rbtree

annotate src/rbtree.c @ 7:2c0baa1fd419

find changesets by author, revision, files, or words in the commit message
del_tree would call 0 if the del func is null
author John Tsiombikas <nuclear@member.fsf.org>
date Fri, 21 Oct 2011 11:32:38 +0300
parents 56a08d00bb41
children b45febfd2922
rev   line source
nuclear@0 1 #include <stdio.h>
nuclear@0 2 #include <stdlib.h>
nuclear@0 3 #include <string.h>
nuclear@0 4 #include "rbtree.h"
nuclear@0 5
nuclear@0 6 #define INT2PTR(x) ((void*)(x))
nuclear@0 7 #define PTR2INT(x) ((int)(x))
nuclear@0 8
nuclear@0 9 struct rbtree {
nuclear@0 10 struct rbnode *root;
nuclear@0 11
nuclear@0 12 rb_alloc_func_t alloc;
nuclear@0 13 rb_free_func_t free;
nuclear@0 14
nuclear@0 15 rb_cmp_func_t cmp;
nuclear@0 16 rb_del_func_t del;
nuclear@0 17 void *del_cls;
nuclear@0 18
nuclear@0 19 struct rbnode *rstack, *iter;
nuclear@0 20 };
nuclear@0 21
nuclear@0 22 static int cmpaddr(void *ap, void *bp);
nuclear@0 23 static int cmpint(void *ap, void *bp);
nuclear@0 24
nuclear@0 25 static int count_nodes(struct rbnode *node);
nuclear@0 26 static void del_tree(struct rbnode *node, void (*delfunc)(struct rbnode*, void*), void *cls);
nuclear@0 27 static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data);
nuclear@0 28 static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key);
nuclear@3 29 /*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key);*/
nuclear@0 30 static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls);
nuclear@0 31
nuclear@0 32 struct rbtree *rb_create(rb_cmp_func_t cmp_func)
nuclear@0 33 {
nuclear@0 34 struct rbtree *rb;
nuclear@0 35
nuclear@0 36 if(!(rb = malloc(sizeof *rb))) {
nuclear@0 37 return 0;
nuclear@0 38 }
nuclear@0 39 if(rb_init(rb, cmp_func) == -1) {
nuclear@0 40 free(rb);
nuclear@0 41 return 0;
nuclear@0 42 }
nuclear@0 43 return rb;
nuclear@0 44 }
nuclear@0 45
nuclear@0 46 void rb_free(struct rbtree *rb)
nuclear@0 47 {
nuclear@0 48 rb_destroy(rb);
nuclear@0 49 free(rb);
nuclear@0 50 }
nuclear@0 51
nuclear@0 52
nuclear@0 53 int rb_init(struct rbtree *rb, rb_cmp_func_t cmp_func)
nuclear@0 54 {
nuclear@0 55 memset(rb, 0, sizeof *rb);
nuclear@0 56
nuclear@0 57 if(cmp_func == RB_KEY_INT) {
nuclear@0 58 rb->cmp = cmpint;
nuclear@0 59 } else if(cmp_func == RB_KEY_STRING) {
nuclear@0 60 rb->cmp = (rb_cmp_func_t)strcmp;
nuclear@0 61 } else {
nuclear@0 62 rb->cmp = cmpaddr;
nuclear@0 63 }
nuclear@0 64
nuclear@0 65 rb->alloc = malloc;
nuclear@0 66 rb->free = free;
nuclear@0 67 return 0;
nuclear@0 68 }
nuclear@0 69
nuclear@0 70 void rb_destroy(struct rbtree *rb)
nuclear@0 71 {
nuclear@0 72 del_tree(rb->root, rb->del, rb->del_cls);
nuclear@0 73 }
nuclear@0 74
nuclear@0 75 void rb_set_allocator(struct rbtree *rb, rb_alloc_func_t alloc, rb_free_func_t free)
nuclear@0 76 {
nuclear@0 77 rb->alloc = alloc;
nuclear@0 78 rb->free = free;
nuclear@0 79 }
nuclear@0 80
nuclear@0 81
nuclear@0 82 void rb_set_compare_func(struct rbtree *rb, rb_cmp_func_t func)
nuclear@0 83 {
nuclear@0 84 rb->cmp = func;
nuclear@0 85 }
nuclear@0 86
nuclear@0 87 void rb_set_delete_func(struct rbtree *rb, rb_del_func_t func, void *cls)
nuclear@0 88 {
nuclear@0 89 rb->del = func;
nuclear@0 90 rb->del_cls = cls;
nuclear@0 91 }
nuclear@0 92
nuclear@5 93
