godot/core/set.h
Rémi Verschelde a7f49ac9a1 Update copyright statements to 2020
Happy new year to the wonderful Godot community!

We're starting a new decade with a well-established, non-profit, free
and open source game engine, and tons of further improvements in the
pipeline from hundreds of contributors.

Godot will keep getting better, and we're looking forward to all the
games that the community will keep developing and releasing with it.
2020-01-01 11:16:22 +01:00

638 lines
14 KiB
C++

/*************************************************************************/
/* set.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#ifndef SET_H
#define SET_H
#include "core/os/memory.h"
#include "core/typedefs.h"
// based on the very nice implementation of rb-trees by:
// https://web.archive.org/web/20120507164830/http://web.mit.edu/~emin/www/source_code/red_black_tree/index.html
template <class T, class C = Comparator<T>, class A = DefaultAllocator>
class Set {
enum Color {
RED,
BLACK
};
struct _Data;
public:
class Element {
private:
friend class Set<T, C, A>;
int color;
Element *right;
Element *left;
Element *parent;
Element *_next;
Element *_prev;
T value;
//_Data *data;
public:
const Element *next() const {
return _next;
}
Element *next() {
return _next;
}
const Element *prev() const {
return _prev;
}
Element *prev() {
return _prev;
}
const T &get() const {
return value;
};
Element() {
color = RED;
right = NULL;
left = NULL;
parent = NULL;
_next = NULL;
_prev = NULL;
};
};
private:
struct _Data {
Element *_root;
Element *_nil;
int size_cache;
_FORCE_INLINE_ _Data() {
#ifdef GLOBALNIL_DISABLED
_nil = memnew_allocator(Element, A);
_nil->parent = _nil->left = _nil->right = _nil;
_nil->color = BLACK;
#else
_nil = (Element *)&_GlobalNilClass::_nil;
#endif
_root = NULL;
size_cache = 0;
}
void _create_root() {
_root = memnew_allocator(Element, A);
_root->parent = _root->left = _root->right = _nil;
_root->color = BLACK;
}
void _free_root() {
if (_root) {
memdelete_allocator<Element, A>(_root);
_root = NULL;
}
}
~_Data() {
_free_root();
#ifdef GLOBALNIL_DISABLED
memdelete_allocator<Element, A>(_nil);
#endif
}
};
_Data _data;
inline void _set_color(Element *p_node, int p_color) {
ERR_FAIL_COND(p_node == _data._nil && p_color == RED);
p_node->color = p_color;
}
inline void _rotate_left(Element *p_node) {
Element *r = p_node->right;
p_node->right = r->left;
if (r->left != _data._nil)
r->left->parent = p_node;
r->parent = p_node->parent;
if (p_node == p_node->parent->left)
p_node->parent->left = r;
else
p_node->parent->right = r;
r->left = p_node;
p_node->parent = r;
}
inline void _rotate_right(Element *p_node) {
Element *l = p_node->left;
p_node->left = l->right;
if (l->right != _data._nil)
l->right->parent = p_node;
l->parent = p_node->parent;
if (p_node == p_node->parent->right)
p_node->parent->right = l;
else
p_node->parent->left = l;
l->right = p_node;
p_node->parent = l;
}
inline Element *_successor(Element *p_node) const {
Element *node = p_node;
if (node->right != _data._nil) {
node = node->right;
while (node->left != _data._nil) { /* returns the minimum of the right subtree of node */
node = node->left;
}
return node;
} else {
while (node == node->parent->right) {
node = node->parent;
}
if (node->parent == _data._root)
return NULL; // No successor, as p_node = last node
return node->parent;
}
}
inline Element *_predecessor(Element *p_node) const {
Element *node = p_node;
if (node->left != _data._nil) {
node = node->left;
while (node->right != _data._nil) { /* returns the minimum of the left subtree of node */
node = node->right;
}
return node;
} else {
while (node == node->parent->left) {
node = node->parent;
}
if (node == _data._root)
return NULL; // No predecessor, as p_node = first node.
