diff options
author | David Woodhouse <dwmw2@infradead.org> | 2006-04-21 08:35:51 -0400 |
---|---|---|
committer | David Woodhouse <dwmw2@infradead.org> | 2006-04-21 08:35:51 -0400 |
commit | 55a981027fc393c86de2c4e7836c9515088a9a58 (patch) | |
tree | dd950b79d9f57ce48b2b2a91262b88eecb5296da /lib/rbtree.c | |
parent | 1975e59375756da4ff4e6e7d12f67485e813ace0 (diff) |
[RBTREE] Merge colour and parent fields of struct rb_node.
We only used a single bit for colour information, so having a whole
machine word of space allocated for it was a bit wasteful. Instead,
store it in the lowest bit of the 'parent' pointer, since that was
always going to be aligned anyway.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Diffstat (limited to 'lib/rbtree.c')
-rw-r--r-- | lib/rbtree.c | 178 |
1 files changed, 90 insertions, 88 deletions
diff --git a/lib/rbtree.c b/lib/rbtree.c index 63473e04f18a..4a7173cad149 100644 --- a/lib/rbtree.c +++ b/lib/rbtree.c | |||
@@ -26,60 +26,66 @@ | |||
26 | static void __rb_rotate_left(struct rb_node *node, struct rb_root *root) | 26 | static void __rb_rotate_left(struct rb_node *node, struct rb_root *root) |
27 | { | 27 | { |
28 | struct rb_node *right = node->rb_right; | 28 | struct rb_node *right = node->rb_right; |
29 | struct rb_node *parent = rb_parent(node); | ||
29 | 30 | ||
30 | if ((node->rb_right = right->rb_left)) | 31 | if ((node->rb_right = right->rb_left)) |
31 | right->rb_left->rb_parent = node; | 32 | rb_set_parent(right->rb_left, node); |
32 | right->rb_left = node; | 33 | right->rb_left = node; |
33 | 34 | ||
34 | if ((right->rb_parent = node->rb_parent)) | 35 | rb_set_parent(right, parent); |
36 | |||
37 | if (parent) | ||
35 | { | 38 | { |
36 | if (node == node->rb_parent->rb_left) | 39 | if (node == parent->rb_left) |
37 | node->rb_parent->rb_left = right; | 40 | parent->rb_left = right; |
38 | else | 41 | else |
39 | node->rb_parent->rb_right = right; | 42 | parent->rb_right = right; |
40 | } | 43 | } |
41 | else | 44 | else |
42 | root->rb_node = right; | 45 | root->rb_node = right; |
43 | node->rb_parent = right; | 46 | rb_set_parent(node, right); |
44 | } | 47 | } |
45 | 48 | ||
46 | static void __rb_rotate_right(struct rb_node *node, struct rb_root *root) | 49 | static void __rb_rotate_right(struct rb_node *node, struct rb_root *root) |
47 | { | 50 | { |
48 | struct rb_node *left = node->rb_left; | 51 | struct rb_node *left = node->rb_left; |
52 | struct rb_node *parent = rb_parent(node); | ||
49 | 53 | ||
50 | if ((node->rb_left = left->rb_right)) | 54 | if ((node->rb_left = left->rb_right)) |
51 | left->rb_right->rb_parent = node; | 55 | rb_set_parent(left->rb_right, node); |
52 | left->rb_right = node; | 56 | left->rb_right = node; |
53 | 57 | ||
54 | if ((left->rb_parent = node->rb_parent)) | 58 | rb_set_parent(left, parent); |
59 | |||
60 | if (parent) | ||
55 | { | 61 | { |
56 | if (node == node->rb_parent->rb_right) | 62 | if (node == parent->rb_right) |
57 | node->rb_parent->rb_right = left; | 63 | parent->rb_right = left; |
58 | else | 64 | else |
59 | node->rb_parent->rb_left = left; | 65 | parent->rb_left = left; |
60 | } | 66 | } |
61 | else | 67 | else |
62 | root->rb_node = left; | 68 | root->rb_node = left; |
63 | node->rb_parent = left; | 69 | rb_set_parent(node, left); |
64 | } | 70 | } |
65 | 71 | ||
66 | void rb_insert_color(struct rb_node *node, struct rb_root *root) | 72 | void rb_insert_color(struct rb_node *node, struct rb_root *root) |
