Sweden-Number/include/wine/rbtree.h

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2009-06-03 10:47:26 +02:00
/*
* 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) - offsetof(type, field)))
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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_clear(struct wine_rb_tree *tree, wine_rb_traverse_func_t *callback, void *context)
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{
/* 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;
}
static inline void wine_rb_destroy(struct wine_rb_tree *tree, wine_rb_traverse_func_t *callback, void *context)
{
wine_rb_clear(tree, callback, context);
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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 */