nuclear@6: /*
nuclear@6: rbtree - simple balanced binary search tree (red-black tree) library.
nuclear@6: Copyright (C) 2011-2014  John Tsiombikas <nuclear@member.fsf.org>
nuclear@6: 
nuclear@6: rbtree is free software, feel free to use, modify, and redistribute it, under
nuclear@6: the terms of the 3-clause BSD license. See COPYING for details.
nuclear@6:  */
nuclear@6: #include <stdio.h>
nuclear@6: #include <stdlib.h>
nuclear@6: #include <stdint.h>
nuclear@6: #include <string.h>
nuclear@6: #include "rbtree.h"
nuclear@6: 
nuclear@6: #define INT2PTR(x)	((void*)(intptr_t)(x))
nuclear@6: #define PTR2INT(x)	((int)(intptr_t)(x))
nuclear@6: 
nuclear@6: struct rbtree {
nuclear@6: 	struct rbnode *root;
nuclear@6: 
nuclear@6: 	rb_alloc_func_t alloc;
nuclear@6: 	rb_free_func_t free;
nuclear@6: 
nuclear@6: 	rb_cmp_func_t cmp;
nuclear@6: 	rb_del_func_t del;
nuclear@6: 	void *del_cls;
nuclear@6: 
nuclear@6: 	struct rbnode *rstack, *iter;
nuclear@6: };
nuclear@6: 
nuclear@6: static int cmpaddr(const void *ap, const void *bp);
nuclear@6: static int cmpint(const void *ap, const void *bp);
nuclear@6: 
nuclear@6: static int count_nodes(struct rbnode *node);
nuclear@6: static void del_tree(struct rbnode *node, void (*delfunc)(struct rbnode*, void*), void *cls);
nuclear@6: static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data);
nuclear@6: static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key);
nuclear@6: /*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key);*/
nuclear@6: static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls);
nuclear@6: 
nuclear@6: struct rbtree *rb_create(rb_cmp_func_t cmp_func)
nuclear@6: {
nuclear@6: 	struct rbtree *rb;
nuclear@6: 
nuclear@6: 	if(!(rb = malloc(sizeof *rb))) {
nuclear@6: 		return 0;
nuclear@6: 	}
nuclear@6: 	if(rb_init(rb, cmp_func) == -1) {
nuclear@6: 		free(rb);
nuclear@6: 		return 0;
nuclear@6: 	}
nuclear@6: 	return rb;
nuclear@6: }
nuclear@6: 
nuclear@6: void rb_free(struct rbtree *rb)
nuclear@6: {
nuclear@6: 	rb_destroy(rb);
nuclear@6: 	free(rb);
nuclear@6: }
nuclear@6: 
nuclear@6: 
nuclear@6: int rb_init(struct rbtree *rb, rb_cmp_func_t cmp_func)
nuclear@6: {
nuclear@6: 	memset(rb, 0, sizeof *rb);
nuclear@6: 
nuclear@6: 	if(!cmp_func) {
nuclear@6: 		rb->cmp = cmpaddr;
nuclear@6: 	} else if(cmp_func == RB_KEY_INT) {
nuclear@6: 		rb->cmp = cmpint;
nuclear@6: 	} else if(cmp_func == RB_KEY_STRING) {
nuclear@6: 		rb->cmp = (rb_cmp_func_t)strcmp;
nuclear@6: 	} else {
nuclear@6: 		rb->cmp = cmp_func;
nuclear@6: 	}
nuclear@6: 
nuclear@6: 	rb->alloc = malloc;
nuclear@6: 	rb->free = free;
nuclear@6: 	return 0;
nuclear@6: }
nuclear@6: 
nuclear@6: void rb_destroy(struct rbtree *rb)
nuclear@6: {
nuclear@6: 	del_tree(rb->root, rb->del, rb->del_cls);
nuclear@6: }
nuclear@6: 
nuclear@6: void rb_set_allocator(struct rbtree *rb, rb_alloc_func_t alloc, rb_free_func_t free)
nuclear@6: {
nuclear@6: 	rb->alloc = alloc;
nuclear@6: 	rb->free = free;
nuclear@6: }
nuclear@6: 
nuclear@6: 
nuclear@6: void rb_set_compare_func(struct rbtree *rb, rb_cmp_func_t func)
nuclear@6: {
nuclear@6: 	rb->cmp = func;
nuclear@6: }
