/*
* Copyright (c) 2013 Richard Braun.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
/*
* Copyright (c) 2011 Richard Braun.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*
* Radix tree.
*
* In addition to the standard insertion operation, this implementation
* can allocate keys for the caller at insertion time.
*/
#ifndef _RDXTREE_H
#define _RDXTREE_H
#include
/*
* Radix tree.
*/
struct rdxtree {
unsigned int height;
void *root;
};
/*
* Radix tree iterator.
*
* Don't use directly - use rdxtree_for_each() instead.
*/
struct rdxtree_iter {
void *node;
void **slot;
};
/*
* Static tree initializer.
*/
#define RDXTREE_INITIALIZER { 0, NULL }
/*
* Initialize a tree.
*/
static inline void
rdxtree_init(struct rdxtree *tree)
{
tree->height = 0;
tree->root = NULL;
}
/*
* Initialize an iterator.
*/
static inline void
rdxtree_iter_init(struct rdxtree_iter *iter)
{
iter->node = NULL;
iter->slot = NULL;
}
/*
* Insert a pointer in a tree.
*
* The ptr parameter must not be null.
*/
int rdxtree_insert(struct rdxtree *tree, unsigned long key, void *ptr);
/*
* Insert a pointer in a tree and obtain its slot.
*
* The ptr and slotp parameters must not be null. If successful, the slot of
* the newly inserted pointer is stored at the address pointed to by the slotp
* parameter.
*/
int rdxtree_insert_slot(struct rdxtree *tree, unsigned long key, void *ptr,
void ***slotp);
/*
* Insert a pointer in a tree, for which a new key is allocated.
*
* The ptr and keyp parameters must not be null. The newly allocated key is
* stored at the address pointed to by the keyp parameter.
*/
int rdxtree_insert_alloc(struct rdxtree *tree, void *ptr, unsigned long *keyp);
/*
* Insert a pointer in a tree, for which a new key is allocated, and obtain
* its slot.
*
* The ptr, keyp and slotp parameters must not be null. The newly allocated
* key is stored at the address pointed to by the keyp parameter while the
* slot of the inserted pointer is stored at the address pointed to by the
* slotp parameter.
*/
int rdxtree_insert_alloc_slot(struct rdxtree *tree, void *ptr,
unsigned long *keyp, void ***slotp);
/*
* Remove a pointer from a tree.
*
* The matching pointer is returned if successful, null otherwise.
*/
void * rdxtree_remove(struct rdxtree *tree, unsigned long key);
/*
* Look up a pointer in a tree.
*
* The matching pointer is returned if successful, null otherwise.
*/
void * rdxtree_lookup(struct rdxtree *tree, unsigned long key);
/*
* Look up a slot in a tree.
*
* A slot is a pointer to a contained pointer in a tree. It can be used as
* a placeholder for fast replacements to avoid multiple lookups on the same
* key.
*
* A slot for the matching pointer is returned if successful, null otherwise.
*
* See rdxtree_replace_slot().
*/
void ** rdxtree_lookup_slot(struct rdxtree *tree, unsigned long key);
/*
* Replace a pointer in a tree.
*
* The ptr parameter must not be null. The previous pointer is returned.
*
* See rdxtree_lookup_slot().
*/
void * rdxtree_replace_slot(void **slot, void *ptr);
/*
* Walk pointers in a tree.
*
* Move the iterator to the next pointer in the given tree.
*
* The next pointer is returned if there is one, null otherwise.
*/
void * rdxtree_iter_next(struct rdxtree *tree, struct rdxtree_iter *iter);
/*
* Forge a loop to process all pointers of a tree.
*/
#define rdxtree_for_each(tree, iter, ptr) \
for (rdxtree_iter_init(iter), ptr = rdxtree_iter_next(tree, iter); \
ptr != NULL; \
ptr = rdxtree_iter_next(tree, iter))
/*
* Remove all pointers from a tree.
*
* The common way to destroy a tree and its pointers is to loop over all
* the pointers using rdxtree_for_each(), freeing them, then call this
* function.
*/
void rdxtree_remove_all(struct rdxtree *tree);
#endif /* _RDXTREE_H */