1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/vr/rbtree.c	Fri Aug 22 16:55:16 2014 +0300
     1.3 @@ -0,0 +1,501 @@
     1.4 +/*
     1.5 +rbtree - simple balanced binary search tree (red-black tree) library.
     1.6 +Copyright (C) 2011-2014  John Tsiombikas <nuclear@member.fsf.org>
     1.7 +
     1.8 +rbtree is free software, feel free to use, modify, and redistribute it, under
     1.9 +the terms of the 3-clause BSD license. See COPYING for details.
    1.10 + */
    1.11 +#include <stdio.h>
    1.12 +#include <stdlib.h>
    1.13 +#include <stdint.h>
    1.14 +#include <string.h>
    1.15 +#include "rbtree.h"
    1.16 +
    1.17 +#define INT2PTR(x)	((void*)(intptr_t)(x))
    1.18 +#define PTR2INT(x)	((int)(intptr_t)(x))
    1.19 +
    1.20 +struct rbtree {
    1.21 +	struct rbnode *root;
    1.22 +
    1.23 +	rb_alloc_func_t alloc;
    1.24 +	rb_free_func_t free;
    1.25 +
    1.26 +	rb_cmp_func_t cmp;
    1.27 +	rb_del_func_t del;
    1.28 +	void *del_cls;
    1.29 +
    1.30 +	struct rbnode *rstack, *iter;
    1.31 +};
    1.32 +
    1.33 +static int cmpaddr(const void *ap, const void *bp);
    1.34 +static int cmpint(const void *ap, const void *bp);
    1.35 +
    1.36 +static int count_nodes(struct rbnode *node);
    1.37 +static void del_tree(struct rbnode *node, void (*delfunc)(struct rbnode*, void*), void *cls);
    1.38 +static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data);
    1.39 +static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key);
    1.40 +/*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key);*/
    1.41 +static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls);
    1.42 +
    1.43 +struct rbtree *rb_create(rb_cmp_func_t cmp_func)
    1.44 +{
    1.45 +	struct rbtree *rb;
    1.46 +
    1.47 +	if(!(rb = malloc(sizeof *rb))) {
    1.48 +		return 0;
    1.49 +	}
    1.50 +	if(rb_init(rb, cmp_func) == -1) {
    1.51 +		free(rb);
    1.52 +		return 0;
    1.53 +	}
    1.54 +	return rb;
    1.55 +}
    1.56 +
    1.57 +void rb_free(struct rbtree *rb)
    1.58 +{
    1.59 +	rb_destroy(rb);
    1.60 +	free(rb);
    1.61 +}
    1.62 +
    1.63 +
    1.64 +int rb_init(struct rbtree *rb, rb_cmp_func_t cmp_func)
    1.65 +{
    1.66 +	memset(rb, 0, sizeof *rb);
    1.67 +
    1.68 +	if(cmp_func == RB_KEY_INT) {
    1.69 +		rb->cmp = cmpint;
    1.70 +	} else if(cmp_func == RB_KEY_STRING) {
    1.71 +		rb->cmp = (rb_cmp_func_t)strcmp;
    1.72 +	} else {
    1.73 +		rb->cmp = cmpaddr;
    1.74 +	}
    1.75 +
    1.76 +	rb->alloc = malloc;
    1.77 +	rb->free = free;
    1.78 +	return 0;
    1.79 +}
    1.80 +
    1.81 +void rb_destroy(struct rbtree *rb)
    1.82 +{
    1.83 +	del_tree(rb->root, rb->del, rb->del_cls);
    1.84 +}
    1.85 +
    1.86 +void rb_set_allocator(struct rbtree *rb, rb_alloc_func_t alloc, rb_free_func_t free)
    1.87 +{
    1.88 +	rb->alloc = alloc;
    1.89 +	rb->free = free;
    1.90 +}
    1.91 +
    1.92 +
    1.93 +void rb_set_compare_func(struct rbtree *rb, rb_cmp_func_t func)