return node->parent;
}
}
Element *_find(const T &p_value) const {
Element *node = _data._root->left;
C less;
while (node != _data._nil) {
if (less(p_value, node->value))
node = node->left;
else if (less(node->value, p_value))
node = node->right;
else
return node; // found
}
return NULL;
}
Element *_lower_bound(const T &p_value) const {
Element *node = _data._root->left;
Element *prev = NULL;
C less;
while (node != _data._nil) {
prev = node;
if (less(p_value, node->value))
node = node->left;
else if (less(node->value, p_value))
node = node->right;
else
return node; // found
}
if (prev == NULL)
return NULL; // tree empty
if (less(prev->value, p_value))
prev = prev->_next;
return prev;
}
void _insert_rb_fix(Element *p_new_node) {
Element *node = p_new_node;
Element *nparent = node->parent;
Element *ngrand_parent;
while (nparent->color == RED) {
ngrand_parent = nparent->parent;
if (nparent == ngrand_parent->left) {
if (ngrand_parent->right->color == RED) {
_set_color(nparent, BLACK);
_set_color(ngrand_parent->right, BLACK);
_set_color(ngrand_parent, RED);
node = ngrand_parent;
nparent = node->parent;
} else {
if (node == nparent->right) {
_rotate_left(nparent);
node = nparent;
nparent = node->parent;
}
_set_color(nparent, BLACK);
_set_color(ngrand_parent, RED);
_rotate_right(ngrand_parent);
}
} else {
if (ngrand_parent->left->color == RED) {
_set_color(nparent, BLACK);
_set_color(ngrand_parent->left, BLACK);
_set_color(ngrand_parent, RED);
node = ngrand_parent;
nparent = node->parent;
} else {
if (node == nparent->left) {
_rotate_right(nparent);
node = nparent;
nparent = node->parent;
}
_set_color(nparent, BLACK);
_set_color(ngrand_parent, RED);
_rotate_left(ngrand_parent);
}
}
}
_set_color(_data._root->left, BLACK);
}
Element *_insert(const T &p_value) {
Element *new_parent = _data._root;
Element *node = _data._root->left;
C less;
while (node != _data._nil) {
new_parent = node;
if (less(p_value, node->value))
node = node->left;
else if (less(node->value, p_value))
node = node->right;
else {
return node; // Return existing node
}
}
Element *new_node = memnew_allocator(Element, A);
new_node->parent = new_parent;
new_node->right = _data._nil;
new_node->left = _data._nil;
new_node->value = p_value;
//new_node->data=_data;
if (new_parent == _data._root || less(p_value, new_parent->value)) {
new_parent->left = new_node;
} else {
new_parent->right = new_node;
}
new_node->_next = _successor(new_node);
new_node->_prev = _predecessor(new_node);
if (new_node->_next)
new_node->_next->_prev = new_node;
if (new_node->_prev)
new_node->_prev->_next = new_node;
_data.size_cache++;
_insert_rb_fix(new_node);
return new_node;
}
void _erase_fix_rb(Element *p_node) {
Element *root = _data._root->left;
Element *node = _data._nil;
Element *sibling = p_node;
Element *parent = sibling->parent;
while (node != root) { // If red node found, will exit at a break
if (sibling->color == RED) {
_set_color(sibling, BLACK);
_set_color(parent, RED);
if (sibling == parent->right) {
sibling = sibling->left;
_rotate_left(parent);
} else {
sibling = sibling->right;
_rotate_right(parent);
}
}
if ((sibling->left->color == BLACK) && (sibling->right->color == BLACK)) {
_set_color(sibling, RED);
if (parent->color == RED) {
_set_color(parent, BLACK);
break;
} else { // loop: haven't found any red nodes yet
node = parent;
parent = node->parent;
sibling = (node == parent->left) ? parent->right : parent->left;
}
} else {
if (sibling == parent->right) {
if (sibling->right->color == BLACK) {
_set_color(sibling->left, BLACK);
_set_color(sibling, RED);
_rotate_right(sibling);
sibling = sibling->parent;
}
_set_color(sibling, parent->color);
_set_color(parent, BLACK);
_set_color(sibling->right, BLACK);
_rotate_left(parent);
break;
} else {
if (sibling->left->color == BLACK) {