nuclear@5 94 void rb_clear(struct rbtree *rb)
nuclear@5 95 {
nuclear@5 96 del_tree(rb->root, rb->del, rb->del_cls);
nuclear@5 97 rb->root = 0;
nuclear@5 98 }
nuclear@5 99
nuclear@5 100 int rb_copy(struct rbtree *dest, struct rbtree *src)
nuclear@5 101 {
nuclear@5 102 struct rbnode *node;
nuclear@5 103
nuclear@5 104 rb_clear(dest);
nuclear@5 105 rb_begin(src);
nuclear@5 106 while((node = rb_next(src))) {
nuclear@5 107 if(rb_insert(dest, node->key, node->data) == -1) {
nuclear@5 108 return -1;
nuclear@5 109 }
nuclear@5 110 }
nuclear@5 111 return 0;
nuclear@5 112 }
nuclear@5 113
nuclear@0 114 int rb_size(struct rbtree *rb)
nuclear@0 115 {
nuclear@0 116 return count_nodes(rb->root);
nuclear@0 117 }
nuclear@0 118
nuclear@0 119 int rb_insert(struct rbtree *rb, void *key, void *data)
nuclear@0 120 {
nuclear@0 121 rb->root = insert(rb, rb->root, key, data);
nuclear@0 122 rb->root->red = 0;
nuclear@0 123 return 0;
nuclear@0 124 }
nuclear@0 125
nuclear@0 126 int rb_inserti(struct rbtree *rb, int key, void *data)
nuclear@0 127 {
nuclear@0 128 rb->root = insert(rb, rb->root, INT2PTR(key), data);
nuclear@0 129 rb->root->red = 0;
nuclear@0 130 return 0;
nuclear@0 131 }
nuclear@0 132
nuclear@0 133
nuclear@0 134 int rb_delete(struct rbtree *rb, void *key)
nuclear@0 135 {
nuclear@0 136 rb->root = delete(rb, rb->root, key);
nuclear@0 137 rb->root->red = 0;
nuclear@0 138 return 0;
nuclear@0 139 }
nuclear@0 140
nuclear@0 141 int rb_deletei(struct rbtree *rb, int key)
nuclear@0 142 {
nuclear@0 143 rb->root = delete(rb, rb->root, INT2PTR(key));
nuclear@0 144 rb->root->red = 0;
nuclear@0 145 return 0;
nuclear@0 146 }
nuclear@0 147
nuclear@0 148
nuclear@0 149 void *rb_find(struct rbtree *rb, void *key)
nuclear@0 150 {
nuclear@3 151 struct rbnode *node = rb->root;
nuclear@3 152
nuclear@3 153 while(node) {
nuclear@3 154 int cmp = rb->cmp(key, node->key);
nuclear@3 155 if(cmp == 0) {
nuclear@3 156 return node;
nuclear@3 157 }
nuclear@3 158 node = cmp < 0 ? node->left : node->right;
nuclear@3 159 }
nuclear@3 160 return 0;
nuclear@0 161 }
nuclear@0 162
nuclear@0 163 void *rb_findi(struct rbtree *rb, int key)
nuclear@0 164 {
nuclear@3 165 return rb_find(rb, INT2PTR(key));
nuclear@0 166 }
nuclear@0 167
nuclear@0 168
nuclear@0 169 void rb_foreach(struct rbtree *rb, void (*func)(struct rbnode*, void*), void *cls)
nuclear@0 170 {
nuclear@0 171 traverse(rb->root, func, cls);
nuclear@0 172 }
nuclear@0 173
nuclear@0 174
nuclear@0 175 struct rbnode *rb_root(struct rbtree *rb)
nuclear@0 176 {
nuclear@0 177 return rb->root;
nuclear@0 178 }
nuclear@0 179
nuclear@0 180 void rb_begin(struct rbtree *rb)
nuclear@0 181 {
nuclear@0 182 rb->rstack = 0;
nuclear@0 183 rb->iter = rb->root;
nuclear@0 184 }
nuclear@0 185
nuclear@0 186 #define push(sp, x) ((x)->next = (sp), (sp) = (x))
nuclear@0 187 #define pop(sp) ((sp) = (sp)->next)
nuclear@0 188 #define top(sp) (sp)
nuclear@0 189
nuclear@0 190 struct rbnode *rb_next(struct rbtree *rb)
nuclear@0 191 {
nuclear@0 192 struct rbnode *res = 0;
nuclear@0 193
nuclear@0 194 while(rb->rstack || rb->iter) {
nuclear@0 195 if(rb->iter) {
nuclear@0 196 push(rb->rstack, rb->iter);
nuclear@0 197 rb->iter = rb->iter->left;
nuclear@0 198 } else {
nuclear@0 199 rb->iter = top(rb->rstack);
nuclear@0 200 pop(rb->rstack);
