393 lines
12 KiB
C
393 lines
12 KiB
C
/*
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* Red-black search tree support
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*
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* Copyright 2009 Henri Verbeet
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* Copyright 2009 Andrew Riedi
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* Copyright 2016 Jacek Caban for CodeWeavers
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
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*/
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#ifndef __WINE_WINE_RBTREE_H
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#define __WINE_WINE_RBTREE_H
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#define WINE_RB_ENTRY_VALUE(element, type, field) \
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((type *)((char *)(element) - offsetof(type, field)))
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struct wine_rb_entry
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{
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struct wine_rb_entry *parent;
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struct wine_rb_entry *left;
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struct wine_rb_entry *right;
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unsigned int flags;
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};
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typedef int (*wine_rb_compare_func_t)(const void *key, const struct wine_rb_entry *entry);
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struct wine_rb_tree
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{
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wine_rb_compare_func_t compare;
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struct wine_rb_entry *root;
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};
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typedef void (wine_rb_traverse_func_t)(struct wine_rb_entry *entry, void *context);
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#define WINE_RB_FLAG_RED 0x1
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static inline int wine_rb_is_red(struct wine_rb_entry *entry)
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{
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return entry && (entry->flags & WINE_RB_FLAG_RED);
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}
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static inline void wine_rb_rotate_left(struct wine_rb_tree *tree, struct wine_rb_entry *e)
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{
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struct wine_rb_entry *right = e->right;
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if (!e->parent)
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tree->root = right;
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else if (e->parent->left == e)
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e->parent->left = right;
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else
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e->parent->right = right;
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e->right = right->left;
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if (e->right) e->right->parent = e;
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right->left = e;
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right->parent = e->parent;
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e->parent = right;
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}
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static inline void wine_rb_rotate_right(struct wine_rb_tree *tree, struct wine_rb_entry *e)
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{
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struct wine_rb_entry *left = e->left;
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if (!e->parent)
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tree->root = left;
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else if (e->parent->left == e)
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e->parent->left = left;
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else
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e->parent->right = left;
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e->left = left->right;
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if (e->left) e->left->parent = e;
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left->right = e;
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left->parent = e->parent;
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e->parent = left;
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}
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static inline void wine_rb_flip_color(struct wine_rb_entry *entry)
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{
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entry->flags ^= WINE_RB_FLAG_RED;
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entry->left->flags ^= WINE_RB_FLAG_RED;
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entry->right->flags ^= WINE_RB_FLAG_RED;
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}
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static inline struct wine_rb_entry *wine_rb_head(struct wine_rb_entry *iter)
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{
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if (!iter) return NULL;
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while (iter->left) iter = iter->left;
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return iter;
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}
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static inline struct wine_rb_entry *wine_rb_tail(struct wine_rb_entry *iter)
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{
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if (!iter) return NULL;
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while (iter->right) iter = iter->right;
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return iter;
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}
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static inline struct wine_rb_entry *wine_rb_next(struct wine_rb_entry *iter)
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{
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if (iter->right) return wine_rb_head(iter->right);
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while (iter->parent && iter->parent->right == iter) iter = iter->parent;
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return iter->parent;
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}
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static inline struct wine_rb_entry *wine_rb_prev(struct wine_rb_entry *iter)
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{
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if (iter->left) return wine_rb_tail(iter->left);
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while (iter->parent && iter->parent->left == iter) iter = iter->parent;
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return iter->parent;
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}
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static inline struct wine_rb_entry *wine_rb_postorder_head(struct wine_rb_entry *iter)
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{
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if (!iter) return NULL;
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for (;;) {
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while (iter->left) iter = iter->left;
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if (!iter->right) return iter;
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iter = iter->right;
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}
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}
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static inline struct wine_rb_entry *wine_rb_postorder_next(struct wine_rb_entry *iter)
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{
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if (!iter->parent) return NULL;
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if (iter == iter->parent->right || !iter->parent->right) return iter->parent;
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return wine_rb_postorder_head(iter->parent->right);
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}
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/* iterate through the tree */
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#define WINE_RB_FOR_EACH(cursor, tree) \
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for ((cursor) = wine_rb_head((tree)->root); (cursor); (cursor) = wine_rb_next(cursor))
