mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-11-18 23:54:26 +08:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
395 lines
8.9 KiB
C
395 lines
8.9 KiB
C
/*
|
|
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 modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the 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 of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
|
|
linux/lib/rbtree.c
|
|
*/
|
|
|
|
#include <linux/rbtree.h>
|
|
#include <linux/module.h>
|
|
|
|
static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)
|
|
{
|
|
struct rb_node *right = node->rb_right;
|
|
|
|
if ((node->rb_right = right->rb_left))
|
|
right->rb_left->rb_parent = node;
|
|
right->rb_left = node;
|
|
|
|
if ((right->rb_parent = node->rb_parent))
|
|
{
|
|
if (node == node->rb_parent->rb_left)
|
|
node->rb_parent->rb_left = right;
|
|
else
|
|
node->rb_parent->rb_right = right;
|
|
}
|
|
else
|
|
root->rb_node = right;
|
|
node->rb_parent = right;
|
|
}
|
|
|
|
static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
|
|
{
|
|
struct rb_node *left = node->rb_left;
|
|
|
|
if ((node->rb_left = left->rb_right))
|
|
left->rb_right->rb_parent = node;
|
|
left->rb_right = node;
|
|
|
|
if ((left->rb_parent = node->rb_parent))
|
|
{
|
|
if (node == node->rb_parent->rb_right)
|
|
node->rb_parent->rb_right = left;
|
|
else
|
|
node->rb_parent->rb_left = left;
|
|
}
|
|
else
|
|
root->rb_node = left;
|
|
node->rb_parent = left;
|
|
}
|
|
|
|
void rb_insert_color(struct rb_node *node, struct rb_root *root)
|
|
{
|
|
struct rb_node *parent, *gparent;
|
|
|
|
while ((parent = node->rb_parent) && parent->rb_color == RB_RED)
|
|
{
|
|
gparent = parent->rb_parent;
|
|
|
|
if (parent == gparent->rb_left)
|
|
{
|
|
{
|
|
register struct rb_node *uncle = gparent->rb_right;
|
|
if (uncle && uncle->rb_color == RB_RED)
|
|
{
|
|
uncle->rb_color = RB_BLACK;
|
|
parent->rb_color = RB_BLACK;
|
|
gparent->rb_color = RB_RED;
|
|
node = gparent;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
if (parent->rb_right == node)
|
|
{
|
|
register struct rb_node *tmp;
|
|
__rb_rotate_left(parent, root);
|
|
tmp = parent;
|
|
parent = node;
|
|
node = tmp;
|
|
}
|
|
|
|
parent->rb_color = RB_BLACK;
|
|
gparent->rb_color = RB_RED;
|
|
__rb_rotate_right(gparent, root);
|
|
} else {
|
|
{
|
|
register struct rb_node *uncle = gparent->rb_left;
|
|
if (uncle && uncle->rb_color == RB_RED)
|
|
{
|
|
uncle->rb_color = RB_BLACK;
|
|
parent->rb_color = RB_BLACK;
|
|
gparent->rb_color = RB_RED;
|
|
node = gparent;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
if (parent->rb_left == node)
|
|
{
|
|
register struct rb_node *tmp;
|
|
__rb_rotate_right(parent, root);
|
|
tmp = parent;
|
|
parent = node;
|
|
node = tmp;
|
|
}
|
|
|
|
parent->rb_color = RB_BLACK;
|
|
gparent->rb_color = RB_RED;
|
|
__rb_rotate_left(gparent, root);
|
|
}
|
|
}
|
|
|
|
root->rb_node->rb_color = RB_BLACK;
|
|
}
|
|
EXPORT_SYMBOL(rb_insert_color);
|
|
|
|
static void __rb_erase_color(struct rb_node *node, struct rb_node *parent,
|
|
struct rb_root *root)
|
|
{
|
|
struct rb_node *other;
|
|
|
|
while ((!node || node->rb_color == RB_BLACK) && node != root->rb_node)
|
|
{
|
|
if (parent->rb_left == node)
|
|
{
|
|
other = parent->rb_right;
|
|
if (other->rb_color == RB_RED)
|
|
{
|
|
other->rb_color = RB_BLACK;
|
|
parent->rb_color = RB_RED;
|
|
__rb_rotate_left(parent, root);
|
|
other = parent->rb_right;
|
|
}
|
|
if ((!other->rb_left ||
|
|
other->rb_left->rb_color == RB_BLACK)
|
|
&& (!other->rb_right ||
|
|
other->rb_right->rb_color == RB_BLACK))
|
|
{
|
|
other->rb_color = RB_RED;
|
|
node = parent;
|
|
parent = node->rb_parent;
|
|
}
|
|
else
|
|
{
|
|
if (!other->rb_right ||
|
|
other->rb_right->rb_color == RB_BLACK)
|
|
{
|
|
register struct rb_node *o_left;
|
|
if ((o_left = other->rb_left))
|
|
o_left->rb_color = RB_BLACK;
|
|