nuclear@0 201 res = rb->iter;
nuclear@0 202 rb->iter = rb->iter->right;
nuclear@0 203 break;
nuclear@0 204 }
nuclear@0 205 }
nuclear@0 206 return res;
nuclear@0 207 }
nuclear@0 208
nuclear@0 209 void *rb_node_key(struct rbnode *node)
nuclear@0 210 {
nuclear@0 211 return node ? node->key : 0;
nuclear@0 212 }
nuclear@0 213
nuclear@0 214 int rb_node_keyi(struct rbnode *node)
nuclear@0 215 {
nuclear@0 216 return node ? PTR2INT(node->key) : 0;
nuclear@0 217 }
nuclear@0 218
nuclear@0 219 void *rb_node_data(struct rbnode *node)
nuclear@0 220 {
nuclear@0 221 return node ? node->data : 0;
nuclear@0 222 }
nuclear@0 223
nuclear@0 224 static int cmpaddr(void *ap, void *bp)
nuclear@0 225 {
nuclear@0 226 return ap < bp ? -1 : (ap > bp ? 1 : 0);
nuclear@0 227 }
nuclear@0 228
nuclear@0 229 static int cmpint(void *ap, void *bp)
nuclear@0 230 {
nuclear@0 231 return PTR2INT(ap) - PTR2INT(bp);
nuclear@0 232 }
nuclear@0 233
nuclear@0 234
nuclear@0 235 /* ---- left-leaning 2-3 red-black implementation ---- */
nuclear@0 236
nuclear@0 237 /* helper prototypes */
nuclear@0 238 static int is_red(struct rbnode *tree);
nuclear@0 239 static void color_flip(struct rbnode *tree);
nuclear@0 240 static struct rbnode *rot_left(struct rbnode *a);
nuclear@0 241 static struct rbnode *rot_right(struct rbnode *a);
nuclear@0 242 static struct rbnode *find_min(struct rbnode *tree);
nuclear@0 243 static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree);
nuclear@0 244 /*static struct rbnode *move_red_right(struct rbnode *tree);*/
nuclear@0 245 static struct rbnode *move_red_left(struct rbnode *tree);
nuclear@0 246 static struct rbnode *fix_up(struct rbnode *tree);
nuclear@0 247
nuclear@0 248 static int count_nodes(struct rbnode *node)
nuclear@0 249 {
nuclear@0 250 if(!node)
nuclear@0 251 return 0;
nuclear@0 252
nuclear@0 253 return 1 + count_nodes(node->left) + count_nodes(node->right);
nuclear@0 254 }
nuclear@0 255
nuclear@0 256 static void del_tree(struct rbnode *node, rb_del_func_t delfunc, void *cls)
nuclear@0 257 {
nuclear@0 258 if(!node)
nuclear@0 259 return;
nuclear@0 260
nuclear@0 261 del_tree(node->left, delfunc, cls);
nuclear@0 262 del_tree(node->right, delfunc, cls);
nuclear@0 263
nuclear@7 264 if(delfunc) {
nuclear@7 265 delfunc(node, cls);
nuclear@7 266 }
nuclear@0 267 free(node);
nuclear@0 268 }
nuclear@0 269
nuclear@0 270 static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data)
nuclear@0 271 {
nuclear@0 272 int cmp;
nuclear@0 273
nuclear@0 274 if(!tree) {
nuclear@0 275 struct rbnode *node = rb->alloc(sizeof *node);
nuclear@0 276 node->red = 1;
nuclear@0 277 node->key = key;
nuclear@0 278 node->data = data;
nuclear@0 279 node->left = node->right = 0;
nuclear@0 280 return node;
nuclear@0 281 }
nuclear@0 282
nuclear@0 283 cmp = rb->cmp(key, tree->key);
nuclear@0 284
nuclear@0 285 if(cmp < 0) {
nuclear@0 286 tree->left = insert(rb, tree->left, key, data);
nuclear@0 287 } else if(cmp > 0) {
nuclear@0 288 tree->right = insert(rb, tree->right, key, data);
nuclear@0 289 } else {
nuclear@0 290 tree->data = data;
nuclear@0 291 }
nuclear@0 292
nuclear@0 293 /* fix right-leaning reds */
nuclear@0 294 if(is_red(tree->right)) {
nuclear@0 295 tree = rot_left(tree);
nuclear@0 296 }
nuclear@0 297 /* fix two reds in a row */