nuclear@6: 
nuclear@6: void rb_set_delete_func(struct rbtree *rb, rb_del_func_t func, void *cls)
nuclear@6: {
nuclear@6: 	rb->del = func;
nuclear@6: 	rb->del_cls = cls;
nuclear@6: }
nuclear@6: 
nuclear@6: 
nuclear@6: void rb_clear(struct rbtree *rb)
nuclear@6: {
nuclear@6: 	del_tree(rb->root, rb->del, rb->del_cls);
nuclear@6: 	rb->root = 0;
nuclear@6: }
nuclear@6: 
nuclear@6: int rb_copy(struct rbtree *dest, struct rbtree *src)
nuclear@6: {
nuclear@6: 	struct rbnode *node;
nuclear@6: 
nuclear@6: 	rb_clear(dest);
nuclear@6: 	rb_begin(src);
nuclear@6: 	while((node = rb_next(src))) {
nuclear@6: 		if(rb_insert(dest, node->key, node->data) == -1) {
nuclear@6: 			return -1;
nuclear@6: 		}
nuclear@6: 	}
nuclear@6: 	return 0;
nuclear@6: }
nuclear@6: 
nuclear@6: int rb_size(struct rbtree *rb)
nuclear@6: {
nuclear@6: 	return count_nodes(rb->root);
nuclear@6: }
nuclear@6: 
nuclear@6: int rb_insert(struct rbtree *rb, void *key, void *data)
nuclear@6: {
nuclear@6: 	rb->root = insert(rb, rb->root, key, data);
nuclear@6: 	rb->root->red = 0;
nuclear@6: 	return 0;
nuclear@6: }
nuclear@6: 
nuclear@6: int rb_inserti(struct rbtree *rb, int key, void *data)
nuclear@6: {
nuclear@6: 	rb->root = insert(rb, rb->root, INT2PTR(key), data);
nuclear@6: 	rb->root->red = 0;
nuclear@6: 	return 0;
nuclear@6: }
nuclear@6: 
nuclear@6: 
nuclear@6: int rb_delete(struct rbtree *rb, void *key)
nuclear@6: {
nuclear@6: 	rb->root = delete(rb, rb->root, key);
nuclear@6: 	rb->root->red = 0;
nuclear@6: 	return 0;
nuclear@6: }
nuclear@6: 
nuclear@6: int rb_deletei(struct rbtree *rb, int key)
nuclear@6: {
nuclear@6: 	rb->root = delete(rb, rb->root, INT2PTR(key));
nuclear@6: 	rb->root->red = 0;
nuclear@6: 	return 0;
nuclear@6: }
nuclear@6: 
nuclear@6: 
nuclear@6: struct rbnode *rb_find(struct rbtree *rb, void *key)
nuclear@6: {
nuclear@6: 	struct rbnode *node = rb->root;
nuclear@6: 
nuclear@6: 	while(node) {
nuclear@6: 		int cmp = rb->cmp(key, node->key);
nuclear@6: 		if(cmp == 0) {
nuclear@6: 			return node;
nuclear@6: 		}
nuclear@6: 		node = cmp < 0 ? node->left : node->right;
nuclear@6: 	}
nuclear@6: 	return 0;
nuclear@6: }
nuclear@6: 
nuclear@6: struct rbnode *rb_findi(struct rbtree *rb, int key)
nuclear@6: {
nuclear@6: 	return rb_find(rb, INT2PTR(key));
nuclear@6: }
nuclear@6: 
nuclear@6: 
nuclear@6: void rb_foreach(struct rbtree *rb, void (*func)(struct rbnode*, void*), void *cls)
nuclear@6: {
nuclear@6: 	traverse(rb->root, func, cls);
nuclear@6: }
nuclear@6: 
nuclear@6: 
nuclear@6: struct rbnode *rb_root(struct rbtree *rb)
nuclear@6: {
nuclear@6: 	return rb->root;
nuclear@6: }
nuclear@6: 
nuclear@6: void rb_begin(struct rbtree *rb)
nuclear@6: {
nuclear@6: 	rb->rstack = 0;
nuclear@6: 	rb->iter = rb->root;
nuclear@6: }
nuclear@6: 
nuclear@6: #define push(sp, x)		((x)->next = (sp), (sp) = (x))
nuclear@6: #define pop(sp)			((sp) = (sp)->next)
nuclear@6: #define top(sp)			(sp)
nuclear@6: 
nuclear@6: struct rbnode *rb_next(struct rbtree *rb)
nuclear@6: {
nuclear@6: 	struct rbnode *res = 0;
nuclear@6: 
nuclear@6: 	while(rb->rstack || rb->iter) {
nuclear@6: 		if(rb->iter) {