67 | { | 73 | { |
68 | struct rb_node *parent, *gparent; | 74 | struct rb_node *parent, *gparent; |
69 | 75 | ||
70 | while ((parent = node->rb_parent) && parent->rb_color == RB_RED) | 76 | while ((parent = rb_parent(node)) && rb_is_red(parent)) |
71 | { | 77 | { |
72 | gparent = parent->rb_parent; | 78 | gparent = rb_parent(parent); |
73 | 79 | ||
74 | if (parent == gparent->rb_left) | 80 | if (parent == gparent->rb_left) |
75 | { | 81 | { |
76 | { | 82 | { |
77 | register struct rb_node *uncle = gparent->rb_right; | 83 | register struct rb_node *uncle = gparent->rb_right; |
78 | if (uncle && uncle->rb_color == RB_RED) | 84 | if (uncle && rb_is_red(uncle)) |
79 | { | 85 | { |
80 | uncle->rb_color = RB_BLACK; | 86 | rb_set_black(uncle); |
81 | parent->rb_color = RB_BLACK; | 87 | rb_set_black(parent); |
82 | gparent->rb_color = RB_RED; | 88 | rb_set_red(gparent); |
83 | node = gparent; | 89 | node = gparent; |
84 | continue; | 90 | continue; |
85 | } | 91 | } |
@@ -94,17 +100,17 @@ void rb_insert_color(struct rb_node *node, struct rb_root *root) | |||
94 | node = tmp; | 100 | node = tmp; |
95 | } | 101 | } |
96 | 102 | ||
97 | parent->rb_color = RB_BLACK; | 103 | rb_set_black(parent); |
98 | gparent->rb_color = RB_RED; | 104 | rb_set_red(gparent); |
99 | __rb_rotate_right(gparent, root); | 105 | __rb_rotate_right(gparent, root); |
100 | } else { | 106 | } else { |
101 | { | 107 | { |
102 | register struct rb_node *uncle = gparent->rb_left; | 108 | register struct rb_node *uncle = gparent->rb_left; |
103 | if (uncle && uncle->rb_color == RB_RED) | 109 | if (uncle && rb_is_red(uncle)) |
104 | { | 110 | { |
105 | uncle->rb_color = RB_BLACK; | 111 | rb_set_black(uncle); |
106 | parent->rb_color = RB_BLACK; | 112 | rb_set_black(parent); |
107 | gparent->rb_color = RB_RED; | 113 | rb_set_red(gparent); |
108 | node = gparent; | 114 | node = gparent; |
109 | continue; | 115 | continue; |
110 | } | 116 | } |
@@ -119,13 +125,13 @@ void rb_insert_color(struct rb_node *node, struct rb_root *root) | |||
119 | node = tmp; | 125 | node = tmp; |
120 | } | 126 | } |
121 | 127 | ||
122 | parent->rb_color = RB_BLACK; | 128 | rb_set_black(parent); |
123 | gparent->rb_color = RB_RED; | 129 | rb_set_red(gparent); |
124 | __rb_rotate_left(gparent, root); | 130 | __rb_rotate_left(gparent, root); |
125 | } | 131 | } |
126 | } | 132 | } |
127 | 133 | ||
128 | root->rb_node->rb_color = RB_BLACK; | 134 | rb_set_black(root->rb_node); |
129 | } | 135 | } |
130 | EXPORT_SYMBOL(rb_insert_color); | 136 | EXPORT_SYMBOL(rb_insert_color); |
131 | 137 | ||
@@ -134,43 +140,40 @@ static void __rb_erase_color(struct rb_node *node, struct rb_node *parent, | |||
134 | { | 140 | { |
135 | struct rb_node *other; | 141 | struct rb_node *other; |
136 | 142 | ||
137 | while ((!node || node->rb_color == RB_BLACK) && node != root->rb_node) | 143 | while ((!node || rb_is_black(node)) && node != root->rb_node) |
138 | { | 144 | { |
139 | if (parent->rb_left == node) | 145 | if (parent->rb_left == node) |
140 | { | 146 | { |
141 | other = parent->rb_right; | 147 | other = parent->rb_right; |
142 | if (other->rb_color == RB_RED) | 148 | if (rb_is_red(other)) |
143 | { | 149 | { |
144 | other->rb_color = RB_BLACK; | 150 | rb_set_black(other); |
145 | parent->rb_color = RB_RED; | 151 | rb_set_red(parent); |
146 | __rb_rotate_left(parent, root); | 152 | __rb_rotate_left(parent, root); |
