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Commit | Line | Data |
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307bc971 ACM |
1 | /* |
2 | Red Black Trees | |
3 | (C) 1999 Andrea Arcangeli <andrea@suse.de> | |
4 | (C) 2002 David Woodhouse <dwmw2@infradead.org> | |
5 | (C) 2012 Michel Lespinasse <walken@google.com> | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
20 | ||
21 | tools/linux/include/linux/rbtree_augmented.h | |
22 | ||
23 | Copied from: | |
24 | linux/include/linux/rbtree_augmented.h | |
25 | */ | |
26 | ||
27 | #ifndef _TOOLS_LINUX_RBTREE_AUGMENTED_H | |
28 | #define _TOOLS_LINUX_RBTREE_AUGMENTED_H | |
29 | ||
30 | #include <linux/compiler.h> | |
31 | #include <linux/rbtree.h> | |
32 | ||
33 | /* | |
34 | * Please note - only struct rb_augment_callbacks and the prototypes for | |
35 | * rb_insert_augmented() and rb_erase_augmented() are intended to be public. | |
36 | * The rest are implementation details you are not expected to depend on. | |
37 | * | |
38 | * See Documentation/rbtree.txt for documentation and samples. | |
39 | */ | |
40 | ||
41 | struct rb_augment_callbacks { | |
42 | void (*propagate)(struct rb_node *node, struct rb_node *stop); | |
43 | void (*copy)(struct rb_node *old, struct rb_node *new); | |
44 | void (*rotate)(struct rb_node *old, struct rb_node *new); | |
45 | }; | |
46 | ||
47 | extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root, | |
48 | void (*augment_rotate)(struct rb_node *old, struct rb_node *new)); | |
49 | /* | |
50 | * Fixup the rbtree and update the augmented information when rebalancing. | |
51 | * | |
52 | * On insertion, the user must update the augmented information on the path | |
53 | * leading to the inserted node, then call rb_link_node() as usual and | |
54 | * rb_augment_inserted() instead of the usual rb_insert_color() call. | |
55 | * If rb_augment_inserted() rebalances the rbtree, it will callback into | |
56 | * a user provided function to update the augmented information on the | |
57 | * affected subtrees. | |
58 | */ | |
59 | static inline void | |
60 | rb_insert_augmented(struct rb_node *node, struct rb_root *root, | |
61 | const struct rb_augment_callbacks *augment) | |
62 | { | |
63 | __rb_insert_augmented(node, root, augment->rotate); | |
64 | } | |
65 | ||
66 | #define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield, \ | |
67 | rbtype, rbaugmented, rbcompute) \ | |
68 | static inline void \ | |
69 | rbname ## _propagate(struct rb_node *rb, struct rb_node *stop) \ | |
70 | { \ | |
71 | while (rb != stop) { \ | |
72 | rbstruct *node = rb_entry(rb, rbstruct, rbfield); \ | |
73 | rbtype augmented = rbcompute(node); \ | |
74 | if (node->rbaugmented == augmented) \ | |
75 | break; \ | |
76 | node->rbaugmented = augmented; \ | |
77 | rb = rb_parent(&node->rbfield); \ | |
78 | } \ | |
79 | } \ | |
80 | static inline void \ | |
81 | rbname ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \ | |
82 | { \ | |
83 | rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \ | |
84 | rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \ | |
85 | new->rbaugmented = old->rbaugmented; \ | |
86 | } \ | |
87 | static void \ | |
88 | rbname ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \ | |
89 | { \ | |
90 | rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \ | |
91 | rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \ | |
92 | new->rbaugmented = old->rbaugmented; \ | |
93 | old->rbaugmented = rbcompute(old); \ | |
94 | } \ | |
95 | rbstatic const struct rb_augment_callbacks rbname = { \ | |
96 | rbname ## _propagate, rbname ## _copy, rbname ## _rotate \ | |
97 | }; | |
98 | ||
99 | ||
100 | #define RB_RED 0 | |
101 | #define RB_BLACK 1 | |
102 | ||
103 | #define __rb_parent(pc) ((struct rb_node *)(pc & ~3)) | |
104 | ||
105 | #define __rb_color(pc) ((pc) & 1) | |
106 | #define __rb_is_black(pc) __rb_color(pc) | |
107 | #define __rb_is_red(pc) (!__rb_color(pc)) | |
108 | #define rb_color(rb) __rb_color((rb)->__rb_parent_color) | |
109 | #define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color) | |
110 | #define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color) | |
111 | ||
112 | static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p) | |
113 | { | |
114 | rb->__rb_parent_color = rb_color(rb) | (unsigned long)p; | |