nuclear@6: 			push(rb->rstack, rb->iter);
nuclear@6: 			rb->iter = rb->iter->left;
nuclear@6: 		} else {
nuclear@6: 			rb->iter = top(rb->rstack);
nuclear@6: 			pop(rb->rstack);
nuclear@6: 			res = rb->iter;
nuclear@6: 			rb->iter = rb->iter->right;
nuclear@6: 			break;
nuclear@6: 		}
nuclear@6: 	}
nuclear@6: 	return res;
nuclear@6: }
nuclear@6: 
nuclear@6: void *rb_node_key(struct rbnode *node)
nuclear@6: {
nuclear@6: 	return node ? node->key : 0;
nuclear@6: }
nuclear@6: 
nuclear@6: int rb_node_keyi(struct rbnode *node)
nuclear@6: {
nuclear@6: 	return node ? PTR2INT(node->key) : 0;
nuclear@6: }
nuclear@6: 
nuclear@6: void *rb_node_data(struct rbnode *node)
nuclear@6: {
nuclear@6: 	return node ? node->data : 0;
nuclear@6: }
nuclear@6: 
nuclear@6: static int cmpaddr(const void *ap, const void *bp)
nuclear@6: {
nuclear@6: 	return ap < bp ? -1 : (ap > bp ? 1 : 0);
nuclear@6: }
nuclear@6: 
nuclear@6: static int cmpint(const void *ap, const void *bp)
nuclear@6: {
nuclear@6: 	return PTR2INT(ap) - PTR2INT(bp);
nuclear@6: }
nuclear@6: 
nuclear@6: 
nuclear@6: /* ---- left-leaning 2-3 red-black implementation ---- */
nuclear@6: 
nuclear@6: /* helper prototypes */
nuclear@6: static int is_red(struct rbnode *tree);
nuclear@6: static void color_flip(struct rbnode *tree);
nuclear@6: static struct rbnode *rot_left(struct rbnode *a);
nuclear@6: static struct rbnode *rot_right(struct rbnode *a);
nuclear@6: static struct rbnode *find_min(struct rbnode *tree);
nuclear@6: static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree);
nuclear@6: /*static struct rbnode *move_red_right(struct rbnode *tree);*/
nuclear@6: static struct rbnode *move_red_left(struct rbnode *tree);
nuclear@6: static struct rbnode *fix_up(struct rbnode *tree);
nuclear@6: 
nuclear@6: static int count_nodes(struct rbnode *node)
nuclear@6: {
nuclear@6: 	if(!node)
nuclear@6: 		return 0;
nuclear@6: 
nuclear@6: 	return 1 + count_nodes(node->left) + count_nodes(node->right);
nuclear@6: }
nuclear@6: 
nuclear@6: static void del_tree(struct rbnode *node, rb_del_func_t delfunc, void *cls)
nuclear@6: {
nuclear@6: 	if(!node)
nuclear@6: 		return;
nuclear@6: 
nuclear@6: 	del_tree(node->left, delfunc, cls);
nuclear@6: 	del_tree(node->right, delfunc, cls);
nuclear@6: 
nuclear@6: 	if(delfunc) {
nuclear@6: 		delfunc(node, cls);
nuclear@6: 	}
nuclear@6: 	free(node);
nuclear@6: }
nuclear@6: 
nuclear@6: static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data)
nuclear@6: {
nuclear@6: 	int cmp;
nuclear@6: 
nuclear@6: 	if(!tree) {
nuclear@6: 		struct rbnode *node = rb->alloc(sizeof *node);
nuclear@6: 		node->red = 1;
nuclear@6: 		node->key = key;
nuclear@6: 		node->data = data;
nuclear@6: 		node->left = node->right = 0;
nuclear@6: 		return node;
nuclear@6: 	}
nuclear@6: 
nuclear@6: 	cmp = rb->cmp(key, tree->key);
nuclear@6: 
nuclear@6: 	if(cmp < 0) {
nuclear@6: 		tree->left = insert(rb, tree->left, key, data);
nuclear@6: 	} else if(cmp > 0) {
nuclear@6: 		tree->right = insert(rb, tree->right, key, data);
nuclear@6: 	} else {
nuclear@6: 		tree->data = data;
nuclear@6: 	}
nuclear@6: 
nuclear@6: 	/* fix right-leaning reds */