147 | other = parent->rb_right; | 153 | other = parent->rb_right; |
148 | } | 154 | } |
149 | if ((!other->rb_left || | 155 | if ((!other->rb_left || rb_is_black(other->rb_left)) && |
150 | other->rb_left->rb_color == RB_BLACK) | 156 | (!other->rb_right || rb_is_black(other->rb_right))) |
151 | && (!other->rb_right || | ||
152 | other->rb_right->rb_color == RB_BLACK)) | ||
153 | { | 157 | { |
154 | other->rb_color = RB_RED; | 158 | rb_set_red(other); |
155 | node = parent; | 159 | node = parent; |
156 | parent = node->rb_parent; | 160 | parent = rb_parent(node); |
157 | } | 161 | } |
158 | else | 162 | else |
159 | { | 163 | { |
160 | if (!other->rb_right || | 164 | if (!other->rb_right || rb_is_black(other->rb_right)) |
161 | other->rb_right->rb_color == RB_BLACK) | ||
162 | { | 165 | { |
163 | register struct rb_node *o_left; | 166 | struct rb_node *o_left; |
164 | if ((o_left = other->rb_left)) | 167 | if ((o_left = other->rb_left)) |
165 | o_left->rb_color = RB_BLACK; | 168 | rb_set_black(o_left); |
166 | other->rb_color = RB_RED; | 169 | rb_set_red(other); |
167 | __rb_rotate_right(other, root); | 170 | __rb_rotate_right(other, root); |
168 | other = parent->rb_right; | 171 | other = parent->rb_right; |
169 | } | 172 | } |
170 | other->rb_color = parent->rb_color; | 173 | rb_set_colour(other, rb_colour(parent)); |
171 | parent->rb_color = RB_BLACK; | 174 | rb_set_black(parent); |
172 | if (other->rb_right) | 175 | if (other->rb_right) |
173 | other->rb_right->rb_color = RB_BLACK; | 176 | rb_set_black(other->rb_right); |
174 | __rb_rotate_left(parent, root); | 177 | __rb_rotate_left(parent, root); |
175 | node = root->rb_node; | 178 | node = root->rb_node; |
176 | break; | 179 | break; |
@@ -179,38 +182,35 @@ static void __rb_erase_color(struct rb_node *node, struct rb_node *parent, | |||
179 | else | 182 | else |
180 | { | 183 | { |
181 | other = parent->rb_left; | 184 | other = parent->rb_left; |
182 | if (other->rb_color == RB_RED) | 185 | if (rb_is_red(other)) |
183 | { | 186 | { |
184 | other->rb_color = RB_BLACK; | 187 | rb_set_black(other); |
185 | parent->rb_color = RB_RED; | 188 | rb_set_red(parent); |
186 | __rb_rotate_right(parent, root); | 189 | __rb_rotate_right(parent, root); |
187 | other = parent->rb_left; | 190 | other = parent->rb_left; |
188 | } | 191 | } |
189 | if ((!other->rb_left || | 192 | if ((!other->rb_left || rb_is_black(other->rb_left)) && |
190 | other->rb_left->rb_color == RB_BLACK) | 193 | (!other->rb_right || rb_is_black(other->rb_right))) |
191 | && (!other->rb_right || | ||
192 | other->rb_right->rb_color == RB_BLACK)) | ||
193 | { | 194 | { |
194 | other->rb_color = RB_RED; | 195 | rb_set_red(other); |
195 | node = parent; | 196 | node = parent; |
196 | parent = node->rb_parent; | 197 | parent = rb_parent(node); |
197 | } | 198 | } |
198 | else | 199 | else |
199 | { | 200 | { |
200 | if (!other->rb_left || | 201 | if (!other->rb_left || rb_is_black(other->rb_left)) |
201 | other->rb_left->rb_color == RB_BLACK) | ||
202 | { | 202 | { |
203 | register struct rb_node *o_right; | 203 | register struct rb_node *o_right; |
204 | if ((o_right = other->rb_right)) | 204 | if ((o_right = other->rb_right)) |
205 | o_right->rb_color = RB_BLACK; | 205 | rb_set_black(o_right); |
206 | other->rb_color = RB_RED; | 206 | rb_set_red(other); |
207 | __rb_rotate_left(other, root); | 207 | __rb_rotate_left(other, root); |