    1.94 +{
    1.95 +	rb->cmp = func;
    1.96 +}
    1.97 +
    1.98 +void rb_set_delete_func(struct rbtree *rb, rb_del_func_t func, void *cls)
    1.99 +{
   1.100 +	rb->del = func;
   1.101 +	rb->del_cls = cls;
   1.102 +}
   1.103 +
   1.104 +
   1.105 +void rb_clear(struct rbtree *rb)
   1.106 +{
   1.107 +	del_tree(rb->root, rb->del, rb->del_cls);
   1.108 +	rb->root = 0;
   1.109 +}
   1.110 +
   1.111 +int rb_copy(struct rbtree *dest, struct rbtree *src)
   1.112 +{
   1.113 +	struct rbnode *node;
   1.114 +
   1.115 +	rb_clear(dest);
   1.116 +	rb_begin(src);
   1.117 +	while((node = rb_next(src))) {
   1.118 +		if(rb_insert(dest, node->key, node->data) == -1) {
   1.119 +			return -1;
   1.120 +		}
   1.121 +	}
   1.122 +	return 0;
   1.123 +}
   1.124 +
   1.125 +int rb_size(struct rbtree *rb)
   1.126 +{
   1.127 +	return count_nodes(rb->root);
   1.128 +}
   1.129 +
   1.130 +int rb_insert(struct rbtree *rb, void *key, void *data)
   1.131 +{
   1.132 +	rb->root = insert(rb, rb->root, key, data);
   1.133 +	rb->root->red = 0;
   1.134 +	return 0;
   1.135 +}
   1.136 +
   1.137 +int rb_inserti(struct rbtree *rb, int key, void *data)
   1.138 +{
   1.139 +	rb->root = insert(rb, rb->root, INT2PTR(key), data);
   1.140 +	rb->root->red = 0;
   1.141 +	return 0;
   1.142 +}
   1.143 +
   1.144 +
   1.145 +int rb_delete(struct rbtree *rb, void *key)
   1.146 +{
   1.147 +	rb->root = delete(rb, rb->root, key);
   1.148 +	rb->root->red = 0;
   1.149 +	return 0;
   1.150 +}
   1.151 +
   1.152 +int rb_deletei(struct rbtree *rb, int key)
   1.153 +{
   1.154 +	rb->root = delete(rb, rb->root, INT2PTR(key));
   1.155 +	rb->root->red = 0;
   1.156 +	return 0;
   1.157 +}
   1.158 +
   1.159 +
   1.160 +void *rb_find(struct rbtree *rb, void *key)
   1.161 +{
   1.162 +	struct rbnode *node = rb->root;
   1.163 +
   1.164 +	while(node) {
   1.165 +		int cmp = rb->cmp(key, node->key);
   1.166 +		if(cmp == 0) {
   1.167 +			return node->data;
   1.168 +		}
   1.169 +		node = cmp < 0 ? node->left : node->right;
   1.170 +	}
   1.171 +	return 0;
   1.172 +}
   1.173 +
   1.174 +void *rb_findi(struct rbtree *rb, int key)
   1.175 +{
   1.176 +	return rb_find(rb, INT2PTR(key));
   1.177 +}
   1.178 +
   1.179 +
   1.180 +void rb_foreach(struct rbtree *rb, void (*func)(struct rbnode*, void*), void *cls)
   1.181 +{
   1.182 +	traverse(rb->root, func, cls);
   1.183 +}
   1.184 +
   1.185 +
   1.186 +struct rbnode *rb_root(struct rbtree *rb)
   1.187 +{
   1.188 +	return rb->root;
   1.189 +}
   1.190 +
   1.191 +void rb_begin(struct rbtree *rb)
   1.192 +{
   1.193 +	rb->rstack = 0;
   1.194 +	rb->iter = rb->root;
   1.195 +}
   1.196 +
   1.197 +#define push(sp, x)		((x)->next = (sp), (sp) = (x))
   1.198 +#define pop(sp)			((sp) = (sp)->next)
   1.199 +#define top(sp)			(sp)
   1.200 +
   1.201 +struct rbnode *rb_next(struct rbtree *rb)
   1.202 +{
   1.203 +	struct rbnode *res = 0;
   1.204 +
   1.205 +	while(rb->rstack || rb->iter) {
   1.206 +		if(rb->iter) {
