From 484cde13270c18327dc4277f20250e48a23b0d69 Mon Sep 17 00:00:00 2001 From: Henri Verbeet Date: Wed, 3 Jun 2009 10:47:26 +0200 Subject: [PATCH] include: Add a generic red-black tree. --- include/wine/rbtree.h | 342 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 342 insertions(+) create mode 100644 include/wine/rbtree.h diff --git a/include/wine/rbtree.h b/include/wine/rbtree.h new file mode 100644 index 00000000000..de29d10c49e --- /dev/null +++ b/include/wine/rbtree.h @@ -0,0 +1,342 @@ +/* + * Red-black search tree support + * + * Copyright 2009 Henri Verbeet + * Copyright 2009 Andrew Riedi + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA + */ + +#ifndef __WINE_WINE_RBTREE_H +#define __WINE_WINE_RBTREE_H + +#define WINE_RB_ENTRY_VALUE(element, type, field) \ + ((type *)((char *)(element) - FIELD_OFFSET(type, field))) + +struct wine_rb_entry +{ + struct wine_rb_entry *left; + struct wine_rb_entry *right; + unsigned int flags; +}; + +struct wine_rb_stack +{ + struct wine_rb_entry ***entries; + size_t count; + size_t size; +}; + +struct wine_rb_functions +{ + void *(*alloc)(size_t size); + void *(*realloc)(void *ptr, size_t size); + void (*free)(void *ptr); + int (*compare)(const void *key, const struct wine_rb_entry *entry); +}; + +struct wine_rb_tree +{ + const struct wine_rb_functions *functions; + struct wine_rb_entry *root; + struct wine_rb_stack stack; +}; + +typedef void (wine_rb_traverse_func_t)(struct wine_rb_entry *entry, void *context); + +#define WINE_RB_FLAG_RED 0x1 +#define WINE_RB_FLAG_STOP 0x2 +#define WINE_RB_FLAG_TRAVERSED_LEFT 0x4 +#define WINE_RB_FLAG_TRAVERSED_RIGHT 0x8 + +static inline void wine_rb_stack_clear(struct wine_rb_stack *stack) +{ + stack->count = 0; +} + +static inline void wine_rb_stack_push(struct wine_rb_stack *stack, struct wine_rb_entry **entry) +{ + stack->entries[stack->count++] = entry; +} + +static inline int wine_rb_ensure_stack_size(struct wine_rb_tree *tree, size_t size) +{ + struct wine_rb_stack *stack = &tree->stack; + + if (size > stack->size) + { + size_t new_size = stack->size << 1; + struct wine_rb_entry ***new_entries = tree->functions->realloc(stack->entries, + new_size * sizeof(*stack->entries)); + + if (!new_entries) return -1; + + stack->entries = new_entries; + stack->size = new_size; + } + + return 0; +} + +static inline int wine_rb_is_red(struct wine_rb_entry *entry) +{ + return entry && (entry->flags & WINE_RB_FLAG_RED); +} + +static inline void wine_rb_rotate_left(struct wine_rb_entry **entry) +{ + struct wine_rb_entry *e = *entry; + struct wine_rb_entry *right = e->right; + + e->right = right->left; + right->left = e; + right->flags &= ~WINE_RB_FLAG_RED; + right->flags |= e->flags & WINE_RB_FLAG_RED; + e->flags |= WINE_RB_FLAG_RED; + *entry = right; +} + +static inline void wine_rb_rotate_right(struct wine_rb_entry **entry) +{ + struct wine_rb_entry *e = *entry; + struct wine_rb_entry *left = e->left; + + e->left = left->right; + left->right = e; + left->flags &= ~WINE_RB_FLAG_RED; + left->flags |= e->flags & WINE_RB_FLAG_RED; + e->flags |= WINE_RB_FLAG_RED; + *entry = left; +} + +static inline void wine_rb_flip_color(struct wine_rb_entry *entry) +{ + entry->flags ^= WINE_RB_FLAG_RED; + entry->left->flags ^= WINE_RB_FLAG_RED; + entry->right->flags ^= WINE_RB_FLAG_RED; +} + +static inline void wine_rb_fixup(struct wine_rb_stack *stack) +{ + while (stack->count) + { + struct wine_rb_entry **entry = stack->entries[stack->count - 1]; + + if ((*entry)->flags & WINE_RB_FLAG_STOP) + { + (*entry)->flags &= ~WINE_RB_FLAG_STOP; + return; + } + + if (wine_rb_is_red((*entry)->right) && !wine_rb_is_red((*entry)->left)) wine_rb_rotate_left(entry); + if (wine_rb_is_red((*entry)->left) && wine_rb_is_red((*entry)->left->left)) wine_rb_rotate_right(entry); + if (wine_rb_is_red((*entry)->left) && wine_rb_is_red((*entry)->right)) wine_rb_flip_color(*entry); + --stack->count; + } +} + +static inline void wine_rb_move_red_left(struct wine_rb_entry **entry) +{ + wine_rb_flip_color(*entry); + if (wine_rb_is_red((*entry)->right->left)) + { + wine_rb_rotate_right(&(*entry)->right); + wine_rb_rotate_left(entry); + wine_rb_flip_color(*entry); + } +} + +static inline void wine_rb_move_red_right(struct wine_rb_entry **entry) +{ + wine_rb_flip_color(*entry); + if (wine_rb_is_red((*entry)->left->left)) + { + wine_rb_rotate_right(entry); + wine_rb_flip_color(*entry); + } +} + +static inline void wine_rb_postorder(struct wine_rb_tree *tree, wine_rb_traverse_func_t *callback, void *context) +{ + struct wine_rb_entry **entry; + + if (!tree->root) return; + + for (entry = &tree->root;;) + { + struct wine_rb_entry *e = *entry; + + if (e->left && !(e->flags & WINE_RB_FLAG_TRAVERSED_LEFT)) + { + wine_rb_stack_push(&tree->stack, entry); + e->flags |= WINE_RB_FLAG_TRAVERSED_LEFT; + entry = &e->left; + continue; + } + + if (e->right && !(e->flags & WINE_RB_FLAG_TRAVERSED_RIGHT)) + { + wine_rb_stack_push(&tree->stack, entry); + e->flags |= WINE_RB_FLAG_TRAVERSED_RIGHT; + entry = &e->right; + continue; + } + + e->flags &= ~(WINE_RB_FLAG_TRAVERSED_LEFT | WINE_RB_FLAG_TRAVERSED_RIGHT); + callback(e, context); + + if (!tree->stack.count) break; + entry = tree->stack.entries[--tree->stack.count]; + } +} + +static inline int wine_rb_init(struct wine_rb_tree *tree, const struct wine_rb_functions *functions) +{ + tree->functions = functions; + tree->root = NULL; + + tree->stack.entries = functions->alloc(16 * sizeof(*tree->stack.entries)); + if (!tree->stack.entries) return -1; + tree->stack.size = 16; + tree->stack.count = 0; + + return 0; +} + +static inline void wine_rb_for_each_entry(struct wine_rb_tree *tree, wine_rb_traverse_func_t *callback, void *context) +{ + wine_rb_postorder(tree, callback, context); +} + +static inline void wine_rb_destroy(struct wine_rb_tree *tree, wine_rb_traverse_func_t *callback, void *context) +{ + /* Note that we use postorder here because the callback will likely free the entry. */ + if (callback) wine_rb_postorder(tree, callback, context); + + tree->root = NULL; + tree->functions->free(tree->stack.entries); +} + +static inline struct wine_rb_entry *wine_rb_get(const struct wine_rb_tree *tree, const void *key) +{ + struct wine_rb_entry *entry = tree->root; + while (entry) + { + int c = tree->functions->compare(key, entry); + if (!c) return entry; + entry = c < 0 ? entry->left : entry->right; + } + return NULL; +} + +static inline int wine_rb_put(struct wine_rb_tree *tree, const void *key, struct wine_rb_entry *entry) +{ + struct wine_rb_entry **parent = &tree->root; + size_t black_height = 1; + + while (*parent) + { + int c; + + if (!wine_rb_is_red(*parent)) ++black_height; + + wine_rb_stack_push(&tree->stack, parent); + + c = tree->functions->compare(key, *parent); + if (!c) + { + wine_rb_stack_clear(&tree->stack); + return -1; + } + else if (c < 0) parent = &(*parent)->left; + else parent = &(*parent)->right; + } + + /* After insertion, the path length to any node should be <= (black_height + 1) * 2. */ + if (wine_rb_ensure_stack_size(tree, black_height << 1) == -1) + { + wine_rb_stack_clear(&tree->stack); + return -1; + } + + entry->flags = WINE_RB_FLAG_RED; + entry->left = NULL; + entry->right = NULL; + *parent = entry; + + wine_rb_fixup(&tree->stack); + tree->root->flags &= ~WINE_RB_FLAG_RED; + + return 0; +} + +static inline void wine_rb_remove(struct wine_rb_tree *tree, const void *key) +{ + struct wine_rb_entry **entry = &tree->root; + + while (*entry) + { + if (tree->functions->compare(key, *entry) < 0) + { + wine_rb_stack_push(&tree->stack, entry); + if (!wine_rb_is_red((*entry)->left) && !wine_rb_is_red((*entry)->left->left)) wine_rb_move_red_left(entry); + entry = &(*entry)->left; + } + else + { + if (wine_rb_is_red((*entry)->left)) wine_rb_rotate_right(entry); + if (!tree->functions->compare(key, *entry) && !(*entry)->right) + { + *entry = NULL; + break; + } + if (!wine_rb_is_red((*entry)->right) && !wine_rb_is_red((*entry)->right->left)) + wine_rb_move_red_right(entry); + if (!tree->functions->compare(key, *entry)) + { + struct wine_rb_entry **e = &(*entry)->right; + struct wine_rb_entry *m = *e; + while (m->left) m = m->left; + + wine_rb_stack_push(&tree->stack, entry); + (*entry)->flags |= WINE_RB_FLAG_STOP; + + while ((*e)->left) + { + wine_rb_stack_push(&tree->stack, e); + if (!wine_rb_is_red((*e)->left) && !wine_rb_is_red((*e)->left->left)) wine_rb_move_red_left(e); + e = &(*e)->left; + } + *e = NULL; + wine_rb_fixup(&tree->stack); + + *m = **entry; + *entry = m; + + break; + } + else + { + wine_rb_stack_push(&tree->stack, entry); + entry = &(*entry)->right; + } + } + } + + wine_rb_fixup(&tree->stack); + if (tree->root) tree->root->flags &= ~WINE_RB_FLAG_RED; +} + +#endif /* __WINE_WINE_RBTREE_H */