3 (C) 1999 Andrea Arcangeli <andrea@suse.de>
4 (C) 2002 David Woodhouse <dwmw2@infradead.org>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
25 static void __rb_rotate_left(struct fio_rb_node *node, struct rb_root *root)
27 struct fio_rb_node *right = node->rb_right;
28 struct fio_rb_node *parent = rb_parent(node);
30 if ((node->rb_right = right->rb_left))
31 rb_set_parent(right->rb_left, node);
32 right->rb_left = node;
34 rb_set_parent(right, parent);
38 if (node == parent->rb_left)
39 parent->rb_left = right;
41 parent->rb_right = right;
44 root->rb_node = right;
45 rb_set_parent(node, right);
48 static void __rb_rotate_right(struct fio_rb_node *node, struct rb_root *root)
50 struct fio_rb_node *left = node->rb_left;
51 struct fio_rb_node *parent = rb_parent(node);
53 if ((node->rb_left = left->rb_right))
54 rb_set_parent(left->rb_right, node);
55 left->rb_right = node;
57 rb_set_parent(left, parent);
61 if (node == parent->rb_right)
62 parent->rb_right = left;
64 parent->rb_left = left;
68 rb_set_parent(node, left);
71 void rb_insert_color(struct fio_rb_node *node, struct rb_root *root)
73 struct fio_rb_node *parent, *gparent;
75 while ((parent = rb_parent(node)) && rb_is_red(parent))
77 gparent = rb_parent(parent);
79 if (parent == gparent->rb_left)
82 register struct fio_rb_node *uncle = gparent->rb_right;
83 if (uncle && rb_is_red(uncle))
93 if (parent->rb_right == node)
95 register struct fio_rb_node *tmp;
96 __rb_rotate_left(parent, root);
102 rb_set_black(parent);
104 __rb_rotate_right(gparent, root);
107 register struct fio_rb_node *uncle = gparent->rb_left;
108 if (uncle && rb_is_red(uncle))
111 rb_set_black(parent);
118 if (parent->rb_left == node)
120 register struct fio_rb_node *tmp;
121 __rb_rotate_right(parent, root);
127 rb_set_black(parent);
129 __rb_rotate_left(gparent, root);
133 rb_set_black(root->rb_node);
136 static void __rb_erase_color(struct fio_rb_node *node,
137 struct fio_rb_node *parent,
138 struct rb_root *root)
140 struct fio_rb_node *other;
142 while ((!node || rb_is_black(node)) && node != root->rb_node)
144 if (parent->rb_left == node)
146 other = parent->rb_right;
147 if (rb_is_red(other))
151 __rb_rotate_left(parent, root);
152 other = parent->rb_right;
154 if ((!other->rb_left || rb_is_black(other->rb_left)) &&
155 (!other->rb_right || rb_is_black(other->rb_right)))
159 parent = rb_parent(node);
163 if (!other->rb_right || rb_is_black(other->rb_right))
165 struct fio_rb_node *o_left;
166 if ((o_left = other->rb_left))
167 rb_set_black(o_left);
169 __rb_rotate_right(other, root);
170 other = parent->rb_right;
172 rb_set_color(other, rb_color(parent));
173 rb_set_black(parent);
175 rb_set_black(other->rb_right);
176 __rb_rotate_left(parent, root);
177 node = root->rb_node;
183 other = parent->rb_left;
184 if (rb_is_red(other))
188 __rb_rotate_right(parent, root);
189 other = parent->rb_left;
191 if ((!other->rb_left || rb_is_black(other->rb_left)) &&
192 (!other->rb_right || rb_is_black(other->rb_right)))
196 parent = rb_parent(node);
200 if (!other->rb_left || rb_is_black(other->rb_left))
202 register struct fio_rb_node *o_right;
203 if ((o_right = other->rb_right))
204 rb_set_black(o_right);
206 __rb_rotate_left(other, root);
207 other = parent->rb_left;
209 rb_set_color(other, rb_color(parent));
210 rb_set_black(parent);
212 rb_set_black(other->rb_left);
213 __rb_rotate_right(parent, root);
214 node = root->rb_node;
223 void rb_erase(struct fio_rb_node *node, struct rb_root *root)
225 struct fio_rb_node *child, *parent;
229 child = node->rb_right;
230 else if (!node->rb_right)
231 child = node->rb_left;
234 struct fio_rb_node *old = node, *left;
236 node = node->rb_right;
237 while ((left = node->rb_left) != NULL)
239 child = node->rb_right;
240 parent = rb_parent(node);
241 color = rb_color(node);
244 rb_set_parent(child, parent);
246 parent->rb_right = child;
249 parent->rb_left = child;
251 node->rb_parent_color = old->rb_parent_color;
252 node->rb_right = old->rb_right;
253 node->rb_left = old->rb_left;
257 if (rb_parent(old)->rb_left == old)
258 rb_parent(old)->rb_left = node;
260 rb_parent(old)->rb_right = node;
262 root->rb_node = node;
264 rb_set_parent(old->rb_left, node);
266 rb_set_parent(old->rb_right, node);
270 parent = rb_parent(node);
271 color = rb_color(node);
274 rb_set_parent(child, parent);
277 if (parent->rb_left == node)
278 parent->rb_left = child;
280 parent->rb_right = child;
283 root->rb_node = child;
286 if (color == RB_BLACK)
287 __rb_erase_color(child, parent, root);
291 * This function returns the first node (in sort order) of the tree.
293 struct fio_rb_node *rb_first(struct rb_root *root)
295 struct fio_rb_node *n;
305 struct fio_rb_node *rb_next(const struct fio_rb_node *node)
307 struct fio_rb_node *parent;
309 if (RB_EMPTY_NODE(node))
313 * If we have a right-hand child, go down and then left as far
316 if (node->rb_right) {
317 node = node->rb_right;
318 while (node->rb_left)
320 return (struct fio_rb_node *)node;
324 * No right-hand children. Everything down and left is smaller than us,
325 * so any 'next' node must be in the general direction of our parent.
326 * Go up the tree; any time the ancestor is a right-hand child of its
327 * parent, keep going up. First time it's a left-hand child of its
328 * parent, said parent is our 'next' node.
330 while ((parent = rb_parent(node)) && node == parent->rb_right)