nuclear@6: 	if(is_red(tree->right)) {
nuclear@6: 		tree = rot_left(tree);
nuclear@6: 	}
nuclear@6: 	/* fix two reds in a row */
nuclear@6: 	if(is_red(tree->left) && is_red(tree->left->left)) {
nuclear@6: 		tree = rot_right(tree);
nuclear@6: 	}
nuclear@6: 
nuclear@6: 	/* if 4-node, split it by color inversion */
nuclear@6: 	if(is_red(tree->left) && is_red(tree->right)) {
nuclear@6: 		color_flip(tree);
nuclear@6: 	}
nuclear@6: 
nuclear@6: 	return tree;
nuclear@6: }
nuclear@6: 
nuclear@6: static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key)
nuclear@6: {
nuclear@6: 	int cmp;
nuclear@6: 
nuclear@6: 	if(!tree) {
nuclear@6: 		return 0;
nuclear@6: 	}
nuclear@6: 
nuclear@6: 	cmp = rb->cmp(key, tree->key);
nuclear@6: 
nuclear@6: 	if(cmp < 0) {
nuclear@6: 		if(!is_red(tree->left) && !is_red(tree->left->left)) {
nuclear@6: 			tree = move_red_left(tree);
nuclear@6: 		}
nuclear@6: 		tree->left = delete(rb, tree->left, key);
nuclear@6: 	} else {
nuclear@6: 		/* need reds on the right */
nuclear@6: 		if(is_red(tree->left)) {
nuclear@6: 			tree = rot_right(tree);
nuclear@6: 		}
nuclear@6: 
nuclear@6: 		/* found it at the bottom (XXX what certifies left is null?) */
nuclear@6: 		if(cmp == 0 && !tree->right) {
nuclear@6: 			if(rb->del) {
nuclear@6: 				rb->del(tree, rb->del_cls);
nuclear@6: 			}
nuclear@6: 			rb->free(tree);
nuclear@6: 			return 0;
nuclear@6: 		}
nuclear@6: 
nuclear@6: 		if(!is_red(tree->right) && !is_red(tree->right->left)) {
nuclear@6: 			tree = move_red_left(tree);
nuclear@6: 		}
nuclear@6: 
nuclear@6: 		if(key == tree->key) {
nuclear@6: 			struct rbnode *rmin = find_min(tree->right);
nuclear@6: 			tree->key = rmin->key;
nuclear@6: 			tree->data = rmin->data;
nuclear@6: 			tree->right = del_min(rb, tree->right);
nuclear@6: 		} else {
nuclear@6: 			tree->right = delete(rb, tree->right, key);
nuclear@6: 		}
nuclear@6: 	}
nuclear@6: 
nuclear@6: 	return fix_up(tree);
nuclear@6: }
nuclear@6: 
nuclear@6: /*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key)
nuclear@6: {
nuclear@6: 	int cmp;
nuclear@6: 
nuclear@6: 	if(!node)
nuclear@6: 		return 0;
nuclear@6: 
nuclear@6: 	if((cmp = rb->cmp(key, node->key)) == 0) {
nuclear@6: 		return node;
nuclear@6: 	}
nuclear@6: 	return find(rb, cmp < 0 ? node->left : node->right, key);
nuclear@6: }*/
nuclear@6: 
nuclear@6: static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls)
nuclear@6: {
nuclear@6: 	if(!node)
nuclear@6: 		return;
nuclear@6: 
nuclear@6: 	traverse(node->left, func, cls);
nuclear@6: 	func(node, cls);
nuclear@6: 	traverse(node->right, func, cls);
nuclear@6: }
nuclear@6: 
nuclear@6: /* helpers */
nuclear@6: 
nuclear@6: static int is_red(struct rbnode *tree)
nuclear@6: {
nuclear@6: 	return tree && tree->red;
nuclear@6: }
nuclear@6: 
nuclear@6: static void color_flip(struct rbnode *tree)
nuclear@6: {
nuclear@6: 	tree->red = !tree->red;
nuclear@6: 	tree->left->red = !tree->left->red;
nuclear@6: 	tree->right->red = !tree->right->red;
nuclear@6: }
nuclear@6: 
nuclear@6: static struct rbnode *rot_left(struct rbnode *a)
nuclear@6: {
nuclear@6: 	struct rbnode *b = a->right;