   1.207 +			push(rb->rstack, rb->iter);
   1.208 +			rb->iter = rb->iter->left;
   1.209 +		} else {
   1.210 +			rb->iter = top(rb->rstack);
   1.211 +			pop(rb->rstack);
   1.212 +			res = rb->iter;
   1.213 +			rb->iter = rb->iter->right;
   1.214 +			break;
   1.215 +		}
   1.216 +	}
   1.217 +	return res;
   1.218 +}
   1.219 +
   1.220 +void *rb_node_key(struct rbnode *node)
   1.221 +{
   1.222 +	return node ? node->key : 0;
   1.223 +}
   1.224 +
   1.225 +int rb_node_keyi(struct rbnode *node)
   1.226 +{
   1.227 +	return node ? PTR2INT(node->key) : 0;
   1.228 +}
   1.229 +
   1.230 +void *rb_node_data(struct rbnode *node)
   1.231 +{
   1.232 +	return node ? node->data : 0;
   1.233 +}
   1.234 +
   1.235 +static int cmpaddr(const void *ap, const void *bp)
   1.236 +{
   1.237 +	return ap < bp ? -1 : (ap > bp ? 1 : 0);
   1.238 +}
   1.239 +
   1.240 +static int cmpint(const void *ap, const void *bp)
   1.241 +{
   1.242 +	return PTR2INT(ap) - PTR2INT(bp);
   1.243 +}
   1.244 +
   1.245 +
   1.246 +/* ---- left-leaning 2-3 red-black implementation ---- */
   1.247 +
   1.248 +/* helper prototypes */
   1.249 +static int is_red(struct rbnode *tree);
   1.250 +static void color_flip(struct rbnode *tree);
   1.251 +static struct rbnode *rot_left(struct rbnode *a);
   1.252 +static struct rbnode *rot_right(struct rbnode *a);
   1.253 +static struct rbnode *find_min(struct rbnode *tree);
   1.254 +static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree);
   1.255 +/*static struct rbnode *move_red_right(struct rbnode *tree);*/
   1.256 +static struct rbnode *move_red_left(struct rbnode *tree);
   1.257 +static struct rbnode *fix_up(struct rbnode *tree);
   1.258 +
   1.259 +static int count_nodes(struct rbnode *node)
   1.260 +{
   1.261 +	if(!node)
   1.262 +		return 0;
   1.263 +
   1.264 +	return 1 + count_nodes(node->left) + count_nodes(node->right);
   1.265 +}
   1.266 +
   1.267 +static void del_tree(struct rbnode *node, rb_del_func_t delfunc, void *cls)
   1.268 +{
   1.269 +	if(!node)
   1.270 +		return;
   1.271 +
   1.272 +	del_tree(node->left, delfunc, cls);
   1.273 +	del_tree(node->right, delfunc, cls);
   1.274 +
   1.275 +	if(delfunc) {
   1.276 +		delfunc(node, cls);
   1.277 +	}
   1.278 +	free(node);
   1.279 +}
   1.280 +
   1.281 +static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data)
   1.282 +{
   1.283 +	int cmp;
   1.284 +
   1.285 +	if(!tree) {
   1.286 +		struct rbnode *node = rb->alloc(sizeof *node);
   1.287 +		node->red = 1;
   1.288 +		node->key = key;
   1.289 +		node->data = data;
   1.290 +		node->left = node->right = 0;
   1.291 +		return node;
   1.292 +	}
   1.293 +
   1.294 +	cmp = rb->cmp(key, tree->key);
   1.295 +
   1.296 +	if(cmp < 0) {
   1.297 +		tree->left = insert(rb, tree->left, key, data);
   1.298 +	} else if(cmp > 0) {
   1.299 +		tree->right = insert(rb, tree->right, key, data);
   1.300 +	} else {
   1.301 +		tree->data = data;
   1.302 +	}
   1.303 +
   1.304 +	/* fix right-leaning reds */
