1 /* $Id: kRbGetWithParent.h 35 2009-11-08 19:39:03Z bird $ */
2 /** @file
3 * kRbTmpl - Templated Red-Black Trees, Get Node With Parent.
4 */
5
6 /*
7 * Copyright (c) 1999-2009 Knut St. Osmundsen <bird-kStuff-spamix@anduin.net>
8 *
9 * Permission is hereby granted, free of charge, to any person
10 * obtaining a copy of this software and associated documentation
11 * files (the "Software"), to deal in the Software without
12 * restriction, including without limitation the rights to use,
13 * copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the
15 * Software is furnished to do so, subject to the following
16 * conditions:
17 *
18 * The above copyright notice and this permission notice shall be
19 * included in all copies or substantial portions of the Software.
20 *
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
22 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
23 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
24 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
25 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
26 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
27 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28 * OTHER DEALINGS IN THE SOFTWARE.
29 */
30
31 /**
32 * Gets a node from the tree and its parent node (if any).
33 * The tree remains unchanged.
34 *
35 * @returns Pointer to the node holding the given key.
36 * @param pRoot Pointer to the Red-Back tree's root structure.
37 * @param ppParent Pointer to a variable which will hold the pointer to the partent node on
38 * return. When no node is found, this will hold the last searched node.
39 * @param Key Key value of the node which is to be found.
40 */
KRB_FN(GetWithParent)41 KRB_DECL(KRBNODE *) KRB_FN(GetWithParent)(KRBROOT *pRoot, KRBNODE **ppParent, KRBKEY Key)
42 {
43 register KRBNODE *pNode;
44 register KRBNODE *pParent;
45
46 KRB_READ_LOCK(pRoot);
47
48 pParent = NULL;
49 pNode = KRB_GET_POINTER_NULL(&pRoot->mpRoot);
50 while ( pNode != NULL
51 && KRB_CMP_NE(pNode->mKey, Key))
52 {
53 pParent = pNode;
54 if (KRB_CMP_G(pNode->mKey, Key))
55 pNode = KRB_GET_POINTER_NULL(&pNode->mpLeft);
56 else
57 pNode = KRB_GET_POINTER_NULL(&pNode->mpRight);
58 }
59
60 KRB_READ_UNLOCK(pRoot);
61
62 *ppParent = pParent;
63 return pNode;
64 }
65
66