]>
git.ipfire.org Git - people/ms/u-boot.git/blob - lib/rbtree.c
3 (C) 1999 Andrea Arcangeli <andrea@suse.de>
4 (C) 2002 David Woodhouse <dwmw2@infradead.org>
6 * SPDX-License-Identifier: GPL-2.0+
11 #include <ubi_uboot.h>
12 #include <linux/rbtree.h>
14 static void __rb_rotate_left(struct rb_node
*node
, struct rb_root
*root
)
16 struct rb_node
*right
= node
->rb_right
;
17 struct rb_node
*parent
= rb_parent(node
);
19 if ((node
->rb_right
= right
->rb_left
))
20 rb_set_parent(right
->rb_left
, node
);
21 right
->rb_left
= node
;
23 rb_set_parent(right
, parent
);
27 if (node
== parent
->rb_left
)
28 parent
->rb_left
= right
;
30 parent
->rb_right
= right
;
33 root
->rb_node
= right
;
34 rb_set_parent(node
, right
);
37 static void __rb_rotate_right(struct rb_node
*node
, struct rb_root
*root
)
39 struct rb_node
*left
= node
->rb_left
;
40 struct rb_node
*parent
= rb_parent(node
);
42 if ((node
->rb_left
= left
->rb_right
))
43 rb_set_parent(left
->rb_right
, node
);
44 left
->rb_right
= node
;
46 rb_set_parent(left
, parent
);
50 if (node
== parent
->rb_right
)
51 parent
->rb_right
= left
;
53 parent
->rb_left
= left
;
57 rb_set_parent(node
, left
);
60 void rb_insert_color(struct rb_node
*node
, struct rb_root
*root
)
62 struct rb_node
*parent
, *gparent
;
64 while ((parent
= rb_parent(node
)) && rb_is_red(parent
))
66 gparent
= rb_parent(parent
);
68 if (parent
== gparent
->rb_left
)
71 register struct rb_node
*uncle
= gparent
->rb_right
;
72 if (uncle
&& rb_is_red(uncle
))
82 if (parent
->rb_right
== node
)
84 register struct rb_node
*tmp
;
85 __rb_rotate_left(parent
, root
);
93 __rb_rotate_right(gparent
, root
);
96 register struct rb_node
*uncle
= gparent
->rb_left
;
97 if (uncle
&& rb_is_red(uncle
))
100 rb_set_black(parent
);
107 if (parent
->rb_left
== node
)
109 register struct rb_node
*tmp
;
110 __rb_rotate_right(parent
, root
);
116 rb_set_black(parent
);
118 __rb_rotate_left(gparent
, root
);
122 rb_set_black(root
->rb_node
);
125 static void __rb_erase_color(struct rb_node
*node
, struct rb_node
*parent
,
126 struct rb_root
*root
)
128 struct rb_node
*other
;
130 while ((!node
|| rb_is_black(node
)) && node
!= root
->rb_node
)
132 if (parent
->rb_left
== node
)
134 other
= parent
->rb_right
;
135 if (rb_is_red(other
))
139 __rb_rotate_left(parent
, root
);
140 other
= parent
->rb_right
;
142 if ((!other
->rb_left
|| rb_is_black(other
->rb_left
)) &&
143 (!other
->rb_right
|| rb_is_black(other
->rb_right
)))
147 parent
= rb_parent(node
);
151 if (!other
->rb_right
|| rb_is_black(other
->rb_right
))
153 struct rb_node
*o_left
;
154 if ((o_left
= other
->rb_left
))
155 rb_set_black(o_left
);
157 __rb_rotate_right(other
, root
);
158 other
= parent
->rb_right
;
160 rb_set_color(other
, rb_color(parent
));
161 rb_set_black(parent
);
163 rb_set_black(other
->rb_right
);
164 __rb_rotate_left(parent
, root
);
165 node
= root
->rb_node
;
171 other
= parent
->rb_left
;
172 if (rb_is_red(other
))
176 __rb_rotate_right(parent
, root
);
177 other
= parent
->rb_left
;
179 if ((!other
->rb_left
|| rb_is_black(other
->rb_left
)) &&
180 (!other
->rb_right
|| rb_is_black(other
->rb_right
)))
184 parent
= rb_parent(node
);
188 if (!other
->rb_left
|| rb_is_black(other
->rb_left
))
