
|
||||
struct rb_node *rb_prev(struct rb_node *node)
|
||||
struct rb_node *rb_prev(const struct rb_node *node)
|
||||
{
|
||||
struct rb_node *parent;
|
||||
|
||||
if (rb_parent(node) == node)
|
||||
if (RB_EMPTY_NODE(node))
|
||||
return NULL;
|
||||
|
||||
/* If we have a left-hand child, go down and then right as far
|
||||
as we can. */
|
||||
/*
|
||||
* 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;
|
||||
node = node->rb_left;
|
||||
while (node->rb_right)
|
||||
node=node->rb_right;
|
||||
return node;
|
||||
return (struct rb_node *)node;
|
||||
}
|
||||
|
||||
/* No left-hand children. Go up till we find an ancestor which
|
||||
is a right-hand child of its parent */
|
||||
/*
|
||||
* 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;
|
||||
}
|
||||
EXPORT_SYMBOL(rb_prev);
|
||||
|
||||
void rb_replace_node(struct rb_node *victim, struct rb_node *new,
|
||||
struct rb_root *root)
|
||||
|
|
@ -360,14 +500,7 @@ void rb_replace_node(struct rb_node *victim, struct rb_node *new,
|
|||
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;
|
||||
}
|
||||
__rb_change_child(victim, new, parent, root);
|
||||
if (victim->rb_left)
|
||||
rb_set_parent(victim->rb_left, new);
|
||||
if (victim->rb_right)
|
||||
|
|
@ -376,3 +509,44 @@ void rb_replace_node(struct rb_node *victim, struct rb_node *new,
|
|||
/* Copy the pointers/colour from the victim to the replacement */
|
||||
*new = *victim;
|
||||
}
|
||||
EXPORT_SYMBOL(rb_replace_node);
|
||||
|
||||
static struct rb_node *rb_left_deepest_node(const struct rb_node *node)
|
||||
{
|
||||
for (;;) {
|
||||
if (node->rb_left)
|
||||
node = node->rb_left;
|
||||
else if (node->rb_right)
|
||||
node = node->rb_right;
|
||||
else
|
||||
return (struct rb_node *)node;
|
||||
}
|
||||
}
|
||||
|
||||
struct rb_node *rb_next_postorder(const struct rb_node *node)
|
||||
{
|
||||
const struct rb_node *parent;
|
||||
if (!node)
|
||||
return NULL;
|
||||
parent = rb_parent(node);
|
||||
|
||||
/* If we're sitting on node, we've already seen our children */
|
||||
if (parent && node == parent->rb_left && parent->rb_right) {
|
||||
/* If we are the parent's left node, go to the parent's right
|
||||
* node then all the way down to the left */
|
||||
return rb_left_deepest_node(parent->rb_right);
|
||||
} else
|
||||
/* Otherwise we are the parent's right node, and the parent
|
||||
* should be next */
|
||||
return (struct rb_node *)parent;
|
||||
}
|
||||
EXPORT_SYMBOL(rb_next_postorder);
|
||||
|
||||
struct rb_node *rb_first_postorder(const struct rb_root *root)
|
||||
{
|
||||
if (!root->rb_node)
|
||||
return NULL;
|
||||
|
||||
return rb_left_deepest_node(root->rb_node);
|
||||
}
|
||||
EXPORT_SYMBOL(rb_first_postorder);
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue