include: Add a generic red-black tree.
This commit is contained in:
Henri Verbeet
Alexandre Julliard
parent
97f320a77b
commit
484cde1327
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@ -0,0 +1,342 @@
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/*
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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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*
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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) - FIELD_OFFSET(type, field)))
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struct wine_rb_entry
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{
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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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struct wine_rb_stack
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{
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struct wine_rb_entry ***entries;
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size_t count;
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size_t size;
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};
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struct wine_rb_functions
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{
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void *(*alloc)(size_t size);
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void *(*realloc)(void *ptr, size_t size);
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void (*free)(void *ptr);
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int (*compare)(const void *key, const struct wine_rb_entry *entry);
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};
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struct wine_rb_tree
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{
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const struct wine_rb_functions *functions;
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struct wine_rb_entry *root;
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struct wine_rb_stack stack;
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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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#define WINE_RB_FLAG_STOP 0x2
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#define WINE_RB_FLAG_TRAVERSED_LEFT 0x4
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#define WINE_RB_FLAG_TRAVERSED_RIGHT 0x8
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static inline void wine_rb_stack_clear(struct wine_rb_stack *stack)
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{
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stack->count = 0;
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}
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static inline void wine_rb_stack_push(struct wine_rb_stack *stack, struct wine_rb_entry **entry)
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{
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stack->entries[stack->count++] = entry;
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}
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static inline int wine_rb_ensure_stack_size(struct wine_rb_tree *tree, size_t size)
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{
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struct wine_rb_stack *stack = &tree->stack;
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if (size > stack->size)
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{
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size_t new_size = stack->size << 1;
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struct wine_rb_entry ***new_entries = tree->functions->realloc(stack->entries,
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new_size * sizeof(*stack->entries));
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if (!new_entries) return -1;
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stack->entries = new_entries;
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stack->size = new_size;
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}
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return 0;
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}
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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_entry **entry)
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{
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struct wine_rb_entry *e = *entry;
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struct wine_rb_entry *right = e->right;
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e->right = right->left;
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right->left = e;
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right->flags &= ~WINE_RB_FLAG_RED;
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right->flags |= e->flags & WINE_RB_FLAG_RED;
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e->flags |= WINE_RB_FLAG_RED;
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*entry = right;
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}
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static inline void wine_rb_rotate_right(struct wine_rb_entry **entry)
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{
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struct wine_rb_entry *e = *entry;
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struct wine_rb_entry *left = e->left;
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e->left = left->right;
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left->right = e;
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left->flags &= ~WINE_RB_FLAG_RED;
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left->flags |= e->flags & WINE_RB_FLAG_RED;
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e->flags |= WINE_RB_FLAG_RED;
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*entry = 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 void wine_rb_fixup(struct wine_rb_stack *stack)
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{
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while (stack->count)
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{
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struct wine_rb_entry **entry = stack->entries[stack->count - 1];
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if ((*entry)->flags & WINE_RB_FLAG_STOP)
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{
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(*entry)->flags &= ~WINE_RB_FLAG_STOP;
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return;
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}
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if (wine_rb_is_red((*entry)->right) && !wine_rb_is_red((*entry)->left)) wine_rb_rotate_left(entry);
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if (wine_rb_is_red((*entry)->left) && wine_rb_is_red((*entry)->left->left)) wine_rb_rotate_right(entry);
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if (wine_rb_is_red((*entry)->left) && wine_rb_is_red((*entry)->right)) wine_rb_flip_color(*entry);
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--stack->count;
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}
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}
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static inline void wine_rb_move_red_left(struct wine_rb_entry **entry)
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{
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wine_rb_flip_color(*entry);
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if (wine_rb_is_red((*entry)->right->left))
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{
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wine_rb_rotate_right(&(*entry)->right);
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wine_rb_rotate_left(entry);
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wine_rb_flip_color(*entry);
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}
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}
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static inline void wine_rb_move_red_right(struct wine_rb_entry **entry)
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{
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wine_rb_flip_color(*entry);
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if (wine_rb_is_red((*entry)->left->left))
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{
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wine_rb_rotate_right(entry);
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wine_rb_flip_color(*entry);
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}
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}
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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 **entry;
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if (!tree->root) return;
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for (entry = &tree->root;;)
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{
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struct wine_rb_entry *e = *entry;
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if (e->left && !(e->flags & WINE_RB_FLAG_TRAVERSED_LEFT))
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{
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wine_rb_stack_push(&tree->stack, entry);
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e->flags |= WINE_RB_FLAG_TRAVERSED_LEFT;
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entry = &e->left;
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continue;
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}
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if (e->right && !(e->flags & WINE_RB_FLAG_TRAVERSED_RIGHT))
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{
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wine_rb_stack_push(&tree->stack, entry);
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e->flags |= WINE_RB_FLAG_TRAVERSED_RIGHT;
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entry = &e->right;
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continue;
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}
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e->flags &= ~(WINE_RB_FLAG_TRAVERSED_LEFT | WINE_RB_FLAG_TRAVERSED_RIGHT);
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callback(e, context);
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if (!tree->stack.count) break;
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entry = tree->stack.entries[--tree->stack.count];
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}
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}
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static inline int wine_rb_init(struct wine_rb_tree *tree, const struct wine_rb_functions *functions)
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{
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tree->functions = functions;
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tree->root = NULL;
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tree->stack.entries = functions->alloc(16 * sizeof(*tree->stack.entries));
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if (!tree->stack.entries) return -1;
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tree->stack.size = 16;
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tree->stack.count = 0;
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return 0;
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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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wine_rb_postorder(tree, callback, context);
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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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/* 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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tree->functions->free(tree->stack.entries);
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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->functions->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 **parent = &tree->root;
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size_t black_height = 1;
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while (*parent)
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{
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int c;
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if (!wine_rb_is_red(*parent)) ++black_height;
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wine_rb_stack_push(&tree->stack, parent);
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c = tree->functions->compare(key, *parent);
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if (!c)
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{
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wine_rb_stack_clear(&tree->stack);
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return -1;
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}
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else if (c < 0) parent = &(*parent)->left;
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else parent = &(*parent)->right;
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}
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/* After insertion, the path length to any node should be <= (black_height + 1) * 2. */
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if (wine_rb_ensure_stack_size(tree, black_height << 1) == -1)
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{
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wine_rb_stack_clear(&tree->stack);
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return -1;
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}
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entry->flags = WINE_RB_FLAG_RED;
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entry->left = NULL;
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entry->right = NULL;
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*parent = entry;
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wine_rb_fixup(&tree->stack);
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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, 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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if (tree->functions->compare(key, *entry) < 0)
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{
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wine_rb_stack_push(&tree->stack, entry);
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if (!wine_rb_is_red((*entry)->left) && !wine_rb_is_red((*entry)->left->left)) wine_rb_move_red_left(entry);
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entry = &(*entry)->left;
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}
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else
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{
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if (wine_rb_is_red((*entry)->left)) wine_rb_rotate_right(entry);
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if (!tree->functions->compare(key, *entry) && !(*entry)->right)
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{
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*entry = NULL;
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break;
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}
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if (!wine_rb_is_red((*entry)->right) && !wine_rb_is_red((*entry)->right->left))
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wine_rb_move_red_right(entry);
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if (!tree->functions->compare(key, *entry))
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{
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struct wine_rb_entry **e = &(*entry)->right;
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struct wine_rb_entry *m = *e;
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while (m->left) m = m->left;
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wine_rb_stack_push(&tree->stack, entry);
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(*entry)->flags |= WINE_RB_FLAG_STOP;
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while ((*e)->left)
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{
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wine_rb_stack_push(&tree->stack, e);
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if (!wine_rb_is_red((*e)->left) && !wine_rb_is_red((*e)->left->left)) wine_rb_move_red_left(e);
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e = &(*e)->left;
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}
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*e = NULL;
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wine_rb_fixup(&tree->stack);
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*m = **entry;
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*entry = m;
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break;
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}
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else
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{
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wine_rb_stack_push(&tree->stack, entry);
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entry = &(*entry)->right;
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}
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}
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}
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wine_rb_fixup(&tree->stack);
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if (tree->root) tree->root->flags &= ~WINE_RB_FLAG_RED;
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}
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#endif /* __WINE_WINE_RBTREE_H */
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