vm_radix.h revision 226645 
1/*
2 * Copyright (c) 2008 Mayur Shardul <mayur.shardul@gmail.com>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 */
27
28#ifndef _VM_RADIX_H_
29#define _VM_RADIX_H_
30
31#include <sys/queue.h>
32
33/* Default values of the tree parameters */
34#define	VM_RADIX_WIDTH	5
35#define	VM_RADIX_COUNT	(1 << VM_RADIX_WIDTH)
36#define	VM_RADIX_MASK	(VM_RADIX_COUNT - 1)
37#define	VM_RADIX_LIMIT	howmany((sizeof(vm_pindex_t) * NBBY), VM_RADIX_WIDTH)
38
39/* Calculates maximum value for a tree of height h. */
40#define	VM_RADIX_MAX(h)							\
41	    ((h) == VM_RADIX_LIMIT ? ((vm_pindex_t)-1) :		\
42	    (((vm_pindex_t)1 << ((h) * VM_RADIX_WIDTH)) - 1))
43
44struct vm_radix_node {
45	SLIST_ENTRY(vm_radix_node) next;
46	void 		*rn_child[VM_RADIX_COUNT];	/* child nodes. */
47    	uint16_t	rn_count;			/* Valid children. */
48};
49
50struct vm_radix {
51	struct 	vm_radix_node *rt_root; 	/* Root node. */
52	int 	rt_height; 			/* Number of levels + 1. */
53};
54
55int 	vm_radix_insert(struct vm_radix *, vm_pindex_t, void *);
56void	*vm_radix_remove(struct vm_radix *, vm_pindex_t);
57void	*vm_radix_lookup(struct vm_radix *, vm_pindex_t);
58int	vm_radix_lookupn(struct vm_radix *rtree, vm_pindex_t start,
59	    vm_pindex_t end, void **out, int cnt, vm_pindex_t *next);
60void	*vm_radix_lookup_ge(struct vm_radix *, vm_pindex_t);
61void	*vm_radix_lookup_le(struct vm_radix *, vm_pindex_t);
62void 	vm_radix_shrink(struct vm_radix *);
63
64#endif /* !_VM_RADIX_H_ */
65