   1.305 +	if(is_red(tree->right)) {
   1.306 +		tree = rot_left(tree);
   1.307 +	}
   1.308 +	/* fix two reds in a row */
   1.309 +	if(is_red(tree->left) && is_red(tree->left->left)) {
   1.310 +		tree = rot_right(tree);
   1.311 +	}
   1.312 +
   1.313 +	/* if 4-node, split it by color inversion */
   1.314 +	if(is_red(tree->left) && is_red(tree->right)) {
   1.315 +		color_flip(tree);
   1.316 +	}
   1.317 +
   1.318 +	return tree;
   1.319 +}
   1.320 +
   1.321 +static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key)
   1.322 +{
   1.323 +	int cmp;
   1.324 +
   1.325 +	if(!tree) {
   1.326 +		return 0;
   1.327 +	}
   1.328 +
   1.329 +	cmp = rb->cmp(key, tree->key);
   1.330 +
   1.331 +	if(cmp < 0) {
   1.332 +		if(!is_red(tree->left) && !is_red(tree->left->left)) {
   1.333 +			tree = move_red_left(tree);
   1.334 +		}
   1.335 +		tree->left = delete(rb, tree->left, key);
   1.336 +	} else {
   1.337 +		/* need reds on the right */
   1.338 +		if(is_red(tree->left)) {
   1.339 +			tree = rot_right(tree);
   1.340 +		}
   1.341 +
   1.342 +		/* found it at the bottom (XXX what certifies left is null?) */
   1.343 +		if(cmp == 0 && !tree->right) {
   1.344 +			if(rb->del) {
   1.345 +				rb->del(tree, rb->del_cls);
   1.346 +			}
   1.347 +			rb->free(tree);
   1.348 +			return 0;
   1.349 +		}
   1.350 +
   1.351 +		if(!is_red(tree->right) && !is_red(tree->right->left)) {
   1.352 +			tree = move_red_left(tree);
   1.353 +		}
   1.354 +
   1.355 +		if(key == tree->key) {
   1.356 +			struct rbnode *rmin = find_min(tree->right);
   1.357 +			tree->key = rmin->key;
   1.358 +			tree->data = rmin->data;
   1.359 +			tree->right = del_min(rb, tree->right);
   1.360 +		} else {
   1.361 +			tree->right = delete(rb, tree->right, key);
   1.362 +		}
   1.363 +	}
   1.364 +
   1.365 +	return fix_up(tree);
   1.366 +}
   1.367 +
   1.368 +/*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key)
   1.369 +{
   1.370 +	int cmp;
   1.371 +
   1.372 +	if(!node)
   1.373 +		return 0;
   1.374 +
   1.375 +	if((cmp = rb->cmp(key, node->key)) == 0) {
   1.376 +		return node;
   1.377 +	}
   1.378 +	return find(rb, cmp < 0 ? node->left : node->right, key);
   1.379 +}*/
   1.380 +
   1.381 +static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls)
   1.382 +{
   1.383 +	if(!node)
   1.384 +		return;
   1.385 +
   1.386 +	traverse(node->left, func, cls);
   1.387 +	func(node, cls);
   1.388 +	traverse(node->right, func, cls);
   1.389 +}
   1.390 +
   1.391 +/* helpers */
   1.392 +
   1.393 +static int is_red(struct rbnode *tree)
   1.394 +{
   1.395 +	return tree && tree->red;
   1.396 +}
   1.397 +
   1.398 +static void color_flip(struct rbnode *tree)
   1.399 +{
   1.400 +	tree->red = !tree->red;
   1.401 +	tree->left->red = !tree->left->red;
   1.402 +	tree->right->red = !tree->right->red;
   1.403 +}
   1.404 +
   1.405 +static struct rbnode *rot_left(struct rbnode *a)
   1.406 +{
   1.407 +	struct rbnode *b = a->right;
   1.408 +	a->right = b->left;