nuclear@6: 	a->right = b->left;
nuclear@6: 	b->left = a;
nuclear@6: 	b->red = a->red;
nuclear@6: 	a->red = 1;
nuclear@6: 	return b;
nuclear@6: }
nuclear@6: 
nuclear@6: static struct rbnode *rot_right(struct rbnode *a)
nuclear@6: {
nuclear@6: 	struct rbnode *b = a->left;
nuclear@6: 	a->left = b->right;
nuclear@6: 	b->right = a;
nuclear@6: 	b->red = a->red;
nuclear@6: 	a->red = 1;
nuclear@6: 	return b;
nuclear@6: }
nuclear@6: 
nuclear@6: static struct rbnode *find_min(struct rbnode *tree)
nuclear@6: {
nuclear@6: 	if(!tree)
nuclear@6: 		return 0;
nuclear@6: 
nuclear@6: 	while(tree->left) {
nuclear@6: 		tree = tree->left;
nuclear@6: 	}
nuclear@6: 	return tree;
nuclear@6: }
nuclear@6: 
nuclear@6: static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree)
nuclear@6: {
nuclear@6: 	if(!tree->left) {
nuclear@6: 		if(rb->del) {
nuclear@6: 			rb->del(tree->left, rb->del_cls);
nuclear@6: 		}
nuclear@6: 		rb->free(tree->left);
nuclear@6: 		return 0;
nuclear@6: 	}
nuclear@6: 
nuclear@6: 	/* make sure we've got red (3/4-nodes) at the left side so we can delete at the bottom */
nuclear@6: 	if(!is_red(tree->left) && !is_red(tree->left->left)) {
nuclear@6: 		tree = move_red_left(tree);
nuclear@6: 	}
nuclear@6: 	tree->left = del_min(rb, tree->left);
nuclear@6: 
nuclear@6: 	/* fix right-reds, red-reds, and split 4-nodes on the way up */
nuclear@6: 	return fix_up(tree);
nuclear@6: }
nuclear@6: 
nuclear@6: #if 0
nuclear@6: /* push a red link on this node to the right */
nuclear@6: static struct rbnode *move_red_right(struct rbnode *tree)
nuclear@6: {
nuclear@6: 	/* flipping it makes both children go red, so we have a red to the right */
nuclear@6: 	color_flip(tree);
nuclear@6: 
nuclear@6: 	/* if after the flip we've got a red-red situation to the left, fix it */
nuclear@6: 	if(is_red(tree->left->left)) {
nuclear@6: 		tree = rot_right(tree);
nuclear@6: 		color_flip(tree);
nuclear@6: 	}
nuclear@6: 	return tree;
nuclear@6: }
nuclear@6: #endif
nuclear@6: 
nuclear@6: /* push a red link on this node to the left */
nuclear@6: static struct rbnode *move_red_left(struct rbnode *tree)
nuclear@6: {
nuclear@6: 	/* flipping it makes both children go red, so we have a red to the left */
nuclear@6: 	color_flip(tree);
nuclear@6: 
nuclear@6: 	/* if after the flip we've got a red-red on the right-left, fix it */
nuclear@6: 	if(is_red(tree->right->left)) {
nuclear@6: 		tree->right = rot_right(tree->right);
nuclear@6: 		tree = rot_left(tree);
nuclear@6: 		color_flip(tree);
nuclear@6: 	}
nuclear@6: 	return tree;
nuclear@6: }
nuclear@6: 
nuclear@6: static struct rbnode *fix_up(struct rbnode *tree)
nuclear@6: {
nuclear@6: 	/* fix right-leaning */
nuclear@6: 	if(is_red(tree->right)) {
nuclear@6: 		tree = rot_left(tree);
nuclear@6: 	}
nuclear@6: 	/* change invalid red-red pairs into a proper 4-node */
nuclear@6: 	if(is_red(tree->left) && is_red(tree->left->left)) {
nuclear@6: 		tree = rot_right(tree);
nuclear@6: 	}
nuclear@6: 	/* split 4-nodes */
nuclear@6: 	if(is_red(tree->left) && is_red(tree->right)) {
nuclear@6: 		color_flip(tree);
nuclear@6: 	}
nuclear@6: 	return tree;
nuclear@6: }