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/* iterate through the tree using a tree entry */
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#define WINE_RB_FOR_EACH_ENTRY(elem, tree, type, field) \
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for ((elem) = WINE_RB_ENTRY_VALUE(wine_rb_head((tree)->root), type, field); \
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&(elem)->field; \
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(elem) = WINE_RB_ENTRY_VALUE(wine_rb_next(&elem->field), type, field))
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/* iterate through the tree using using postorder, making it safe to free the entry */
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#define WINE_RB_FOR_EACH_DESTRUCTOR(cursor, cursor2, tree) \
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for ((cursor) = wine_rb_postorder_head((tree)->root); \
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(cursor) && (((cursor2) = wine_rb_postorder_next(cursor)) || 1); \
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(cursor) = (cursor2))
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/* iterate through the tree using a tree entry and postorder, making it safe to free the entry */
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#define WINE_RB_FOR_EACH_ENTRY_DESTRUCTOR(elem, elem2, tree, type, field) \
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for ((elem) = WINE_RB_ENTRY_VALUE(wine_rb_postorder_head((tree)->root), type, field); \
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&(elem)->field \
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&& (((elem2) = WINE_RB_ENTRY_VALUE(wine_rb_postorder_next(&(elem)->field), type, field)) || 1); \
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(elem) = (elem2))
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static inline void wine_rb_postorder(struct wine_rb_tree *tree, wine_rb_traverse_func_t *callback, void *context)
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{
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struct wine_rb_entry *iter, *next;
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WINE_RB_FOR_EACH_DESTRUCTOR(iter, next, tree) callback(iter, context);
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}
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static inline void wine_rb_init(struct wine_rb_tree *tree, wine_rb_compare_func_t compare)
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{
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tree->compare = compare;
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tree->root = NULL;
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}
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static inline void wine_rb_for_each_entry(struct wine_rb_tree *tree, wine_rb_traverse_func_t *callback, void *context)
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{
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struct wine_rb_entry *iter;
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WINE_RB_FOR_EACH(iter, tree) callback(iter, context);
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}
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static inline void wine_rb_clear(struct wine_rb_tree *tree, wine_rb_traverse_func_t *callback, void *context)
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{
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/* Note that we use postorder here because the callback will likely free the entry. */
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if (callback) wine_rb_postorder(tree, callback, context);
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tree->root = NULL;
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}
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static inline void wine_rb_destroy(struct wine_rb_tree *tree, wine_rb_traverse_func_t *callback, void *context)
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{
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wine_rb_clear(tree, callback, context);
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}
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static inline struct wine_rb_entry *wine_rb_get(const struct wine_rb_tree *tree, const void *key)
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{
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struct wine_rb_entry *entry = tree->root;
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while (entry)
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{
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int c = tree->compare(key, entry);
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if (!c) return entry;
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entry = c < 0 ? entry->left : entry->right;
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}
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return NULL;
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}
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static inline int wine_rb_put(struct wine_rb_tree *tree, const void *key, struct wine_rb_entry *entry)
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{
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struct wine_rb_entry **iter = &tree->root, *parent = tree->root;
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while (*iter)
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{
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int c;
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parent = *iter;
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c = tree->compare(key, parent);
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if (!c) return -1;
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else if (c < 0) iter = &parent->left;
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else iter = &parent->right;
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}
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entry->flags = WINE_RB_FLAG_RED;
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entry->parent = parent;
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entry->left = NULL;
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entry->right = NULL;
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*iter = entry;
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while (wine_rb_is_red(entry->parent))
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{
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if (entry->parent == entry->parent->parent->left)
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{
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if (wine_rb_is_red(entry->parent->parent->right))
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{
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wine_rb_flip_color(entry->parent->parent);
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entry = entry->parent->parent;
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}
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else
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{
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if (entry == entry->parent->right)
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{
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entry = entry->parent;
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wine_rb_rotate_left(tree, entry);
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}
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entry->parent->flags &= ~WINE_RB_FLAG_RED;
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entry->parent->parent->flags |= WINE_RB_FLAG_RED;
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wine_rb_rotate_right(tree, entry->parent->parent);
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}
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}
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else
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{
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if (wine_rb_is_red(entry->parent->parent->left))
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{
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wine_rb_flip_color(entry->parent->parent);
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entry = entry->parent->parent;
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}
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else
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{
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if (entry == entry->parent->left)
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{
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entry = entry->parent;
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wine_rb_rotate_right(tree, entry);