   1.409 +	b->left = a;
   1.410 +	b->red = a->red;
   1.411 +	a->red = 1;
   1.412 +	return b;
   1.413 +}
   1.414 +
   1.415 +static struct rbnode *rot_right(struct rbnode *a)
   1.416 +{
   1.417 +	struct rbnode *b = a->left;
   1.418 +	a->left = b->right;
   1.419 +	b->right = a;
   1.420 +	b->red = a->red;
   1.421 +	a->red = 1;
   1.422 +	return b;
   1.423 +}
   1.424 +
   1.425 +static struct rbnode *find_min(struct rbnode *tree)
   1.426 +{
   1.427 +	struct rbnode *node = tree;
   1.428 +
   1.429 +	if(!tree)
   1.430 +		return 0;
   1.431 +
   1.432 +	while(node->left) {
   1.433 +		node = node->left;
   1.434 +	}
   1.435 +	return node;
   1.436 +}
   1.437 +
   1.438 +static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree)
   1.439 +{
   1.440 +	if(!tree->left) {
   1.441 +		if(rb->del) {
   1.442 +			rb->del(tree->left, rb->del_cls);
   1.443 +		}
   1.444 +		rb->free(tree->left);
   1.445 +		return 0;
   1.446 +	}
   1.447 +
   1.448 +	/* make sure we've got red (3/4-nodes) at the left side so we can delete at the bottom */
   1.449 +	if(!is_red(tree->left) && !is_red(tree->left->left)) {
   1.450 +		tree = move_red_left(tree);
   1.451 +	}
   1.452 +	tree->left = del_min(rb, tree->left);
   1.453 +
   1.454 +	/* fix right-reds, red-reds, and split 4-nodes on the way up */
   1.455 +	return fix_up(tree);
   1.456 +}
   1.457 +
   1.458 +#if 0
   1.459 +/* push a red link on this node to the right */
   1.460 +static struct rbnode *move_red_right(struct rbnode *tree)
   1.461 +{
   1.462 +	/* flipping it makes both children go red, so we have a red to the right */
   1.463 +	color_flip(tree);
   1.464 +
   1.465 +	/* if after the flip we've got a red-red situation to the left, fix it */
   1.466 +	if(is_red(tree->left->left)) {
   1.467 +		tree = rot_right(tree);
   1.468 +		color_flip(tree);
   1.469 +	}
   1.470 +	return tree;
   1.471 +}
   1.472 +#endif
   1.473 +
   1.474 +/* push a red link on this node to the left */
   1.475 +static struct rbnode *move_red_left(struct rbnode *tree)
   1.476 +{
   1.477 +	/* flipping it makes both children go red, so we have a red to the left */
   1.478 +	color_flip(tree);
   1.479 +
   1.480 +	/* if after the flip we've got a red-red on the right-left, fix it */
   1.481 +	if(is_red(tree->right->left)) {
   1.482 +		tree->right = rot_right(tree->right);
   1.483 +		tree = rot_left(tree);
   1.484 +		color_flip(tree);
   1.485 +	}
   1.486 +	return tree;
   1.487 +}
   1.488 +
   1.489 +static struct rbnode *fix_up(struct rbnode *tree)
   1.490 +{
   1.491 +	/* fix right-leaning */
   1.492 +	if(is_red(tree->right)) {
   1.493 +		tree = rot_left(tree);
   1.494 +	}
   1.495 +	/* change invalid red-red pairs into a proper 4-node */
   1.496 +	if(is_red(tree->left) && is_red(tree->left->left)) {
   1.497 +		tree = rot_right(tree);
   1.498 +	}
   1.499 +	/* split 4-nodes */
   1.500 +	if(is_red(tree->left) && is_red(tree->right)) {
   1.501 +		color_flip(tree);
   1.502 +	}
   1.503 +	return tree;
   1.504 +}