115 | } | |
116 | ||
117 | static inline void rb_set_parent_color(struct rb_node *rb, | |
118 | struct rb_node *p, int color) | |
119 | { | |
120 | rb->__rb_parent_color = (unsigned long)p | color; | |
121 | } | |
122 | ||
123 | static inline void | |
124 | __rb_change_child(struct rb_node *old, struct rb_node *new, | |
125 | struct rb_node *parent, struct rb_root *root) | |
126 | { | |
127 | if (parent) { | |
128 | if (parent->rb_left == old) | |
129 | parent->rb_left = new; | |
130 | else | |
131 | parent->rb_right = new; | |
132 | } else | |
133 | root->rb_node = new; | |
134 | } | |
135 | ||
136 | extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root, | |
137 | void (*augment_rotate)(struct rb_node *old, struct rb_node *new)); | |
138 | ||
139 | static __always_inline struct rb_node * | |
140 | __rb_erase_augmented(struct rb_node *node, struct rb_root *root, | |
141 | const struct rb_augment_callbacks *augment) | |
142 | { | |
143 | struct rb_node *child = node->rb_right, *tmp = node->rb_left; | |
144 | struct rb_node *parent, *rebalance; | |
145 | unsigned long pc; | |
146 | ||
147 | if (!tmp) { | |
148 | /* | |
149 | * Case 1: node to erase has no more than 1 child (easy!) | |
150 | * | |
151 | * Note that if there is one child it must be red due to 5) | |
152 | * and node must be black due to 4). We adjust colors locally | |
153 | * so as to bypass __rb_erase_color() later on. | |
154 | */ | |
155 | pc = node->__rb_parent_color; | |
156 | parent = __rb_parent(pc); | |
157 | __rb_change_child(node, child, parent, root); | |
158 | if (child) { | |
159 | child->__rb_parent_color = pc; | |
160 | rebalance = NULL; | |
161 | } else | |
162 | rebalance = __rb_is_black(pc) ? parent : NULL; | |
163 | tmp = parent; | |
164 | } else if (!child) { | |
165 | /* Still case 1, but this time the child is node->rb_left */ | |
166 | tmp->__rb_parent_color = pc = node->__rb_parent_color; | |
167 | parent = __rb_parent(pc); | |
168 | __rb_change_child(node, tmp, parent, root); | |
169 | rebalance = NULL; | |
170 | tmp = parent; | |
171 | } else { | |
172 | struct rb_node *successor = child, *child2; | |
173 | tmp = child->rb_left; | |
174 | if (!tmp) { | |
175 | /* | |
176 | * Case 2: node's successor is its right child | |
177 | * | |
178 | * (n) (s) | |
179 | * / \ / \ | |
180 | * (x) (s) -> (x) (c) | |
181 | * \ | |
182 | * (c) | |
183 | */ | |
184 | parent = successor; | |
185 | child2 = successor->rb_right; | |
186 | augment->copy(node, successor); | |
187 | } else { | |
188 | /* | |
189 | * Case 3: node's successor is leftmost under | |
190 | * node's right child subtree | |
191 | * | |
192 | * (n) (s) | |
193 | * / \ / \ | |
194 | * (x) (y) -> (x) (y) | |
195 | * / / | |
196 | * (p) (p) | |
197 | * / / | |
198 | * (s) (c) | |
199 | * \ | |
200 | * (c) | |
201 | */ | |
202 | do { | |
203 | parent = successor; | |
204 | successor = tmp; | |
205 | tmp = tmp->rb_left; | |
206 | } while (tmp); | |
207 | parent->rb_left = child2 = successor->rb_right; | |
208 | successor->rb_right = child; | |
209 | rb_set_parent(child, successor); | |
210 | augment->copy(node, successor); | |
211 | augment->propagate(parent, successor); | |
212 | } | |
213 | ||
214 | successor->rb_left = tmp = node->rb_left; | |
215 | rb_set_parent(tmp, successor); | |
216 | ||
217 | pc = node->__rb_parent_color; | |
218 | tmp = __rb_parent(pc); | |
219 | __rb_change_child(node, successor, tmp, root); | |
220 | if (child2) { | |
221 | successor->__rb_parent_color = pc; | |
222 | rb_set_parent_color(child2, parent, RB_BLACK); | |
223 | rebalance = NULL; | |
224 | } else { | |
225 | unsigned long pc2 = successor->__rb_parent_color; | |
226 | successor->__rb_parent_color = pc; | |
227 | rebalance = __rb_is_black(pc2) ? parent : NULL; | |
228 | } | |
229 | tmp = successor; | |
230 | } | |
231 | ||
232 | augment->propagate(tmp, NULL); | |
233 | return rebalance; | |
234 | } | |
235 | ||
236 | static __always_inline void | |
237 | rb_erase_augmented(struct rb_node *node, struct rb_root *root, | |
238 | const struct rb_augment_callbacks *augment) | |
239 | { | |
240 | struct rb_node *rebalance = __rb_erase_augmented(node, root, augment); | |
241 | if (rebalance) | |
242 | __rb_erase_color(rebalance, root, augment->rotate); | |
243 | } | |
244 | ||
245 | #endif /* _TOOLS_LINUX_RBTREE_AUGMENTED_H */ |