_set_color(sibling->right, BLACK);
_set_color(sibling, RED);
_rotate_left(sibling);
sibling = sibling->parent;
}
_set_color(sibling, parent->color);
_set_color(parent, BLACK);
_set_color(sibling->left, BLACK);
_rotate_right(parent);
break;
}
}
}
ERR_FAIL_COND(_data._nil->color != BLACK);
}
void _erase(Element *p_node) {
Element *rp = ((p_node->left == _data._nil) || (p_node->right == _data._nil)) ? p_node : p_node->_next;
Element *node = (rp->left == _data._nil) ? rp->right : rp->left;
Element *sibling;
if (rp == rp->parent->left) {
rp->parent->left = node;
sibling = rp->parent->right;
} else {
rp->parent->right = node;
sibling = rp->parent->left;
}
if (node->color == RED) {
node->parent = rp->parent;
_set_color(node, BLACK);
} else if (rp->color == BLACK && rp->parent != _data._root) {
_erase_fix_rb(sibling);
}
if (rp != p_node) {
ERR_FAIL_COND(rp == _data._nil);
rp->left = p_node->left;
rp->right = p_node->right;
rp->parent = p_node->parent;
rp->color = p_node->color;
if (p_node->left != _data._nil)
p_node->left->parent = rp;
if (p_node->right != _data._nil)
p_node->right->parent = rp;
if (p_node == p_node->parent->left) {
p_node->parent->left = rp;
} else {
p_node->parent->right = rp;
}
}
if (p_node->_next)
p_node->_next->_prev = p_node->_prev;
if (p_node->_prev)
p_node->_prev->_next = p_node->_next;
memdelete_allocator<Element, A>(p_node);
_data.size_cache--;
ERR_FAIL_COND(_data._nil->color == RED);
}
void _calculate_depth(Element *p_element, int &max_d, int d) const {
if (p_element == _data._nil)
return;
_calculate_depth(p_element->left, max_d, d + 1);
_calculate_depth(p_element->right, max_d, d + 1);
if (d > max_d)
max_d = d;
}
void _cleanup_tree(Element *p_element) {
if (p_element == _data._nil)
return;
_cleanup_tree(p_element->left);
_cleanup_tree(p_element->right);
memdelete_allocator<Element, A>(p_element);
}
void _copy_from(const Set &p_set) {
clear();
// not the fastest way, but safeset to write.
for (Element *I = p_set.front(); I; I = I->next()) {
insert(I->get());
}
}
public:
const Element *find(const T &p_value) const {
if (!_data._root)
return NULL;
const Element *res = _find(p_value);
return res;
}
Element *find(const T &p_value) {
if (!_data._root)
return NULL;
Element *res = _find(p_value);
return res;
}
Element *lower_bound(const T &p_value) const {
return _lower_bound(p_value);
}
bool has(const T &p_value) const {
return find(p_value) != NULL;
}
Element *insert(const T &p_value) {
if (!_data._root)
_data._create_root();
return _insert(p_value);
}
void erase(Element *p_element) {
if (!_data._root || !p_element)
return;
_erase(p_element);
if (_data.size_cache == 0 && _data._root)
_data._free_root();
}
bool erase(const T &p_value) {
if (!_data._root)
return false;
Element *e = find(p_value);
if (!e)
return false;
_erase(e);
if (_data.size_cache == 0 && _data._root)
_data._free_root();
return true;
}
Element *front() const {
if (!_data._root)
return NULL;
Element *e = _data._root->left;
if (e == _data._nil)
return NULL;
while (e->left != _data._nil)
e = e->left;
return e;
}
Element *back() const {
if (!_data._root)
return NULL;
Element *e = _data._root->left;
if (e == _data._nil)
return NULL;
while (e->right != _data._nil)
e = e->right;
return e;
}
inline bool empty() const { return _data.size_cache == 0; }
inline int size() const { return _data.size_cache; }
int calculate_depth() const {
// used for debug mostly
if (!_data._root)
return 0;
int max_d = 0;
_calculate_depth(_data._root->left, max_d, 0);
return max_d;
}
void clear() {
if (!_data._root)
return;
_cleanup_tree(_data._root->left);
_data._root->left = _data._nil;
_data.size_cache = 0;
_data._free_root();
}
void operator=(const Set &p_set) {
_copy_from(p_set);
}
Set(const Set &p_set) {
_copy_from(p_set);
}
_FORCE_INLINE_ Set() {
}
~Set() {
clear();
}
};
#endif