nuclear@0 298 if(is_red(tree->left) && is_red(tree->left->left)) {
nuclear@0 299 tree = rot_right(tree);
nuclear@0 300 }
nuclear@0 301
nuclear@0 302 /* if 4-node, split it by color inversion */
nuclear@0 303 if(is_red(tree->left) && is_red(tree->right)) {
nuclear@0 304 color_flip(tree);
nuclear@0 305 }
nuclear@0 306
nuclear@0 307 return tree;
nuclear@0 308 }
nuclear@0 309
nuclear@0 310 static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key)
nuclear@0 311 {
nuclear@0 312 int cmp;
nuclear@0 313
nuclear@0 314 if(!tree) {
nuclear@0 315 return 0;
nuclear@0 316 }
nuclear@0 317
nuclear@0 318 cmp = rb->cmp(key, tree->key);
nuclear@0 319
nuclear@0 320 if(cmp < 0) {
nuclear@0 321 if(!is_red(tree->left) && !is_red(tree->left->left)) {
nuclear@0 322 tree = move_red_left(tree);
nuclear@0 323 }
nuclear@0 324 tree->left = delete(rb, tree->left, key);
nuclear@0 325 } else {
nuclear@0 326 /* need reds on the right */
nuclear@0 327 if(is_red(tree->left)) {
nuclear@0 328 tree = rot_right(tree);
nuclear@0 329 }
nuclear@0 330
nuclear@0 331 /* found it at the bottom (XXX what certifies left is null?) */
nuclear@0 332 if(cmp == 0 && !tree->right) {
nuclear@0 333 if(rb->del) {
nuclear@0 334 rb->del(tree, rb->del_cls);
nuclear@0 335 }
nuclear@0 336 rb->free(tree);
nuclear@0 337 return 0;
nuclear@0 338 }
nuclear@0 339
nuclear@0 340 if(!is_red(tree->right) && !is_red(tree->right->left)) {
nuclear@0 341 tree = move_red_left(tree);
nuclear@0 342 }
nuclear@0 343
nuclear@0 344 if(key == tree->key) {
nuclear@0 345 struct rbnode *rmin = find_min(tree->right);
nuclear@0 346 tree->key = rmin->key;
nuclear@0 347 tree->data = rmin->data;
nuclear@0 348 tree->right = del_min(rb, tree->right);
nuclear@0 349 } else {
nuclear@0 350 tree->right = delete(rb, tree->right, key);
nuclear@0 351 }
nuclear@0 352 }
nuclear@0 353
nuclear@0 354 return fix_up(tree);
nuclear@0 355 }
nuclear@0 356
nuclear@3 357 /*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key)
nuclear@0 358 {
nuclear@0 359 int cmp;
nuclear@0 360
nuclear@0 361 if(!node)
nuclear@0 362 return 0;
nuclear@0 363
nuclear@0 364 if((cmp = rb->cmp(key, node->key)) == 0) {
nuclear@0 365 return node;
nuclear@0 366 }
nuclear@0 367 return find(rb, cmp < 0 ? node->left : node->right, key);
nuclear@3 368 }*/
nuclear@0 369
nuclear@0 370 static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls)
nuclear@0 371 {
nuclear@0 372 if(!node)
nuclear@0 373 return;
nuclear@0 374
nuclear@0 375 traverse(node->left, func, cls);
nuclear@0 376 func(node, cls);
nuclear@0 377 traverse(node->right, func, cls);
nuclear@0 378 }
nuclear@0 379
nuclear@0 380 /* helpers */
nuclear@0 381
nuclear@0 382 static int is_red(struct rbnode *tree)
nuclear@0 383 {
nuclear@0 384 return tree && tree->red;
nuclear@0 385 }
nuclear@0 386
nuclear@0 387 static void color_flip(struct rbnode *tree)
nuclear@0 388 {
nuclear@0 389 tree->red = !tree->red;
nuclear@0 390 tree->left->red = !tree->left->red;
nuclear@0 391 tree->right->red = !tree->right->red;
nuclear@0 392 }
nuclear@0 393
nuclear@0 394 static struct rbnode *rot_left(struct rbnode *a)
nuclear@0 395 {
nuclear@0 396 struct rbnode *b = a->right;
nuclear@0 397 a->right = b->left;
nuclear@0 398 b->left = a;
nuclear@0 399 b->red = a->red;