190 register struct rb_node
*o_right
;
191 if ((o_right
= other
->rb_right
))
192 rb_set_black(o_right
);
194 __rb_rotate_left(other
, root
);
195 other
= parent
->rb_left
;
197 rb_set_color(other
, rb_color(parent
));
198 rb_set_black(parent
);
200 rb_set_black(other
->rb_left
);
201 __rb_rotate_right(parent
, root
);
202 node
= root
->rb_node
;
211 void rb_erase(struct rb_node
*node
, struct rb_root
*root
)
213 struct rb_node
*child
, *parent
;
217 child
= node
->rb_right
;
218 else if (!node
->rb_right
)
219 child
= node
->rb_left
;
222 struct rb_node
*old
= node
, *left
;
224 node
= node
->rb_right
;
225 while ((left
= node
->rb_left
) != NULL
)
227 child
= node
->rb_right
;
228 parent
= rb_parent(node
);
229 color
= rb_color(node
);
232 rb_set_parent(child
, parent
);
234 parent
->rb_right
= child
;
237 parent
->rb_left
= child
;
239 node
->rb_parent_color
= old
->rb_parent_color
;
240 node
->rb_right
= old
->rb_right
;
241 node
->rb_left
= old
->rb_left
;
245 if (rb_parent(old
)->rb_left
== old
)
246 rb_parent(old
)->rb_left
= node
;
248 rb_parent(old
)->rb_right
= node
;
250 root
->rb_node
= node
;
252 rb_set_parent(old
->rb_left
, node
);
254 rb_set_parent(old
->rb_right
, node
);
258 parent
= rb_parent(node
);
259 color
= rb_color(node
);
262 rb_set_parent(child
, parent
);
265 if (parent
->rb_left
== node
)
266 parent
->rb_left
= child
;
268 parent
->rb_right
= child
;
271 root
->rb_node
= child
;
274 if (color
== RB_BLACK
)
275 __rb_erase_color(child
, parent
, root
);
279 * This function returns the first node (in sort order) of the tree.
281 struct rb_node
*rb_first(struct rb_root
*root
)
293 struct rb_node
*rb_last(struct rb_root
*root
)
305 struct rb_node
*rb_next(struct rb_node
*node
)
307 struct rb_node
*parent
;
309 if (rb_parent(node
) == node
)
312 /* If we have a right-hand child, go down and then left as far
314 if (node
->rb_right
) {
315 node
= node
->rb_right
;
316 while (node
->rb_left
)
321 /* No right-hand children. Everything down and left is
322 smaller than us, so any 'next' node must be in the general
323 direction of our parent. Go up the tree; any time the
324 ancestor is a right-hand child of its parent, keep going
325 up. First time it's a left-hand child of its parent, said
326 parent is our 'next' node. */
327 while ((parent
= rb_parent(node
)) && node
== parent
->rb_right
)
333 struct rb_node
*rb_prev(struct rb_node
*node
)
335 struct rb_node
*parent
;
337 if (rb_parent(node
) == node
)
340 /* If we have a left-hand child, go down and then right as far
343 node
= node
->rb_left
;
344 while (node
->rb_right
)
349 /* No left-hand children. Go up till we find an ancestor which
350 is a right-hand child of its parent */
351 while ((parent
= rb_parent(node
)) && node
== parent
->rb_left
)
357 void rb_replace_node(struct rb_node
*victim
, struct rb_node
*new,
358 struct rb_root
*root
)
360 struct rb_node
*parent
= rb_parent(victim
);
362 /* Set the surrounding nodes to point to the replacement */
364 if (victim
== parent
->rb_left
)
365 parent
->rb_left
= new;
367 parent
->rb_right
= new;
372 rb_set_parent(victim
->rb_left
, new);
373 if (victim
->rb_right
)
374 rb_set_parent(victim
->rb_right
, new);
376 /* Copy the pointers/colour from the victim to the replacement */