1 /* $NetBSD: ttree.c,v 1.1.1.1 2008/12/22 00:18:37 haad Exp $ */
2
3 /*
4 * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
5 * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
6 *
7 * This file is part of the device-mapper userspace tools.
8 *
9 * This copyrighted material is made available to anyone wishing to use,
10 * modify, copy, or redistribute it subject to the terms and conditions
11 * of the GNU Lesser General Public License v.2.1.
12 *
13 * You should have received a copy of the GNU Lesser General Public License
14 * along with this program; if not, write to the Free Software Foundation,
15 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16 */
17
18 #include "dmlib.h"
19 #include "ttree.h"
20
21 struct node {
22 unsigned k;
23 struct node *l, *m, *r;
24 void *data;
25 };
26
27 struct ttree {
28 int klen;
29 struct dm_pool *mem;
30 struct node *root;
31 };
32
_lookup_single(struct node ** c,unsigned int k)33 static struct node **_lookup_single(struct node **c, unsigned int k)
34 {
35 while (*c) {
36 if (k < (*c)->k)
37 c = &((*c)->l);
38
39 else if (k > (*c)->k)
40 c = &((*c)->r);
41
42 else {
43 c = &((*c)->m);
44 break;
45 }
46 }
47
48 return c;
49 }
50
ttree_lookup(struct ttree * tt,unsigned * key)51 void *ttree_lookup(struct ttree *tt, unsigned *key)
52 {
53 struct node **c = &tt->root;
54 int count = tt->klen;
55
56 while (*c && count) {
57 c = _lookup_single(c, *key++);
58 count--;
59 }
60
61 return *c ? (*c)->data : NULL;
62 }
63
_tree_node(struct dm_pool * mem,unsigned int k)64 static struct node *_tree_node(struct dm_pool *mem, unsigned int k)
65 {
66 struct node *n = dm_pool_zalloc(mem, sizeof(*n));
67
68 if (n)
69 n->k = k;
70
71 return n;
72 }
73
ttree_insert(struct ttree * tt,unsigned int * key,void * data)74 int ttree_insert(struct ttree *tt, unsigned int *key, void *data)
75 {
76 struct node **c = &tt->root;
77 int count = tt->klen;
78 unsigned int k;
79
80 do {
81 k = *key++;
82 c = _lookup_single(c, k);
83 count--;
84
85 } while (*c && count);
86
87 if (!*c) {
88 count++;
89
90 while (count--) {
91 if (!(*c = _tree_node(tt->mem, k))) {
92 stack;
93 return 0;
94 }
95
96 k = *key++;
97
98 if (count)
99 c = &((*c)->m);
100 }
101 }
102 (*c)->data = data;
103
104 return 1;
105 }
106
ttree_create(struct dm_pool * mem,unsigned int klen)107 struct ttree *ttree_create(struct dm_pool *mem, unsigned int klen)
108 {
109 struct ttree *tt;
110
111 if (!(tt = dm_pool_zalloc(mem, sizeof(*tt)))) {
112 stack;
113 return NULL;
114 }
115
116 tt->klen = klen;
117 tt->mem = mem;
118 return tt;
119 }
120