208 | other = parent->rb_left; | 208 | other = parent->rb_left; |
209 | } | 209 | } |
210 | other->rb_color = parent->rb_color; | 210 | rb_set_colour(other, rb_colour(parent)); |
211 | parent->rb_color = RB_BLACK; | 211 | rb_set_black(parent); |
212 | if (other->rb_left) | 212 | if (other->rb_left) |
213 | other->rb_left->rb_color = RB_BLACK; | 213 | rb_set_black(other->rb_left); |
214 | __rb_rotate_right(parent, root); | 214 | __rb_rotate_right(parent, root); |
215 | node = root->rb_node; | 215 | node = root->rb_node; |
216 | break; | 216 | break; |
@@ -218,7 +218,7 @@ static void __rb_erase_color(struct rb_node *node, struct rb_node *parent, | |||
218 | } | 218 | } |
219 | } | 219 | } |
220 | if (node) | 220 | if (node) |
221 | node->rb_color = RB_BLACK; | 221 | rb_set_black(node); |
222 | } | 222 | } |
223 | 223 | ||
224 | void rb_erase(struct rb_node *node, struct rb_root *root) | 224 | void rb_erase(struct rb_node *node, struct rb_root *root) |
@@ -238,43 +238,41 @@ void rb_erase(struct rb_node *node, struct rb_root *root) | |||
238 | while ((left = node->rb_left) != NULL) | 238 | while ((left = node->rb_left) != NULL) |
239 | node = left; | 239 | node = left; |
240 | child = node->rb_right; | 240 | child = node->rb_right; |
241 | parent = node->rb_parent; | 241 | parent = rb_parent(node); |
242 | color = node->rb_color; | 242 | color = rb_colour(node); |
243 | 243 | ||
244 | if (child) | 244 | if (child) |
245 | child->rb_parent = parent; | 245 | rb_set_parent(child, parent); |
246 | 246 | if (parent == old) { | |
247 | if (node->rb_parent == old) { | ||
248 | parent->rb_right = child; | 247 | parent->rb_right = child; |
249 | parent = node; | 248 | parent = node; |
250 | } else | 249 | } else |
251 | parent->rb_left = child; | 250 | parent->rb_left = child; |
252 | 251 | ||
253 | node->rb_parent = old->rb_parent; | 252 | node->rb_parent_colour = old->rb_parent_colour; |
254 | node->rb_color = old->rb_color; | ||
255 | node->rb_right = old->rb_right; | 253 | node->rb_right = old->rb_right; |
256 | node->rb_left = old->rb_left; | 254 | node->rb_left = old->rb_left; |
257 | 255 | ||
258 | if (old->rb_parent) | 256 | if (rb_parent(old)) |
259 | { | 257 | { |
260 | if (old->rb_parent->rb_left == old) | 258 | if (rb_parent(old)->rb_left == old) |
261 | old->rb_parent->rb_left = node; | 259 | rb_parent(old)->rb_left = node; |
262 | else | 260 | else |
263 | old->rb_parent->rb_right = node; | 261 | rb_parent(old)->rb_right = node; |
264 | } else | 262 | } else |
265 | root->rb_node = node; | 263 | root->rb_node = node; |
266 | 264 | ||
267 | old->rb_left->rb_parent = node; | 265 | rb_set_parent(old->rb_left, node); |
268 | if (old->rb_right) | 266 | if (old->rb_right) |
269 | old->rb_right->rb_parent = node; | 267 | rb_set_parent(old->rb_right, node); |
270 | goto color; | 268 | goto color; |
271 | } | 269 | } |
272 | 270 | ||
273 | parent = node->rb_parent; | 271 | parent = rb_parent(node); |
274 | color = node->rb_color; | 272 | color = rb_colour(node); |
275 | 273 | ||
276 | if (child) | 274 | if (child) |
277 | child->rb_parent = parent; | 275 | rb_set_parent(child, parent); |
278 | if (parent) | 276 | if (parent) |
279 | { | 277 | { |
280 | if (parent->rb_left == node) | 278 | if (parent->rb_left == node) |
@@ -322,6 +320,8 @@ EXPORT_SYMBOL(rb_last); | |||
322 | 320 | ||
323 | struct rb_node *rb_next(struct rb_node *node) | 321 | struct rb_node *rb_next(struct rb_node *node) |