nuclear@0 400 a->red = 1;
nuclear@0 401 return b;
nuclear@0 402 }
nuclear@0 403
nuclear@0 404 static struct rbnode *rot_right(struct rbnode *a)
nuclear@0 405 {
nuclear@0 406 struct rbnode *b = a->left;
nuclear@0 407 a->left = b->right;
nuclear@0 408 b->right = a;
nuclear@0 409 b->red = a->red;
nuclear@0 410 a->red = 1;
nuclear@0 411 return b;
nuclear@0 412 }
nuclear@0 413
nuclear@0 414 static struct rbnode *find_min(struct rbnode *tree)
nuclear@0 415 {
nuclear@3 416 struct rbnode *node;
nuclear@3 417
nuclear@3 418 if(!tree)
nuclear@3 419 return 0;
nuclear@3 420
nuclear@3 421 while(node->left) {
nuclear@3 422 node = node->left;
nuclear@0 423 }
nuclear@3 424 return node;
nuclear@0 425 }
nuclear@0 426
nuclear@0 427 static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree)
nuclear@0 428 {
nuclear@0 429 if(!tree->left) {
nuclear@0 430 if(rb->del) {
nuclear@0 431 rb->del(tree->left, rb->del_cls);
nuclear@0 432 }
nuclear@0 433 rb->free(tree->left);
nuclear@0 434 return 0;
nuclear@0 435 }
nuclear@0 436
nuclear@0 437 /* make sure we've got red (3/4-nodes) at the left side so we can delete at the bottom */
nuclear@0 438 if(!is_red(tree->left) && !is_red(tree->left->left)) {
nuclear@0 439 tree = move_red_left(tree);
nuclear@0 440 }
nuclear@0 441 tree->left = del_min(rb, tree->left);
nuclear@0 442
nuclear@0 443 /* fix right-reds, red-reds, and split 4-nodes on the way up */
nuclear@0 444 return fix_up(tree);
nuclear@0 445 }
nuclear@0 446
nuclear@0 447 #if 0
nuclear@0 448 /* push a red link on this node to the right */
nuclear@0 449 static struct rbnode *move_red_right(struct rbnode *tree)
nuclear@0 450 {
nuclear@0 451 /* flipping it makes both children go red, so we have a red to the right */
nuclear@0 452 color_flip(tree);
nuclear@0 453
nuclear@0 454 /* if after the flip we've got a red-red situation to the left, fix it */
nuclear@0 455 if(is_red(tree->left->left)) {
nuclear@0 456 tree = rot_right(tree);
nuclear@0 457 color_flip(tree);
nuclear@0 458 }
nuclear@0 459 return tree;
nuclear@0 460 }
nuclear@0 461 #endif
nuclear@0 462
nuclear@0 463 /* push a red link on this node to the left */
nuclear@0 464 static struct rbnode *move_red_left(struct rbnode *tree)
nuclear@0 465 {
nuclear@0 466 /* flipping it makes both children go red, so we have a red to the left */
nuclear@0 467 color_flip(tree);
nuclear@0 468
nuclear@0 469 /* if after the flip we've got a red-red on the right-left, fix it */
nuclear@0 470 if(is_red(tree->right->left)) {
nuclear@0 471 tree->right = rot_right(tree->right);
nuclear@0 472 tree = rot_left(tree);
nuclear@0 473 color_flip(tree);
nuclear@0 474 }
nuclear@0 475 return tree;
nuclear@0 476 }
nuclear@0 477
nuclear@0 478 static struct rbnode *fix_up(struct rbnode *tree)
nuclear@0 479 {
nuclear@0 480 /* fix right-leaning */
nuclear@0 481 if(is_red(tree->right)) {
nuclear@0 482 tree = rot_left(tree);
nuclear@0 483 }
nuclear@0 484 /* change invalid red-red pairs into a proper 4-node */
nuclear@0 485 if(is_red(tree->left) && is_red(tree->left->left)) {
nuclear@0 486 tree = rot_right(tree);
nuclear@0 487 }
nuclear@0 488 /* split 4-nodes */
nuclear@0 489 if(is_red(tree->left) && is_red(tree->right)) {
nuclear@0 490 color_flip(tree);
nuclear@0 491 }
nuclear@0 492 return tree;
nuclear@0 493 }