other->rb_color = RB_RED;
|
|
__rb_rotate_right(other, root);
|
|
other = parent->rb_right;
|
|
}
|
|
other->rb_color = parent->rb_color;
|
|
parent->rb_color = RB_BLACK;
|
|
if (other->rb_right)
|
|
other->rb_right->rb_color = RB_BLACK;
|
|
__rb_rotate_left(parent, root);
|
|
node = root->rb_node;
|
|
break;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
other = parent->rb_left;
|
|
if (other->rb_color == RB_RED)
|
|
{
|
|
other->rb_color = RB_BLACK;
|
|
parent->rb_color = RB_RED;
|
|
__rb_rotate_right(parent, root);
|
|
other = parent->rb_left;
|
|
}
|
|
if ((!other->rb_left ||
|
|
other->rb_left->rb_color == RB_BLACK)
|
|
&& (!other->rb_right ||
|
|
other->rb_right->rb_color == RB_BLACK))
|
|
{
|
|
other->rb_color = RB_RED;
|
|
node = parent;
|
|
parent = node->rb_parent;
|
|
}
|
|
else
|
|
{
|
|
if (!other->rb_left ||
|
|
other->rb_left->rb_color == RB_BLACK)
|
|
{
|
|
register struct rb_node *o_right;
|
|
if ((o_right = other->rb_right))
|
|
o_right->rb_color = RB_BLACK;
|
|
other->rb_color = RB_RED;
|
|
__rb_rotate_left(other, root);
|
|
other = parent->rb_left;
|
|
}
|
|
other->rb_color = parent->rb_color;
|
|
parent->rb_color = RB_BLACK;
|
|
if (other->rb_left)
|
|
other->rb_left->rb_color = RB_BLACK;
|
|
__rb_rotate_right(parent, root);
|
|
node = root->rb_node;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (node)
|
|
node->rb_color = RB_BLACK;
|
|
}
|
|
|
|
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 = node->rb_parent;
|
|
color = node->rb_color;
|
|
|
|
if (child)
|
|
child->rb_parent = parent;
|
|
if (parent)
|
|
{
|
|
if (parent->rb_left == node)
|
|
parent->rb_left = child;
|
|
else
|
|
parent->rb_right = child;
|
|
}
|
|
else
|
|
root->rb_node = child;
|
|
|
|
if (node->rb_parent == old)
|
|
parent = node;
|
|
node->rb_parent = old->rb_parent;
|
|
node->rb_color = old->rb_color;
|
|
node->rb_right = old->rb_right;
|
|
node->rb_left = old->rb_left;
|
|
|
|
if (old->rb_parent)
|
|
{
|
|
if (old->rb_parent->rb_left == old)
|
|
old->rb_parent->rb_left = node;
|
|
else
|
|
old->rb_parent->rb_right = node;
|
|
} else
|
|
root->rb_node = node;
|
|
|
|
old->rb_left->rb_parent = node;
|
|
if (old->rb_right)
|
|
old->rb_right->rb_parent = node;
|
|
goto color;
|
|
}
|
|
|
|
parent = node->rb_parent;
|
|
color = node->rb_color;
|
|
|
|
if (child)
|
|
child->rb_parent = 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);
|
|
}
|
|
EXPORT_SYMBOL(rb_erase);
|
|
|
|
/*
|
|
* This function returns the first node (in sort order) of the tree.
|
|
*/
|
|
struct rb_node *rb_first(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;
|
|
}
|
|
EXPORT_SYMBOL(rb_first);
|
|
|
|
struct rb_node *rb_last(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;
|
|
}
|
|
EXPORT_SYMBOL(rb_last);
|
|
|
|
struct rb_node *rb_next(struct rb_node *node)
|
|
{
|
|
/* 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;
|
|
while (node->rb_left)
|
|
node=node->rb_left;
|
|
return 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 (node->rb_parent && node == node->rb_parent->rb_right)
|
|
node = node->rb_parent;
|
|
|
|
return node->rb_parent;
|
|
}
|
|
EXPORT_SYMBOL(rb_next);
|
|
|
|
struct rb_node *rb_prev(struct rb_node *node)
|
|
{
|
|
/* 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 (node->rb_parent && node == node->rb_parent->rb_left)
|
|
node = node->rb_parent;
|
|
|
|
return node->rb_parent;
|
|
}
|
|
EXPORT_SYMBOL(rb_prev);
|
|
|
|
void rb_replace_node(struct rb_node *victim, struct rb_node *new,
|
|
struct rb_root *root)
|
|
{
|
|
struct rb_node *parent = victim->rb_parent;
|
|
|
|
/* 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)
|
|
victim->rb_left->rb_parent = new;
|
|
if (victim->rb_right)
|
|
victim->rb_right->rb_parent = new;
|
|
|
|
/* Copy the pointers/colour from the victim to the replacement */
|
|
*new = *victim;
|
|
}
|
|
EXPORT_SYMBOL(rb_replace_node);
|