324 | { | 322 | { |
323 | struct rb_node *parent; | ||
324 | |||
325 | /* If we have a right-hand child, go down and then left as far | 325 | /* If we have a right-hand child, go down and then left as far |
326 | as we can. */ | 326 | as we can. */ |
327 | if (node->rb_right) { | 327 | if (node->rb_right) { |
@@ -337,15 +337,17 @@ struct rb_node *rb_next(struct rb_node *node) | |||
337 | ancestor is a right-hand child of its parent, keep going | 337 | ancestor is a right-hand child of its parent, keep going |
338 | up. First time it's a left-hand child of its parent, said | 338 | up. First time it's a left-hand child of its parent, said |
339 | parent is our 'next' node. */ | 339 | parent is our 'next' node. */ |
340 | while (node->rb_parent && node == node->rb_parent->rb_right) | 340 | while ((parent = rb_parent(node)) && node == parent->rb_right) |
341 | node = node->rb_parent; | 341 | node = parent; |
342 | 342 | ||
343 | return node->rb_parent; | 343 | return parent; |
344 | } | 344 | } |
345 | EXPORT_SYMBOL(rb_next); | 345 | EXPORT_SYMBOL(rb_next); |
346 | 346 | ||
347 | struct rb_node *rb_prev(struct rb_node *node) | 347 | struct rb_node *rb_prev(struct rb_node *node) |
348 | { | 348 | { |
349 | struct rb_node *parent; | ||
350 | |||
349 | /* If we have a left-hand child, go down and then right as far | 351 | /* If we have a left-hand child, go down and then right as far |
350 | as we can. */ | 352 | as we can. */ |
351 | if (node->rb_left) { | 353 | if (node->rb_left) { |
@@ -357,17 +359,17 @@ struct rb_node *rb_prev(struct rb_node *node) | |||
357 | 359 | ||
358 | /* No left-hand children. Go up till we find an ancestor which | 360 | /* No left-hand children. Go up till we find an ancestor which |
359 | is a right-hand child of its parent */ | 361 | is a right-hand child of its parent */ |
360 | while (node->rb_parent && node == node->rb_parent->rb_left) | 362 | while ((parent = rb_parent(node)) && node == parent->rb_left) |
361 | node = node->rb_parent; | 363 | node = parent; |
362 | 364 | ||
363 | return node->rb_parent; | 365 | return parent; |
364 | } | 366 | } |
365 | EXPORT_SYMBOL(rb_prev); | 367 | EXPORT_SYMBOL(rb_prev); |
366 | 368 | ||
367 | void rb_replace_node(struct rb_node *victim, struct rb_node *new, | 369 | void rb_replace_node(struct rb_node *victim, struct rb_node *new, |
368 | struct rb_root *root) | 370 | struct rb_root *root) |
369 | { | 371 | { |
370 | struct rb_node *parent = victim->rb_parent; | 372 | struct rb_node *parent = rb_parent(victim); |
371 | 373 | ||
372 | /* Set the surrounding nodes to point to the replacement */ | 374 | /* Set the surrounding nodes to point to the replacement */ |
373 | if (parent) { | 375 | if (parent) { |
@@ -379,9 +381,9 @@ void rb_replace_node(struct rb_node *victim, struct rb_node *new, | |||
379 | root->rb_node = new; | 381 | root->rb_node = new; |
380 | } | 382 | } |
381 | if (victim->rb_left) | 383 | if (victim->rb_left) |
382 | victim->rb_left->rb_parent = new; | 384 | rb_set_parent(victim->rb_left, new); |
383 | if (victim->rb_right) | 385 | if (victim->rb_right) |
384 | victim->rb_right->rb_parent = new; | 386 | rb_set_parent(victim->rb_right, new); |
385 | 387 | ||
386 | /* Copy the pointers/colour from the victim to the replacement */ | 388 | /* Copy the pointers/colour from the victim to the replacement */ |
387 | *new = *victim; | 389 | *new = *victim; |