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}
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entry->parent->flags &= ~WINE_RB_FLAG_RED;
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entry->parent->parent->flags |= WINE_RB_FLAG_RED;
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wine_rb_rotate_left(tree, entry->parent->parent);
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}
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}
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}
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tree->root->flags &= ~WINE_RB_FLAG_RED;
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return 0;
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}
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static inline void wine_rb_remove(struct wine_rb_tree *tree, struct wine_rb_entry *entry)
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{
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struct wine_rb_entry *iter, *child, *parent, *w;
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int need_fixup;
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if (entry->right && entry->left)
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for(iter = entry->right; iter->left; iter = iter->left);
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else
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iter = entry;
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child = iter->left ? iter->left : iter->right;
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if (!iter->parent)
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tree->root = child;
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else if (iter == iter->parent->left)
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iter->parent->left = child;
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else
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iter->parent->right = child;
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if (child) child->parent = iter->parent;
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parent = iter->parent;
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need_fixup = !wine_rb_is_red(iter);
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if (entry != iter)
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{
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*iter = *entry;
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if (!iter->parent)
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tree->root = iter;
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else if (entry == iter->parent->left)
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iter->parent->left = iter;
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else
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iter->parent->right = iter;
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if (iter->right) iter->right->parent = iter;
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if (iter->left) iter->left->parent = iter;
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if (parent == entry) parent = iter;
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}
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if (need_fixup)
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{
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while (parent && !wine_rb_is_red(child))
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{
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if (child == parent->left)
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{
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w = parent->right;
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if (wine_rb_is_red(w))
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{
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w->flags &= ~WINE_RB_FLAG_RED;
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parent->flags |= WINE_RB_FLAG_RED;
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wine_rb_rotate_left(tree, parent);
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w = parent->right;
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}
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if (wine_rb_is_red(w->left) || wine_rb_is_red(w->right))
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{
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if (!wine_rb_is_red(w->right))
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{
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w->left->flags &= ~WINE_RB_FLAG_RED;
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w->flags |= WINE_RB_FLAG_RED;
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wine_rb_rotate_right(tree, w);
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w = parent->right;
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}
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w->flags = (w->flags & ~WINE_RB_FLAG_RED) | (parent->flags & WINE_RB_FLAG_RED);
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parent->flags &= ~WINE_RB_FLAG_RED;
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if (w->right)
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w->right->flags &= ~WINE_RB_FLAG_RED;
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wine_rb_rotate_left(tree, parent);
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child = NULL;
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break;
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}
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}
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else
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{
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w = parent->left;
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if (wine_rb_is_red(w))
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{
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w->flags &= ~WINE_RB_FLAG_RED;
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parent->flags |= WINE_RB_FLAG_RED;
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wine_rb_rotate_right(tree, parent);
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w = parent->left;
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}
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if (wine_rb_is_red(w->left) || wine_rb_is_red(w->right))
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{
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if (!wine_rb_is_red(w->left))
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{
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w->right->flags &= ~WINE_RB_FLAG_RED;
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w->flags |= WINE_RB_FLAG_RED;
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wine_rb_rotate_left(tree, w);
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w = parent->left;
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}
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w->flags = (w->flags & ~WINE_RB_FLAG_RED) | (parent->flags & WINE_RB_FLAG_RED);
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parent->flags &= ~WINE_RB_FLAG_RED;
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if (w->left)
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w->left->flags &= ~WINE_RB_FLAG_RED;
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wine_rb_rotate_right(tree, parent);
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child = NULL;
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break;
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}
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}
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w->flags |= WINE_RB_FLAG_RED;
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child = parent;
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parent = child->parent;
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}
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if (child) child->flags &= ~WINE_RB_FLAG_RED;
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}
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if (tree->root) tree->root->flags &= ~WINE_RB_FLAG_RED;
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}
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static inline void wine_rb_remove_key(struct wine_rb_tree *tree, const void *key)
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{
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struct wine_rb_entry *entry = wine_rb_get(tree, key);
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if (entry) wine_rb_remove(tree, entry);
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}
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#endif /* __WINE_WINE_RBTREE_H */
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